1630.7 Ub-778 C.3 iv^rsity of fllinipis at Ut:]b4na<-CQa,mpaign Coil^gieiof Agr^iculture ' .* , ■ " looper^tioii^With the Soil!Conservation Service, U.S. Department of Agriculture Agi^4^UtA;al/Experiment St^i date due Soils of Illinois By J.B. Fehrenbacher, J.D. Alexander, I.J. Jansen, R.G. Darmody, R.A. Pope, and M.A. Flock, University of Illinois at Urbana Champaign; ErE. Voss, J.W. Scott, W.F. Andrews, and LJ. Bushue, Soil Conservation Service, U.S. Department of Agriculture Bulletin 778 University of Illinois at Urbana Champaign College of Agriculture Agricultural Experiment Station in Cooperation with the Soil Conservation Service, U.S. Department of Agriculture. 1984. ILLINOIS STATE LIBRARY AUTHORS Department of Agronomy, University of Illinois at Urbana-Champaign: J. B. Fehrenbacher, Professor of Pedology Emeritus; J. D. Alexander and I. J. Jansen, Associ¬ ate Professors of Pedology; R. G. Darmody, Assistant Professor of Pedology; R. A. Pope, formerly Assistant Professor of Soil Management; M. A. Flock, formerly Assistant Agronomist. Soil Conservation Service, U.S. Department of Agriculture: E. E. Voss, State Soil Scientist; J. W. Scott, Assistant State Soil Scientist; W. F. Andrews and L. J. Bushue, Soil Scientists. The authors are indebted to other soil scientists involved in the Soil Survey of Illinois for their help in the many studies that have led to the publication of this bulletin. 8M—3-84--,‘i7I2I—RGM CONTENTS SOIL ASSOCIATIONS OF ILLINOIS. 1 Soil Association 1 (Port Byron-Joy Soils).14 Soil Association 2 (Tama-Muscatene-Sable Soils).14 Soil Association 3 (Tama-lpava-Sable Soils).14 Soil Association 4 (Herrick-Virden-Piasa Soils).15 Soil Association 5 (Oconee-Cowden-Piasa Soils).16 Soil Association 6 (Hoyleton-Cisne-Huey Soils).18 Soil Association 7 (Winnebago-Durand-Ogle Soils).20 Soil Association 8 (Broadwell-Waukegan-Pillot Soils).20 Soil Association 9 (Catlin-Flanagan-Drummer Soils).21 Soil Association 10 (Wenona-Rutland-Streator Soils).22 Soil Association 11 (Plano-Proctor-Worthen Soils) .22 Soil Association 12 (Saybrook-Dana-Drummer Soils).25 Soil Association 13 (Griswold-Ringwood Soils).26 Soil Association 14 (Varna-Elliott-Ashkum Soils).26 Soil Association 15 (Symerton-Andres-Reddick Soils).27 Soil Association 16 (Swygert-Bryce-Mokena Soils).28 Soil Association 17 (Clarence-Rowe Soils).29 Soil Association 18 (Harco-Patton-Montgomery Soils).30 Soil Association 19 (Martinton-Milford Soils).30 Soil Association 20 (Lorenzo-Warsaw-Wea Soils).31 Soil Association 21 (Jasper-LaHogue-Selma Soils).33 Soil Association 22 (Sparta-Dickinson-Onarga Soils).34 Soil Association 23 (Channahon-Dodgeville-Ashdale Soils).35 Soil Association 24 (Lawson-Sawmill-Darwin Soils).36 Soil Association 25 (Houghton-Palms-Muskego Soils).38 Soil Association 31 (Seaton-Timula Soils).39 Soil Association 32 (Fayette-Rozetta-Stronghurst Soils).39 Soil Association 33 (Alford-Muren-lva Soils).40 Soil Association 34 (Clinton-Keomah-Rushville Soils).42 Soil Association 35 (Hosmer-Stoy-Weir Soils).42 Soil Association 36 (Ava-Bluford-Wynoose Soils).45 Soil Association 37 (Westville-Pecatonica-Flagg Soils).45 Soil Association 38 (Middletown-Tell-Thebes Soils).46 Soil Association 39 (Birkbeck-Sabina-Sunbury Soils).47 Soil Association 41 (St. Charles-Camden-Drury Soils).48 Soil Association 42 (Dodge-Russell-Miami Soils).49 Soil Association 43 (Kidder-McHenry Soils).50 Soil Association 44 (Morley-Blount-Beecher Soils).51 Soil Association 45 (St. Clair-Nappanee-Frankfort Soils).52 Soil Association 46 (Markland-Colp-Del Rey Soils).53 Soil Association 48 (Casco-Fox-Ockley Soils).53 Soil Association 49 (Martinsville-Sciotoville Soils).54 Soil Association 50 (Oakville-Lamont-Alvin Soils).55 Soil Association 51 (Ritchey-New Glarus-Palsgrove Soils.56 Soil Association 52 (Alford-Goss-Baxter Soils).58 Soil Association 53 (Alford-Wellston Soils).59 Soil Association 54 (Hosmer-Zanesville-Berks Soils).60 Soil Association 55 (Grantsburg-Zanesville-Wellston Soils).60 Soil Association 56 (Derinda-Schapville-Eleroy Soils).62 Soil Association 57 (Haymond-Petrolia-Karnak Soils).63 DEVELOPMENT OF ILLINOIS SOILS.65 Soil Parent Materials.66 Climate.69 Vegetation.70 Relief and Drainage.70 Time.71 MAJOR SOIL ORDERS IN ILLINOIS.71 Mollisols.72 Alfisols. 72 Entisols.73 Inceptisols.73 Histosols.73 PROGRESS OF SOIL SURVEYS IN ILLINOIS.73 Counties with Modern Published Surveys.74 Counties with Completed Surveys to be Published Soon .74 Counties with Soil Surveys in Progress.74 Counties in Need of Modern Soil Surveys.74 ALPHABETICAL LIST OF ILLINOIS SOILS AND SOIL ASSOCIATION AREAS.75 NUMERICAL LIST OF ILLINOIS SOILS AND SOIL ASSOCIATION AREAS 83 Illinois soils vary in their properties and producing capacities. Large areas of the state have soils that are among the most productive in the world. Other areas have soils that, because they are too steep or drouthy or have some other undesirable features, are not productive for the commonly cultivated field crops. Often these less productive soils can be used to advantage for pasture, forage, and forest production, or for hunting or other recreational purposes. Many of the current problems with soils are the result of improper use and management. The solution to some of these problems lies in better fit¬ ting the uses of the soils to the characteristics and qualities of the soils. To make the best use of the soils of Illinois, it is neces¬ sary to understand the nature and properties of the soils and to know how and where these soils occur in the state. This publication, which replaces Illinois Agricultural Experiment Station Bulletin 725, discusses the general properties, problems, and uses of Illinois soils and de¬ scribes the response of crops grown on these soils to soil treatment. The accompanying General Soil Map of Illi¬ nois shows the location and extent of the soil associations of the state. The map has been greatly enlarged and pro¬ duced in much more detail. The approximately 430 soils currently recognized in Illinois are now grouped in 50 soil associations rather than the 26 previously used. A new key to Illinois soils has been added, and the descrip¬ tions and tables of soil characteristics for each soil asso¬ ciation have been revised. This bulletin is intended to provide a broad picture of the soil resources and soil conditions in the state. It can be used for locating land that has desirable qualities for agricultural, urban, industrial, and engineering pur¬ poses, as well as for broad land-use planning and zoning. Farmers and farm managers, foresters, engineers, in¬ vestors, land appraisers, zoning and planning commis¬ sioners, real estate dealers, subdividers, and home builders can use this information for their various needs. For many specific purposes, however, more detailed informa¬ tion, such as that given in county soil reports or gained from on-site studies, is needed after a general area has been studied and selected. (See page 74 for a list of the Illinois county soil reports available.) A number of publications are available that contain specific information about the use of Illinois soils for various purposes. Drainage and irrigation guides for Illinois can be obtained from the Department of Agri¬ cultural Engineering, University of Illinois at Urbana- Champaign. Information on the use of soils for engineer¬ ing, urbanization, septic tanks, recreation, woodland, and wildlife is available from the USDA Soil Conservation Service district offices and county Extension offices. Soils are classified and mapped on the basis of a num¬ ber of properties, including the kind, thickness, and arrangement of horizons or layers, and the color, texture, structure, reaction, consistency, and mineralogical and chemical composition of those horizons. Features such as slope, stoniness, degree of erosion, permeability, and total thickness of profile are also important in determining the use and crop adaption of soils. Any soil, however, will exhibit a range within the limits of these properties, and the boundaries between different kinds of soils in the field may or may not be sharp. Soils tend to form a continuum on the earth’s surface, and one soil usually grades gradu¬ ally to others. The boundaries or limits to the range of one kind of soil define that soil. These boundaries are not as distinct as those of individual plants or animals. It is no less important, however, that we define and classify soils on the basis of their properties so that we can remember their significant properties, organize our knowl¬ edge of them, show relationships among them and be¬ tween them and their environment, and predict their response and behavior under various uses and manage¬ ment systems. SOIL ASSOCIATIONS OF ILLINOIS The soil associations shown on the General Soil Map of Illinois are composed of several related soil series or kinds of soils that developed from similar parent material and that have similar surface-soil color. The soil associa¬ tions are named from two or more of their important soil series. The degree of development may vary some¬ what among soils in an association. They also differ in properties related to the internal drainage or degree of wetness during their development. The range in drainage class, which includes “well,” “moderately well,” “some¬ what poor,” and “poor,” is referred to in this publication as a drainage sequence. The soils in an association tend to occur in a characteristic pattern in the landscape that is often repeated. However, the proportion of the various soils changes from place to place, depending largely upon slope and natural drainage. In the Key to Illinois Soils (pages 5 to 13) the major soils in the various associations are grouped on the basis of the parent materials from which they have formed, their surface-soil color, degree of development, and nat¬ ural soil drainage. To find information on a particular soil, refer to the alphabetical or numerical lists of soils on pages 75 to 84. The alphabetical list includes the family and subgroup classification of each soil series (see pages 71 to 73 for a discussion of soil classification). Both lists give the numbers indicating the associations in which the soils occur. Some soils, particularly the minor ones, occur in 1 2 Bulletin 778 more than one association. Soil parent materials, as well as the other factors in soil formation, are discussed on pages 66 to 71. Surface-soil color is a reasonably accurate guide to the organic matter content of Illinois soils. In general, they are either dark-colored (developed under grass or prairie) or light-colored (developed under forest). The moder¬ ately dark-colored soils developed under mixed forest and grass, and are transitional between the two major surface- soil color classes. Moderately dark-colored soils are shown in the same soil association as the light-colored soils on the General Soil Map and in the Key to Illinois Soils. Two exceptions are associations 5 and 6, where the soils formed under grass but are strongly to very strongly de¬ veloped and dark to moderately dark-colored. In associa¬ tion 56, dark, moderately dark, and light-colored soils are also shown in the same soil association on the soil map and in the Key to Illinois Soils because the areas of each are often small or narrow. A soil’s degree of development is the extent of weather¬ ing and change the parent materials have undergone in the formation of the soil. During formation, soils develop horizons or layers. In weakly developed soils, these hori¬ zons are not very distinct, but in strongly developed soils they are generally well differentiated in such properties as color, texture, and structure. The changes in appearance and physical properties associated with increasing degree of development are usually accompanied by chemical changes such as increased weathering of soil minerals, greater acidity, and low'er plant-nutrient content. Among the dark-colored soils of the state, the flat, poorly drained soils with fine-textured surface horizons in each associa¬ tion are usually less developed than the related, better drained soils. The degree of development is usually best expressed in the somewhat poorly drained soil of a drain¬ age sequence, probably because its water table and mois¬ ture regime fluctuate more than those of poorly drained or well-drained associated soils. The nearly level, somewhat poorly and poorly drained major soils in soil associations 1 through 6 represent various degrees of development in what has become known as the Illinois soil development sequence (also known as the Illinois maturity sequence of soils). The soil series in this sequence and their degree of develop¬ ment within the range of Illinois soils are as follows: Joy, weak; Muscatine, moderate; Ipava, moderate-moderately strong; Herrick, moderately strong; Cowden, strong; Cisne, strong to very strong. Soils in this sequence formed under grass in loess, which thins systematically from the very thick deposits in association 1 (greater than 25 feet), through associations 2, 3, 4, 5, and finally, to association 6, to where it is only about 3 or 4 feet thick. The range in development from weak in association 1 to very strong in association 6 is due largely to the presence below the loess of a slowly or very slowly permeable paleosol, the Sanga¬ mon soil that formed in Illinoian-aged glacial drift. As the loess becomes thinner with increasing distance from its source, the depth of the relatively impermeable pa¬ leosol gradually decreases. Its presence at shallower and shallo'.' cr depths created an increasingly wet environ¬ ment in the overlying loess, promoting greater mineral weathering and a stronger degree of soil development. The natural internal soil drainage class refers to the degree of wetness under which the soils formed, not to artificial drainage. The natural soil drainage classes may indicate whether drainage is needed but do not indicate drainability. The approximate acreage and proportionate extent of each soil association in the state are listed on page 3. All acreages are rounded to the nearest 100 and all percent¬ ages to the nearest l/IO. The total land area, inland water area, and total state area are also listed. Total land area is the difference between the total acreage of the state and that of the inland water. Inland water includes lakes, reservoirs, and ponds of 40 acres or more and streams or sloughs Va mile or more wide. In the discussion of the soil associations that begins on page 14, soil horizons or layers are defined as follows. The upper horizon A is commonly called surface soil. The lower part of the A horizon is sometimes referred to as the subsurface soil. The B horizon, which is usually just below the A horizon, is often called subsoil. In most Illinois soils, the subsoil has the highest clay content of any horizon in the soil profile. The C horizon, often referred to as the substratum, is commonly thought of as soil parent material or underlying material. In soil profile descriptions, subdivisions of the three major horizons are defined and indicated by letter and number (Al, A2, Bl, B2, B3, Cl, etc.) as shown in Figure 1. The descriptive terms for slope have the following gradients: nearly level, 0 to 2 percent; gently sloping, 2 to 5 percent; sloping, 5 to 10 percent; strongly sloping, 10 to 15 percent; moderately steep, 15 to 20 percent; steep, 20 to 30 percent; and very steep, more than 30 percent. The discussion of each soil association is accompanied by a table giving the following information for each soil: slope range; thickness, texture, average percentage of organic matter in the plow layer, and lime group of the surface soil; thickness, texture, natural drainage class, permeability, and P (phosphorus) and K (potassium) supplying-power of the subsoil; texture and material of the substratum; available water to a depth of 60 inches for crops commonly grown in Illinois; erodibility factor; and grain crop productivity on 0- to 2-percent slopes at high and average levels of management. Soils of Illinois 3 Acreage and Percentage of Various Soil Associations in Land Area of Illinois Soil association Land area No. Name Acres Percent of state 1 Port Byron-Joy 86,800 0.2 2 Tama-Muscatine-Sable 1,629,400 4.6 3 Tama-Ipava-Sable 3,043,300 8.5 4 Herrick-Virden-Piasa 1,052,700 2.9 5 Oconee-Cowden-Piasa 608,000 1.7 6 Hoyleton-Cisne-Huey 1,508,600 4.2 7 Winnebago-Durand-Ogle 83,200 0.2 8 Broadwell-Waukegan-Pillot 166,500 0.5 9 Catlin-Flanagan-Drummer 2,104,600 5.9 10 Wenona-Rutland-Streator 134,400 0.4 11 Piano-Proctor-Worthen 1,859,300 5.2 12 Saybrook-Dana-Drummer 1,228,800 3.4 13 Griswold-Ringwood 97,100 0.3 14 Varna-Elliott-Ashkum 983,100 2.7 15 Symerton-Andres-Reddick 175,200 0.5 16 Swygert-Bryce-Mokena 528,400 1.5 17 Clarence-Rowe 116,200 0.3 18 Harco-Patton-Montgomery 111,000 0.3 19 Martinton-Milford 338,600 1.0 20 Lorenzo-Warsaw-Wea 237,500 0.7 21 J asper-LaHogue-Selma 443,700 1.2 22 Sparta-Dickinson-Onarga 761,000 2.1 23 Channahon-Dodgeville-Ashdale 197,100 0.6 24 Lawson-Sawmill-Darwin 2,326,100 6.5 25 Houghton-Palms-Muskego 75,800 0.2 31 Seaton-Timula 209,400 0.6 32 Fayette-Rozetta-Stronghurst 2,252,800 6.3 33 Alford-Muren-Iva 356,200 1.0 34 Clinton-Keomah-Rushville 2,804,600 7.9 35 Hosmer-Stoy-Weir 1,221,400 3.4 36 Ava-Bluford-Wynoose 2,387,500 6.7 37 Westville-Pecatonica-Flagg 127,900 0.4 38 Middletown-Tell-Thebes 90,400 0.3 39 Birkbeck-Sabina-Sunbury 454,300 1.3 41 St. Charles-Camden-Drury 371,500 1.0 42 Dodge-Russell-Miami 381,000 1.1 43 Kidder-McHenry 65,800 0.2 44 Morley-Blount-Beecher 642,200 1.8 45 St. Clair-Nappanee-Frankfort 149,200 0.4 46 Markland-Colp-Del Rey 298,900 0.8 48 Casco-Fox-Ockley 163,400 0.5 49 Martinsville-Sciotoville 101,300 0.3 50 Oakville-Lamont-Alvin 467,700 1.3 51 Ritchey-New Glarus-Palsgrove 205,700 0.6 52 Alford-Goss-Baxter 188,100 0.5 53 Alford-Wellston 116,400 0.3 54 Hosmer-Zanesville-Berks 489,800 1.4 55 Grantsburg-Zanesville-Wellston 388,000 1.1 56 Derinda-Schapville-Fleroy 89,100 0.3 57 Haymond-Petrolia-Karnak 1,738,700 4.9 Total land area. Total inland water area. Total area of Illinois. 100.0 4 Bulletin 778 Although the meaning of most of the soil characteris¬ tics listed in the tables is apparent, some characteristics require explanation. In the surface soil, a thick, black (high in organic matter) silt loam or loam is most desir¬ able. This surface soil is lime group B. Lime groups are based on the soils’ texture and organic matter content. The texture described in the tables is the principal tex¬ ture occurring in Illinois. Permeability is the integrated permeability of the entire subsoil, and does not necessarily apply to individual sub¬ horizons. Moderate permeability is considered the most desirable. Since water flow is restricted in soils having slow or very slow permeability, tile are usually not recom¬ mended in those needing drainage. Soils with rapid or very rapid permeability, such as sandy soils, do not hold much water even at field capacity. If the soils are wet because of their low-lying position, drainage may cause drouth problems if the water table is lowered too much. The P and K supplying-power of the subsoil indicates the amount of these nutrients that plants can use once their roots penetrate that layer. Available water to 60 inches reflects the soil’s water-storage capacity. If a root- restricting layer such as a fragipan is present, the avail¬ able water is reduced. The erodibility factor indicates the ease with which soil particles are detached by rainfall. Productivity indexes and crop yield estimates are con¬ tained in Illinois Cooperative Extension Service Circular 1156, Soil Productivity in Illinois. Only the high and average productivity indexes are given here. Crop adap¬ tation is related to climate and soil characteristics. Maps showing the average annual temperature and precipita¬ tion and the average number of frost-free days in Illinois are on pages 69 and 70. Most of the common field crops can be grown in all areas of the state. Spring oats are best adapted to northern Illinois. Production of cotton, very little of which is grown in Illinois, is restricted to the extreme southern end of the state. Tree fruits such as apples and peaches are best adapted to the southern one- half of the state. Forests are more extensive in southern than in northern Illinois, but more as a result of topog¬ raphy, soils, and native vegetation than of climate. Most com is grown in central and northern Illinois. Most soy¬ beans and wheat are grown in the southern two-thirds of the state, and acreages of oats and hay are highest in the northern one-third. Crop production management is discussed in the Illinois Agronomy Handbook. ( ( The solum (the ge¬ netic soil devel¬ oped by soil-form¬ ing processes). < Horizons of maximum bio¬ logical activity or eluviotion (removal of materials dis- 4 solved or suspended in water) or both. \ ( Horizons of illuviation (ac¬ cumulation of suspended material from A) or maxi¬ mum clay accumulation or blocky or prismatic structure or a combination of these. \ Al: Mineral sail mixed with organic materials; the darkest horizon in many soils and usually the horizon with maximum biological activity. Ap is the plow layer and may ar may not be thicker than Al. A2: Light-colored horizon from which clay and other minerals and organic materials in suspension or solution have been removed. B1: Transitional to A but more like B than A. B2: Horizon of maximum clay or accumulation of iron and organic materials or with maximum develop¬ ment of blocky or prismatic structure. B3: Transitional to C but more like B than C. Cl: Material either similar to or unlike the material from which the solum (A and B horizons) devel¬ oped. Although the material may have undergone some weathering, it has not been greatly affected by soil-forming processes. R; Consolidated bedrock such as sandstone or lime¬ stone. Figure 1. Principal horizons of upland soils. Not every horizon and subhorizon shown here is necessarily present in all soils. (Adapted from Nomenclature of Soil Horizons, USDA Handlxtok 18, pages 174-183. 1951.) Natural internal drainage class Area on Surface Degree of - Parent material soil map color development Well Moderately well Somewhat poor Poor Line Soils of Illinois 5 o e V ta6 O f' (9 u . ,«« C C ^22 .J {« M S I) (/> 2 o 2 k* < -o -o o o *D JZ O 6C 5 J tc 3 E 2 W o X CO V - 00 u ^ 3 (/) U ■§ * e 00 T5 t: o o £ « £ U <= 2 I ;i Q G S J in O'! II •b > X S ^ -2 i) G :«s c 2 J c O ;= a G •o 0 t E S TJ -v O 0 S 2 •o -c 0 oc S G o «c^on^ifttor^ooo>o — c^o^^^»ft^O^*.oooo ■S s -j 0^ .= Ji § §£ § < <£ ■§ •§ 5 S •§ ■£ s j o o s s ■§ -8 s s S J o tj 8 o 0 s s 0; ■o j: 0 be S J .£ E ■§ E - E ■5 S I ^ Soils of Illinois 7 *2 s e e o u o Vi >> i4 ■si &D O -o 0) •So 3 O (A W S ^ ^ mm i *0 C .- 4^ > TS T3 0 0 o •T3 O ^ H c S o c E ;3 ^ o •o 5 CQ 4.^ 1 1 s s Q Q « 0 E ^ ~ m S <7) I S <2 w E U o o S S S J ^ < 2£ <3^ wi O N s s S J o V s s -5 A - te -ts 0 J u 1 ^ CM CM A - 0 o k. u W M Q Q •u -o o o S S o w ■o j= o bO S J E ^ c i CJ ^ .2 c c :r o ^ X *0 *0 o o 0 oc S J o „ bo c (« c C .2 O S -o -o O 0 S S S J E i' E mi Loam (ill, calcareous at < 10 in. 39, 42, 43 Light Weak Hennepin 25 8 Bulletin 778 Medium-textured material < 20 in. thick on reddish silty Moderately dark Moderate Niota 261 clay or clay on loamy sand or sand, calcareous at > 42 in. 45 Moderately dark Moderate Niota. thin A 568 Light Moderate Zwingle 576 Soils of Illinois 9 10 Bulletin 778 ■S 3 3 • M e o u o c/3 a o a JJ o &>! X " O -o ^ .5 3 O g >N ^ E ~o ^ c V o o . ^ ^ 2 O U ea A T3 -2 ^ in in QQ 02 on on in in S 3i on on in in < < in in CQ CO "d -d o 0 S S .E E — — C^l .s V o 5 S - £ ^ 5 c -a 1 I ■§ 2 I ^ Key to Illinois Soil s (continued) _ Natural internal drainage class Area on Surface Degree of - Parent materia] soil map color development Well Moderately well Somewhat poor Poor Line Soils of Illinois 12 Bulletin 778 Medium acid-mildly alkaline silt loam > 40 in. thick on siraiified. Dark to 10-24 in. None-weak Huntington 600 Blackoar 603 281 medium-textured material* Dark to 24-40 in. None-weak -Huntsville 77- Lawson 451 Otter 76 282 Soils of Illinois 13 1 9 C e o u o c/3 tii t: ® 3 O - '-v 1 E E t — CM tJi o CM CM £ t CO r- O 03 CM CM 3 ^ « := O A 0 0 -0 CX. 0^ >^.£ > V o .2 rti fc" H E = &■ Si 4) — •o bU 2 1 2 2 2 -= s II 2 4; w s £ o. ;£ irt C 03 ^ 2 — 03 t'. T3 i I 11 ^ CM ^ — c J- 2 5 o o ^ CO « S •£ *2 00 ir 2 X. O ■5 C >. 3 v 2 c« >- £ v« js £ -i ^ s « 3 CO — .0 00 c £ 4/ ^ 3 i 3 - S i S ■§ “•-1 W »f3* a — CO c •5 ® 0 c ^ F 2 “ -5 i £ O 00 ^ ft. C . « »f3 -P I C S S O ^ . -• ^ o CO 00 00 o .« i' .c C 0 w 4< “7 4> *5 Cfi ^ O 00 o ^ 00 3 E O* <9 < 2 00 II £ i I ^ 0 3 » !? ® « u i: (C E &) ■■ u 0 b i 2 .. *0 t i " £ ■§ J £ >. ^ 2 •• c £ TS ^ II >. U *1^ « t - ^ B " ^ j_- ?s .2 n 5 “ g o " 2 u n " II 2 ■“ ^ “ o -o c 4i C ft fa- CQ S CQ Ml 0 - >' 1 (Q c ^ I -3; II 2 II 2 11 " CQ - ^ CQ 2 E 0 D _0 II II — o i; * -P § " i E -- IS >' CQ II " i/> b' I ^ •• II CQ iC X Iq e ■■ J= CQ - *^0-5 II A I •• 2 I " £ “. u --■ 5 •o . S i '2 W 3 X 1 4 Bulletin 778 Soil Association 1 Port Byron-Joy Soils Soil association 1 occurs in nortliwestern and western Illinois on uplands near the bluffs along the Mississippi River valley in very thick loess areas. The soils formed under grass vegetation and are dark eolored. Soil associa¬ tion 1 usually occurs near association 31, which is its forest soil counterpart. Soil association 1 occupies about 86,800 acres or 0.2 percent of the state’s land area. Port Byron and Joy are the predominant soils in this association. Joy, which is somewhat poorly drained, occurs on the more level areas. Port Byron, the better drained soil, is located on the more sloping areas or narrower ridge tops. Tallula, one of the minor soils, com¬ monly occurs on side slopes. The poorly drained Edging- ton soils occur in depressions. The soils of association 1 are weakly developed. They represent the first stage or weak degree of development in the Illinois soil development sequence. Except for Edg- ington, the soils in this association have silt loam texture throughout their profiles and lack layers or horizons of significant clay accumulation in their subsoils. Because these soils are silty, they have high available-water holding capacities and are very productive, except in those few areas that have sandy substrata. The productivity of some areas of Joy can be improved by tiling. Areas of Edgington should be drained by tiling or use of open ditches or both. A more common problem than drainage in this association is erosion on the more sloping areas. Fertility problems require sustained atten¬ tion but can easily be managed with a good soil testing and soil treatment program. Various characteristics and the productivity indexes of the soils in association 1 arc given in Table 1. Soil Association 2 Tama-Muscatine-Sable Soils Soil association 2 occurs in northwestern and western Illinois. It quite often adjoins association 1, but occurs in slightly thinner loess and is a little farther removed from the Mississippi River valley loess source. This association covers 1,629,400 acres or 4.6 percent of the state’s land area. Association 2 includes Muscatine soils, which represent the second stage or moderate degree of soil development in the Illinois soil development sequence. The major soils of association 2, Tama, Muscatine, and Sable, have silty clay loam subsoils, are moderately permeable, and have high available-soil moisture holding capacities. They provide a very good rooting medium for most crops, especially com and soybeans, and are among the most productive soils in the state. The Tama soils are moder¬ ately well and well drained, and occur on side slopes along drainageways and on narrow or rounded ridgetops. Because they are sloping soils, most areas of Tama are subject to erosion unless adequately protected. The Muscatine soils occur on gentle slopes and are somewhat poorly drained. Sable soils are located on flats or in slightly depressional areas and are poorly drained. Both of these soils can be adequately drained by tiling. The minor, poorly drained soils of this association, such as Denny, Edgington, and Harpster, occur on nearly level or slightly depressional areas. Edgington and Harpster can be tile drained, but Denny, because of its slowly perme¬ able subsoil, must be drained by ditches or by tile through a surface inlet. Minor, sloping soils such as Assumption, Keller, and Tallula are subject to erosion if planted in row crops. Most areas of these soils, especially those hav¬ ing slopes of more than about 5 percent, should be planted in hay or pasture crops. Even though association 2 is one of the most produc¬ tive areas in the state, it does have fertility problems. Normally, these problems can easily be solved through regular soil testing and soil treatment programs. Since Harpster soils are calcareous (limey) on the surface, they should not be limed. Because of the high content of lime in their surfaces, these soils may also need more phos¬ phorus and potassium than other soils in this area. Var¬ ious characteristics and the productivity indexes of the soils in association 2 are given in Table 2. Soil Association 3 Tama-lpava-Sable Soils Soil association 3 is located in central and west central Illinois, and is most extensive on the flat to gently sloping uplands on the divides between streams. It occupies 3,043,300 acres or 8.5 percent of the state’s land area. This association includes highly productive, dark-colored soils that have developed in loess under native prairie grasses. These soils, particularly the Ipava, are in the third stage of the soil development sequence in Illinois, and are considered to be moderately to moderately strongly developed. Many of the soils, except for the Ipava, are the same as those found in soil association 2. The major soils of association 3 are considered to be the prairie or dark-colored counterpart of the light-colored soils of association 34, which formed under forest. The soils of this area contain slightly more clay than the soils in association 2. Soils in association 3 are w’ell structured and permeable, and, because of their high capacity to store water, are well suited to intensive corn and soybean production. The Tama soils occur on narrow, rounded ridgetops and on side slopes. They are moderately well drained and well drained, and must be carefully managed to protect Soils of Illinois 1 5 Table 1. Characteristics and Productivity Indexes of Soil Association 1 — Port Byron-Joy Soils^ Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index*’ Slope range, % SuddIv of Texture and material No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability P K High mgmt. Avg. mgmt. 272 Edeington 0-1 31 sil 3.5 B 24 sicl Poor Mod. slow-slow L M sil loess 11.9 0.32 125 100 275 Joy 0-5 19 sil 3.0 B 29 sil SW. poor Moderate M H sil loess 13.0 0.28 155 128 277 Port Byron 1-12 17 sil 3.0 B 31 sil Well-mod. well Moderate H H sil loess 12.9 0.32 145 120 562 Port Byron, san. sub. 1-12 18 sil 3.0 B 24 sit-l Well-mod. well Mod.-rapid M M aeolian fs 9.1 0.32 125 100 34 Tallula 5-20 15 sil 3.0 B 12 sil Well-mod. well Moderate M M calc, sil loess 12.5 0.32 120 95 ^ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Table 2. Characteristics and Productivity Indexes of Soil Association 2 — Tama-Muscatine-Sable Soils^ Surface soil Subsoil Sub- stratum Available Productivity No. and name of soil series Slope range, % Avg. thick¬ ness, in. Texture Avg. OM in plow layer, % Lime group Avg. thick¬ ness, in. Texture Natural drainage Permeability Supply of P K Texture and material water to 60 inches, in. Erodi- bility factor, K index" High mgmt. Avg. mgmt. 259 Assumption 2-18 12 sil 3.5 B 35 sicl Well-mod. Mod.-mod. slow M M cl till 10.2 0.32 125 98 well paleoso) 45 Denny 0-2 20 sil 3.0 c 30 sicl Poor Slow L M sil loess 11.4 0.37 110 90 272 Edgington 0-1 31 sil 3.5 B 24 sicl Poor Mod. slow-slow L M sil loess 11.9 0.32 125 100 67 Harpster 0-2 15 sicl 5.5 A 24 sicl Poor Moderate L L sil-1 wash 11.3 0.28 135 110 470 Keller 2-12 10 sil 3.5 B 35 sic-cl-c SW. poor Slow L L cl till pa- 9.3 0.37 95 80 leosol 41 Muscatine 0-3 16 sil 4.5 B 34 sicl SW. poor Moderate M H sil loess 12.2 0.28 160 130 68 Sable 0-2 20 sicl 5.5 A 27 sicl Poor Moderate L M sil loess 12.3 0.28 155 128 34 Tallula 5-20 15 sil 3.0 B 12 sil Well-mod. Moderate M M sil loess 12.5 0.32 120 95 well 36 Tama 1-20 14 sil 3.5 B 35 sicl Well-mod. Moderate H H sil loess 12.1 0.32 150 125 well ^ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. them from erosion. Some have already lost part of their naturally dark-colored surface soil and now have subsoil material mixed into the plow layer. Ipava and Sable soils commonly occur on broad, nearly flat ridge tops. They are naturally wet and require artificial drainage for optimum productivity. Ipava soils, which are somewhat poorly drained, occur on gentle slopes on the moderately wide ridge tops and along the edges or on the very slightly elevated areas of wider ridge tops. Sable soils are poorly drained and occupy the flatest areas toward the center of the broad ridge tops. Edinburg, Hartsburg, Harpster, and Denny, which are among the minor soils in this association, commonly occur in flat to slightly depressional areas on ridgetops and are associated with Sable or Ipava soils. They are naturally wet and require artificial drainage. Elkhart, Tallula, Velma, Keller, and Assumption soils occur on gently sloping to steep side slopes along major drainage- ways. Erosion is the principal management problem with these soils. Velma, Keller, and Assumption are on sloping areas where the loess is thin. The lower part of each of these soils developed in the underlying glacial till. Harp¬ ster and Tallula soils are calcareous at the surface; Elkhart and Hartsburg soils are acid at the surface but calcareous within 40 inches of the surface. Various characteristics and the productivity indexes of the soils in association 3 are given in Table 3. Soil Association 4 Herrick-Virden-Piasa Soils Soil association 4 occurs in west central Illinois, primarily in Hancock and Adams counties between the Illinois and Mississippi rivers and in an area east of the mouth of the Illinois River extending from Jersey County south to St. Clair and Washington counties and east to Christian and Shelby counties. These soils are most ex¬ tensive on the flat to gently sloping uplands on the divides or ridges between major streams. The soils cover 1,052,700 acres or 2.9 percent of the state’s land area. This association includes moderately to strongly devel¬ oped soils that formed under grass in loess, ranging on 16 Bulletin 778 nearly level areas from about 5 to 7 feet in thickness. In the more sloping areas, the soils formed in thinner loess over paleosols. Soil association 4 is the last association of the Illinois soil development sequence that is dark-colored enough to be included in the Mollisol soil order (see page 72). Soil association 34 is considered to be the forested counterpart of soil associations 3 and 4. The Tama soils, which occur on ridgetops and side slopes in association 4, are medium-textured throughout, being high in silt and very low in sand. They are well structured and permeable and have a high capacity to store water for plants. They are used primarily for inten¬ sive corn and soybean production. Tama soils are moderately well drained and well drained, and must be carefully managed to protect them from erosion. Many areas have already lost part of their naturally dark- colored surface soil to erosion. Herrick and Virden soils commonly occur on nearly flat ridgetops. Herrick normally has some surface slope and is somewhat poorly drained, while Virden occurs on flatter areas and is poorly drained. Tile function some¬ what slowly but usually adequately in these two soils, which represent stage 4 in the Illinois soil development sequence. These soils contain slightly higher clay con¬ centrations in their subsoils and are slightly less perme¬ able than soils of similar natural soil drainage in associa¬ tions 1, 2, and 3 of the soil development sequence. Piasa, Tamalco, Darmstadt, Huey, and Walshville, which are among the minor soils in this association, have excessively high sodium levels. Piasa and Huey soils de¬ veloped in loess and are commonly associated with Virden and Herrick soils in flat to depressional areas on ridgetops. They are poorly drained and are too imperme¬ able for tile to function efTectively in them. Tamalco, Darmstadt, and Walshville, which have better natural drainage, occur on areas having a convex or more slop¬ ing surface. Piasa, Tamalco, Darmstadt, and Huey soils respond to good soil management, but seldom, if ever, equal the productivity of associated soils such as Herrick and Virden. The more or less random occurrence and variable size and shape of the high sodium soils among nonsodium soils create difficult management problems. In general, both the high and low sodium soils must be farmed together. Where they are intimately mixed, they are often shown as complexes on county soil maps. Douglas and Harrison soils occur on sloping areas where the loess is about 40 to 60 inches thick over gray or reddish paleosols. The upper part of their profiles (in loess) is similar to that of Tama. The lower part con¬ tains more sand and pebbles. Coatsburg, Keller, Assump¬ tion and Pana have developed in less than 40 inches of loess and the underlying paleosol. They commonly occur on gently sloping to steep upper side slopes, coves, and narrow, sloping ridgetops. Velma and Walshville soils have developed in glacial till and commonly occur on moderately steep to steep lower side slopes. Various characteristics and the productivity indexes of the soils in association 4 are given in Table 4. Soil Association 5 Oconee-Cowden-Piasa Soils Soil association 5 occurs in southwestern and south central Illinois, from Randolph County on the southern end, northward to Montgomery County, and then east¬ ward to Clark County. It covers about 608,000 acres or 1.7 percent of the state’s land area. Table 3. Characteristics and Productivity Indexes of Soil Association 3 — Tama-Ipava-Sable Soils' Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index*^ Slope range, % Texture and material No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability Supply of P K High mgmu Avg. mgmt. 259 Assumption 2-18 12 sil 3.5 B 35 sicl Well-mod. well Mod-mod. slow M M cl till paleosol 10.2 0.32 125 98 45 Denny 0-2 20 sil 3.0 c 30 sicl Poor Slow L M sil loess 11.4 0.37 110 90 249 Edinburg 0-1 16 sici 3.5 A 35 sicl Poor Slow-mod. slow L M sil loess 11.3 0.28 130 107 567 Elkhart 3-20 10 sil 3.0 B 20 sicl Well-mod. well Moderate M H sil loess 12.1 0.32 125 100 67 Harpster 0-2 15 sicl 5.5 A 24 sicl Poor Moderate L L $il-l wash 11.2 0.28 135 110 244 Hartsburg 0-2 17 sicl 4.0 A 18 sicl Poor Moderate L L sil loess 12.2 0.28 140 118 43 Ipava 1-4 16 sil 4.5 B 34 sicl SW. poor Moderate M H sil loess 12.2 0.28 160 130 470 Keller 2-12 10 sil 3.5 B 35 sic stratum Available Productivity Slope range, % Avg, thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. Texture and material water to 60 inches, in. Erodi- bility factor, K index'’ No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability Supply of P K High mgrot. Avg. mgmt. 287 Chauncey 0-3 30 sil 3.0 c 25 sicl-sic Poor Slow L L loamy wash 11.8 0.37 120 95 2 Cisne 0-3 17 sil 2.0 c 38 sicl-sic Poor V. slow L L lo wash on till paleosoi 10.9 0.37 115 88 660 Coatsburg 5-20 12 sil 4.0 B 48 cl-c Poor Slow-v. slow M M cl paleo- sol 8.8 0.37 75 58 620 Darmstadt 1-10 11 sil 2.0 C 28 sicl-sic SW. poor Slow-v. slow M L sil-1 wash 7.4 0.43 80 62 48 Ebbert 0-1 20 sil 3.0 B 30 sici Poor-v. poor Slow L L lo wash on till pa- leosol 12.1 0.37 135 110 3 Hoyleton 0-6 13 sil 2.0 C 35 sicl-sic SW. floor Slow L L to wash on till paleosoi 11.1 0.37 115 88 120 Huey 0-2 11 sil 2.0 C 32 sil, sici Poor Very slow L L lo wash on till paleosoi 7.4 0.43 75 58 167 Lukin 1-4 26 sil 2.5 C 25 sicl SW. poor Slow L M lo wash on till paleosoi 11.8 0.37 120 92 218 Newberry 0-3 18 sil 2.5 C 32 sici Poor Slow L L lo wash on till paleosoi 12.0 0.37 120 92 256 Pana 5-15 12 sil 3.0 B 45 gl cl Well Mod. rapid L M gi loam ow. 8.0 0.32 105 85 474 Piasa 0-2 11 sil 3.0 C 35 sicl-sic Poor V. slow-slow M L lo wash on till paleosoi 7.6 0.37 80 65 4 Richview 3-12 12 sil 2.0 c 40 sici Mod. well- well Moderate L L lo wash on till paleosoi 11.8 0.32 110 85 581 Tamalco 1-4 10 sil 2.0 C 32 sicl-sic Mod. well Slow-v. slow L L lo wash on till paleosoi 8.1 0.43 75 60 250 Velma 7-20 14 1 3.5 B 37 cl Well-mod. well Mod.-mod. slow M M 1 till 11.2 0.32 120 92 284 Walshville 4-15 9 1 2.0 C 40 cl Mod. well Very slow L L 1 till 7.7 0.43 65 50 * See abbreviations at end of Key to Illinois Soils, page IS. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. 20 Bullefin 778 permeable. Coatsburg and Velma soils fomied in thin or no loess and Illinoian or Kansan glacial till. Coatsburg soils are poorly drained, have clayey subsoils, and are slow or very slowly penneable. Velma soils are well and moderately well drained and are moderately or moder¬ ately slowly permeable. Most of the forested counterparts of the soils in association 6 arc in soil association 36. Major problems on the less sloping soils in association 6 are restricted permeability, low fertility, and a high water table during wet seasons. Some of these soils have exces¬ sive sodium in the subsoil. On the more sloping soils, erosion, low fertility, and in some areas, low available- water holding capacity are problems. Although some sloping areas of these soils are in per¬ manent pasture or woodland most of this association is cropland. Com, soybeans, wheat, milo, and hay are the principal crops. The soils in this association respond very well to additions of lime and fertilizer and to other good management practices. Drainage, which is needed in the nearly level areas, is best provided by open ditches. Various characteristics and the productivity indexes of the soils in association 6 are given in Table 6. Soil Association 7 Winnebago-Durand-Ogle Soils Soil association 7 occurs in extreme northern Illinois, mainly in Stephenson, Winnebago, Ogle, and Carroll counties. Most areas are small and occur in a scattered pattern. This association occupies about 83,200 acres or 0.2 percent of the state’s land area. These dark-colored soils developed under grass vegeta¬ tion in nearly level to strongly sloping upland areas. They developed in thin loess over reddish, weathered drift (paleosols) of Illinoian age. Although the drift is pre¬ dominantly till, some areas have kame deposits and poorly stratified, water-deposited sediment. The loess covering the till is as thick as 50 inches in the nearly level areas but may be less than 15 inches thick or absent in the strongly sloping areas. These soils occur with or near the light-colored soils of soil association 37, which devel¬ oped in the same kinds of materials, and which are con¬ sidered to be the forested analogues of the soils in association 7. These soils are well drained or moderately well drained, have moderate permeability, and do not need tiling. The Ogle, Durand, and Winnebago soils differ mainly in the thickness of the loess cover over the reddish, weathered drift. Ogle soils have 30 to 50 inches, Durand 15 to 30 inches, and Winnebago less than 15 inches of loess cover. The Ogle soils, which have a silt loam sub¬ stratum, occur only in a small area in southwestern Carroll County. They have weakly developed subsoils in the loess portion of the profile, which are silt loam in texture. Most areas of these soils are used for com, soybeans, small grain, or hay production, but a few strongly sloping areas, particularly of Winnebago soils are maintained in permanent pasture. All are responsive to good manage¬ ment. The Winnebago soils tend to be somewhat drouthy during prolonged periods of dry weather. All of these soils are susceptible to erosion on the steeper slopes, where moderate erosion is common. Various character¬ istics and the productivity indexes of soils in association 7 are given in Table 7. Soil Association 8 Broadwell-Waukegan-Pillot Soils Soil association 8 occurs in a scattered pattern in small areas of central and northwestern Illinois. In central Illinois, these soils occur mainly in Christian, Logan, Mason, and Menard counties, with the largest areas in Logan County. In northwestern Illinois, the association occurs mainly in Whiteside County, with small areas in Carroll and Henry counties. Total areas of this associa¬ tion is about 166,500 acres or 0.5 percent of the state’s land area. Table 7. Characteristics and Productivity Indexes of Soil Association 7 — Winnebago-Durand-Ogle Soils^ Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index^ Slope range, % Texture and material No. and name of soil series plow layer, Texture % Lime group Texture Natural drainage Permeability P K High mgmt. Avg. mgmt. 416 Durand 1-20 13 sil 4.0 B 47 cl Well-mod. well Moderate M H cl paleo- sol 11.0 0.32 130 105 412 Ogle 2-18 15 sil 4.0 B 45 sicl-cl Well Moderate H H cl paleo- sol 11.1 0.32 135 110 574 Ogle, sil. sub. 2-7 14 sil 4.0 B 40 sil-cl Well Moderate H H cl paiec sot 9.8 0.32 105 85 728 Winnebago 2-30 14 sil 4.0 B 46 cl-scl Well-mod. well Moderate M M ci-sl pa- leosol 10.6 0.32 120 95 ^ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Soils of Illinois 21 These dark-colored soils developed in less than 60 inches of loess over loamy sand or sand deposits in upland areas and on terraces or outwash plains. The sandy mate¬ rials are believed to have been deposited by wind in much of this association, with lesser amounts having been de¬ posited by water. The soils developed under grass in nearly level to moderately sloping landscape positions. These soils occur with or near the light-colored soils of soil association 38, which developed in the same kinds of materials under forest and are considered to be the forested counterparts of the soils in association 8. The Lawndale soils in this association are somewhat poorly drained and need tiling for maximum production. The other soils are well or moderately well drained and do not require artificial drainage. Lawndale and Broad- well soils typically have between 40 to 60 inches of loess over the sandy materials and have moderate permeability and moderately developed subsoils. Waukegan and Pillot soils have developed in 20 to 40 inches of loess over the sandy materials; they have moderate permeability in the upper portion of the profile but rapid permeability in the lower portion. Waukegan soils differ mainly from Pillot soils in having weaker developed subsoils of silt loam texture in the loess portion of the profile. The portion of the association occurring in Whiteside and Carroll counties is composed entirely of Waukegan soils. Most of the soils in this association are used for com, soybean, small grain, or hay production and respond well to good management. The Pillot and Waukegan soils tend to be drouthy during prolonged periods of diy' weather because the sand underlying them is at a rela¬ tively shallow depth. Controlling erosion is a problem on the more sloping areas of these soils except for Lawndale, which occurs in level to gently sloping landscape posi¬ tions. Various characteristics and the productivity indexes of the soils in association 8 are given in Table 8. Soil Association 9 Catlin-Flanagan-Drummer Soils Soil association 9 occurs in the east central, central, and north central part of Illinois. The Catlin, Flanagan, and Drummer soils dominate the landscapes in this association. The minor soils, Peotone, Harpster, and Pella, usually occur in scattered, small areas. This a.ssocia- tion has a total area of about 2,104,600 acres or .5.9 per¬ cent of the state’s land area. These soils formed in moderately thick loess (40 to 60 inches) and commonly occur on upland till plains, with many areas appearing to be nearly level. Other areas occur on end moraines, which are the more sloping areas that have 40 to 60 inches of loess extending into regions of thicker loess. These dark-colored soils formed under grass and are moderately to moderately strongly developed. They have high available-water holding capacity and moderate permeability. Slopes of the well drained and moderately well drained Catlin soils range from nearly level to sloping. These soils occur on the higher portion of the landscape or side slopes along drainageways where runoff is medium. Slopes of the somewhat poorly drained Flanagan soils range from nearly level to gently sloping. These soils contain more clay in the subsoil than the Catlin or the Drummer soils. They typically occur on higher parts of the landscape than the poorly drained Drummer soils and have medium to slow runoff. The nearly level, poorly drained Drummer soils are the dominant soil in this association. They have slow to ponded runoff. The light-colored soils in association 39 are the forested analogue of association 9 soils. The minor soils in this association are all poorly drained. The Peotone soils, which usually occur in de¬ pressions, are often drained by means of surface inlets Table 8. Characteristics and Productivity Indexes of Soil Association 8 — Broadwell-Waukegan-Pillot Soils^ Surface soil Subsoil Sub* Avg. Avg. OM Avg. water to 60 inches, in. Erodi- bility factor, K Slope range, % Texture and material No. and name of soil series thick* ness, in. Texture in plow layer, % Lime group thick* ness, in. Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmt. 684 Broadwell 0-12 15 sil 4.0 B 39 sicl Well-mod. well Moderate H H Is-fs aeolian 11.3 0.32 140 118 683 Lawndale 0-3 17 sil 4.0 B 35 sici SW. poor Moderate M H Is-fs aeolian 11.1 0.32 155 128 159 Pillot 0-12 15 sil 3.5 B 21 sicl-scl Well Mod.-rapid M L Is-fs aeolian 8.7 0.32 110 90 564 Waukegan 0-12 15 sil 3.5 B 18 sil-l Well Mod.-rapid M L Is-fs aeolian 8.0 0.32 no 90 ^ See abbreviations at end of Key to Illinoit Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. 22 Bulletin 778 into tile. Since Harpster soils are calcareous (limey), limestone should not be applied to them. Phosphorus and potassium fertilization may have to be higher than with Drummer because of the high pH and tie-up of nutrients in the surface soil of the Harpster. Pella is similar to Drummer in many respects except that it has carbonates (lime) at depths less than 40 inches and is not quite as productive. The Gatlin and Flanagan soils are subject to erosion. Tile drainage of the Flanagan soil will improve crop yields in some years. Surface ditches and tile drainage help improve cro]) yields on the Drummer soils in most years. Most areas of these soils are planted in cultivated crops, particularly com and soybeans. These soils respond to good management and are among the most productive soils in the state. Various characteristics and the produc¬ tivity indexes of the soils in association 9 are given in Table 9. Soil Association 10 Wenona-Rutland-Streator Soils Soil association 10 occurs in a small area of the north central part of Illinois in La Salle, Livingston, Marshall, and Woodford counties. It has a total area of 134,400 acres or 0.4 percent of the state’s land area. Rutland soils dominate most landscapes on which these soils occur. The soils are formed in 40 to 60 inches of loess and the underlying clayey glacial till or lacustrine material. They are nearly level to strongly sloping, and occur on upland till plains or small glacial lakebeds. Since the native vegetation was tall prairie grasses, the soils are dark colored. These soils have a moderate to high available-water holding capacity. They have less available water than thick loess soils because of the silty clay or clay at a depth of 40 to 60 inches, which limits to some extent the depth of root penetration by farm crops commonly grown in the area. Pemieability is moderately slow in the loess subsoil and slow in the underlying material. The slope of the well-drained Wenona soils ranges from gently to strongly sloping, and surface runoff is medium. Wenona soils occur on the highest portion of the landscape or on side slopes along drainageways. The slope of the some¬ what poorly drained Rutland soils ranges from nearly level to gently sloping. These soils occur on the stable part of the landscape, and surface runoff is slow to medium. The poorly drained Streator soils have nearly level slopes. They occupy upland swales and drainage- ways where surface runoff is very slow to ponded. I'he Wenona and Rutland soils are subject to erosion. Tile drainage of the Rutland soils will help improve crojj yields in .some years. Surface and tile drainage of the Streator soils will help improve croj) yields in most years. Most areas of these soils are planted in cultivated crops, primarily com and soybeans, and they respond to good management. Various characteristics and the pro¬ ductivity indexes of the soils in association 10 are given in Table 10. Although not listed in Table 10, Peotone soils (discussed under association 9j and Rantoul soils (discussed under association 16) arc present in some parts of association 10. Soil Association 11 Plano-Proctor-Worthen Soils Soil association 11 occurs principally in the northern and central parts of Illinois but also in some of the counties near the Mississippi and Ohio rivers in southern Illinois. This as.sociation has a total area of about 1,859,- 300 acres or 5.2 ])ercent of the state’s land area. These dark-colored soils occur on nearly level to slop¬ ing glacial outwash plains and alluvial terraces. A few occur on sandy loam till or drift plains. The soils in this association fonned under grass in various thicknesses of loess or silty material over mainly stratihed silty, loamy, or sandy sediments, and range from very poorly drained to well drained. The soils of association 41 are mainly the forested counterparts of soils in association 11. A number of soil drainage sequences are present in soil association 11. The well and moderately well drained Barrington soils form a drainage sequence with the some¬ what poorly drained Mundelein soils and the poorly drained Pella soils. The main area of these three soils is extreme northeastern Illinois. All of these soils formed in loess or silty material and calcareous stratihed silty, loamy, or sandy outwash. Barrington soils, which are nearly level and gently sloping, usually occur on crests of ridges and upper parts of slopes. Mundelein soils are also nearly level and gently sloping, but arc commonly found lower on slopes than the nearby Barrington soils and on broad, nearly level areas. Pella soils are nearly level or de- pressional and are generally downslope from the other members of this drainage sequence when they are in the same landscape. Barrington and Pella soils are moderately permeable. Mundelein soils arc moderately to moderately slowly permeable. The well and moderately well drained Proctor soils form a drainage sequence with the somewhat poorly drained Brenton soils and the poorly drained Drummer soils. These soils are common throughout association 11. Soils of Illinois 23 Table 9. Characteristics and Productivity Indexes of Soil Association 9 — Catlin-Flanagan-Drummer Soils“ No. and name of soil series Slope range, % Surface soil Subsoil Sub¬ stratum Available water to 60 inches, in. Erodi- bility factor, K Productivity index*’ Avg. thick¬ ness, jn- Texture Avg. OM in plow layer, % Lime group Avg. thick¬ ness, in. Texture Natural drainage Permeability Supply of P K Texture and material High mgmt. Avg. mgmt. 171 Catlin 0-12 12 sil 3.5 B 38 sicl Well-mod. Moderate M H 1 or sicl 10.9 0.32 145 120 well till or lac. 152 Drummer 0-2 15 sici 6.0 A 33 sicl Poor Moderate L H lo ow. 11.7 0.28 150 125 154 Flanagan 0-7 17 si] 4.5 B 36 sicl SW. poor Moderate M H 1 or sicl 12.0 0.28 160 130 till or lac. 67 Harpster 0-2 15 sicl 5.5 A 24 sici Poor Moderate L L io wash 11.2 0.28 135 110 153 Pella 0-2 13 sicl 5.5 A 25 sicl Poor Moderate L M lo ow. 11.2 0.28 140 115 330 Peotone 0-2 16 sicl 6.0 A 32 sicl Poor-v. Mod. slow L M 1 or sicl till 10.2 0.28 120 100 poor ^ See abbreviations at end of Key to Iliinois Soils, page 13. ° The productivity indexes listed here 2 ipply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productiinty in Illinois, or from count) Extension and Soil Conservation Service district offices. Table 10. Characteristics and Productivity Indexes of Soil Association 10 — Wenona-Rutland-Streator Soils^ Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index^ Texture and material No. and name range, of soil series % Texture plow layer, % Lime group Texture Natural drainage Permeability Supply ot P K High mgmt. Avg. mgmt. 375 Rutland 1-5 16 sil 4.5 B 33 sicl-sic SW. poor Mod. slow-slow M H sic-c till or lac. 9.6 0.28 135 112 435 Streator 0-3 14 sicl-sic 5.5 A 34 sicl-sic Poor Mod. slow-slow L H sic< till or lac. 8.6 0.28 130 108 388 Wenona 2-15 14 sil 3.5 B 35 sicl-sic Well-mod. well Mod. slow-slow M H sic< till or lac. 8.4 0.32 125 102 ^ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Sot/ Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. They are moderately permeable, and some Proctor soils are also moderately rapidly permeable. All of these soils formed in loess or silty material and loamy outvvash. Proctor soils occur on the nearly level to strongly sloping parts of the landscape. Drummer soils on the nearly level or depressional parts, and the nearly level Brenton soils are on the intermediate parts. The well and moderately well drained Plano soils form a drainage sequence with the somewhat poorly drained Elbum soils and the Drummer soils. They are most com¬ mon in central and western Illinois, or where the loess is thicker (40 to 60 inches) than in the northeastern part of association 11. These soils formed in loess and stratified loamy glacial outwash, alluvial terraces, or sandy loam glacial till. They are moderately permeable. The nearly level to strongly sloping Plano soils occur on side slopes, crests of ridges, and wide, nearly level areas with good underdrainage. Elburn soils occur on nearly level and gently sloping parts of the landscape that are usually low'er than Plano soils. The poorly drained Drummer soils are on nearly level areas. The well and moderately well drained Raddle soils form a drainage sequence with the somewhat poorly- drained Cofifeen soils. These tw-o soils formed in silty- alluvium or colluvium typically below steep loess-covered blufifs or on alluvial terraces. They are moderately perme¬ able. Raddle soils are gently sloping or sloping and are commonly located upslope from the nearly level and gently sloping Cofifeen soils. The well and moderately well drained Worthen soils fonn a drainage sequence with the some^v-hat poorly drained Littleton soils. These soils are similar to the Raddle and Cofifeen soils, but have thicker, dark-colored surfaces. These four soils are most extensive in colluvial positions immediately below the loess blufifs of the Missis¬ sippi, Illinois, and, to a lesser extent, the Wabash River valleys. Because most of the sediment is from the thick loess bluff areas, the soils are sometimes referred to as “bluff wash” soils. The Worthen and Littleton soils are moderately permeable and have a dark upper layer more than 24 inches thick. Worthen soils are gently slop¬ ing to strongly sloping, and typically occur upslope from the nearly level and gently sloping Littleton soils. The moderately well drained Prairieville soils form a drainage sequence with the somewhat poorly drained Nachu.sa soils. These soils formed in loess and loamy ma¬ terial 1 to 3 feet thick on a partially eroded Sangamon paleosol in Illinoian till. They are most extensive in west 24 Bulletin 778 Table 11. Characteristics and Productivity Indexes of Soil Association 11 — Piano-Proctor-Worthen Soils' Surface soil Subsoil Sub- - stratum Available Productivity Avg, Avg. OM Avg. - water to Erodi- iodex^ Slope thick* in thick* Supply of Texture 60 bility - No. and name range, ness, plow layer, Lime ness, Natural - and inches, factor, High Avg. of soil series % in. Texture % group in. Texture drainage Permeability P K material in. K mgmt. mgmL 443 Barrington 0.7 12 sil 4.0 B 20 sicl-l Well-mod. well Moderate L M lo ow. 8,9 0.32 130 108 149 Brenton 0-3 15 sil 4.5 B 33 sicl-cl SW. poor Moderate L M lo ow. 11.5 0.28 150 125 136 Brooklyn 0-1 17 sil 3.0 c 36 sicl-sic Poor Slow L L lo ow. or till 10.4 0.37 105 82 347 Canisteo 0-2 18 sil-cl 5.0 A 12 cl-sl Poor Moderate L L lo ow. or till 10.0 0.28 130 105 428 Coffeen 0-4 13 sil 3.0 B 22 sil SW. poor Moderate M M sil-1 wash 10.3 0.32 145 118 764 Coyne 0-12 18 fsl 3.0 c 35 fsl-sicl Well-mod. well Rapid-mod. L L s and g ow. 9.2 0.20 105 82 152 Drummer 0-2 15 sicl 6.0 A 33 sicl Poor Moderate L M lo ow. 11.7 0.28 150 125 198 Elburn 0-5 13 sil 4.5 B 44 sicl SW. poor Moderate L M lo ow. or till 11.8 0.28 155 128 67 Harpster 0-2 15 sicl 5.5 A 24 sicl Poor Moderate L L lo wash 11.2 0.28 135 110 763 Joslin 0-6 14 sil 4.0 B 45 sil-sic Well Mod.-mod. slow M M sil lac 10.6 0.32 130 108 191 Knight 0-2 32 sil 3.5 B 33 sicl Poor Mod. slow L M lo ow. 12.4 0.32 120 98 196 Lemond 0-2 15 fsl 4.0 c 18 scl-l Poor Mod. rapid L L san. wash 7.6 0.28 110 90 81 Littleton 0-4 26 sil 3.5 B 20 sil SW. poor Moderate M M sil-1 wash 13.0 0.32 155 128 442 Mundelein 0-5 12 sil 4.5 B 26 sicl SW. poor Mod.-mod. slow L M lo ow. 10.1 0.28 135 115 649 Nachusa 0-3 1 1 sil 3.5 B 44 cl-sicl SW. poor Mod.-mod. slow M M cl paleo¬ sol 10.2 0.32 145 120 153 Pella 0-2 13 sicl 5.5 A 25 sicl Poor Moderate L M lo ow. 11.2 0.28 140 115 199 Plano 1-12 12 sil 4.0 B 40 sicl Well-mod. well Moderate M M lo ow. or tilt 11.6 0.32 145 120 650 Prairieville 0-5 12 sil 3.5 B 42 cl-sicl Mod. well Mod.-mod. slow M M cl paleo¬ sol 10.3 0.32 135 110 148 Proctor 0-15 14 sil 3.5 B 35 sicl-cl Well-mod. well Mod.-mod. rapid M H lo ow. 11.2 0.32 140 115 430 Raddle 1-8 12 sil 3.0 B 28 sil Well-mod. well Moderate M M sil-1 wash 12.4 0,32 145 118 206 Thorp 0-1 18 sit 3.5 B 32 sicl Poor Slow L L lo ow. or till 11.3 0.37 125 100 197 Troxel 0-2 32 sil 4.0 B 28 sicl Well-mod. well Moderate L M lo ow. or till 11.8 0.28 140 118 369 Waupecan 0-7 12 sil 3.5 B 38 sicl-sl Well-mod. well Moderate L M gl s-g 8.8 0.32 150 125 37 Worthen 1-12 20 sil 3.5 B 25 sil Well-mod. well Moderate M M sil-1 wash 13.0 0.32 145 120 ^ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. central Lee County and east central Whiteside County. In most areas, the paleosol was only partially eroded dur¬ ing the melting of the Wisconsinan ice, when its terminals stood in southeastern and eastern Lee and Ogle counties. When the volume of water was decreasing during the later stages of the melting of the Wisconsinan ice, erosion of the till surface ceased, and up to 3 feet of loamy ma¬ terial and loess in which the upper part of these soils formed was deposited. Brooklyn soils are poorly drained and formed in loess or silty material and loamy outwash. They are nearly level or depressional and have a clayey subsoil that is slowly penneable. Harpster soils are nearly level or slightly depressional and occur on outwash and till plains. They are moderately permeable, poorly drained, and highly calcareous throughout. The Lemond soils are similar to Harpster soils but contain more sand and less clay. Canisteo soils are also similar to Harpster soils in many respects. Even though they are calcareous, how¬ ever, they do not have as severe fertility problems as Harpster soils because they are not as high in lime. Coyne soils are nearly level to sloping and formed in sandy out¬ wash over loamy and moderately fine-textured lacustrine materials on alluvial terraces. These soils occur on terraces in the Mississippi and adjacent Rock and Green River valleys. They are well and moderately well drained. Coyne soils are rapidly permeable in the upper part and moderately permeable in the lower part. Joslin soils, which are associated with Coyne soils, are nearly level and gently sloping. The upper part of Joslin soils formed in loamy material and the lower part in clayey lacustrine sediments. Joslin soils are well drained and moderate to moderately slowly permeable. The nearly level Knight soils are in closed depressions on till plains, outwash plains, and alluvial terraces. They formed in loess and stratified loamy and sandy materials. Knight soils are poorly drained and moderately slowly permeable. Thorp soils are nearly level or depressional and occur on Soils of Illinois 25 outwash or till plains and stream terraces. These soils formed in loess or silty material and stratified loamy out¬ wash or sandy loam till. Thorp soils are poorly drained and slowly permeable. Troxel soils are nearly level, and occur in depressions or concave positions on loess-covered outwash and till plains. Troxel soils are well and moder¬ ately well drained and moderately permeable. The sur¬ face layers are over 24 inches thick. The Waupecan soils are similar to the Plano soils in many respects in the upper part of their profile. In their lower profile, however, the Waupecan soils contain more sand and gravel than the Plano soils. The major problems with the soils of this association are drainage on wet soils and erosion of sloping soils. Re¬ stricted permeability is a problem in a few areas. Most of the wet soils can be drained by tile; open inlets to the tile may be needed in a few places, especially in depressional areas. Erosion control practices are needed on the sloping areas. Most soils in this association are very productive and nearly all are cultivated; corn and soybeans are the principal crops. Various characteristics and the produc¬ tivity indexes of the soils in association 11 are given in Table 11. Soil Association 12 Saybrook-Dana-Drummer Soils Soil association 12 occurs in east central and north¬ eastern Illinois on nearly level to strongly sloping up¬ lands. It covers about 1,228,800 acres or 3.4 percent of the state’s land area. In the east central part of the state, where the loess is 40 to 60 inches thick on gently sloping, stable areas, the soils in association 12 occur on the more sloping and morainal areas, where the loess is less than 40 inches thick. These dark-colored prairie soils formed under grass vegetation and are related to the light colored forest and the moderately dark prairie-forest transition soils of association 42. The parent materials consist of loess less than 40 inches thick and the under¬ lying, medium-textured (loam) Wisconsinan-age glacial till. Sidell, Dana, and Raub soils comprise one of the three drainage sequences in this association. These soils formed in 20 to 40 inches of loess and the underlying, loam- textured glacial till. They have silty clay loam-textured subsoils, and are leached of carbonates to depths greater than 42 inches. Saybrook and Lisbon soils formed in similar parent materials but are calcareous at depths be¬ tween 24 and 42 inches. They comprise the second drainage sequence. The poorly drained Drummer soils, which are associated with both of these sequences, are underlain by medium-textured local wash. The third drainage sequence is composed of the well drained Parr, the moderately well drained Corwin and the somewhat poorly drained Odell soils. These soils formed in thinner loess (less than 15 inches), have clay loam-textured sub¬ soils, and are calcareous between 24 and 42 inches. They are most common in northeastern Illinois. Poorly drained Pella soils, which are often associated with Parr, Corwin and Odell soils, have silty clay loam, calcareous subsoils and are underlain by medium textured loamy, local wash or outwash. The minor soils in this association, among which are LaRose and Ayr, often occur in small, scattered areas. LaRose soils, which are found on the steeper slopes, formed almost entirely from calcareous glacial till. Ayr soils formed in sandy material overlying loam-textured till. LaRose and Ayr have lower available-water holding Table 12. Characteristics and Productivity Indexes of Soil Association 12 — Saybrook-Dana-Drummer Soils’ Surface soil Subsoil Sub> stratum Available Productivity Slope range, % Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. Texture and material water to 60 inches, in. Erodi- bility factor, K index° No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmt. 204 Ayr 1-10 20 si 3.0 c 20 scl Well Mod.-mod. rapid M M 1 till 8.0 0.20 120 98 495 Corwin 0-10 13 sil 4.0 B 18 sicl-cl Mod. well Mod.-mod. slow M H 1 till 9.4 0.28 135 110 56 Dana 0-6 14 sil 3.5 B 35 sicl-cl Mod. well Mod.-mod. slow M H 1 till 10.8 0.32 140 115 152 Drummer 0-2 15 sict 6.0 A 33 sicl Poor Moderate L M lo wash 11.7 0.28 150 125 60 LaRose 5-30 10 sil 3.0 c 9 cl Well-mod. well Moderate M M 1 till 7.9 0.32 125 100 59 Lisbon 0-3 14 sil 4.5 B 26 sicl-cl SW. poor Mod.-mod. slow M H 1 till 10.9 0.28 155 128 490 Odell 0-6 13 sil 4.5 B 17 sicl-cl SW. poor Mod.-mod. slow M M 1 till 9.4 0.28 145 120 221 Parr 2-18 11 sil 3.5 B 18 sicl-cl Well Moderate M H 1 till 9.2 0.32 130 105 153 Pella 0-2 13 sicl 5.5 A 25 sicl Poor Moderate L M lo wash 11.2 0.28 140 115 481 Raub 1-3 13 sil 4.5 B 38 sicl-cl SW. poor Mod. slow M H 1 till 10.9 0.28 155 128 145 Saybrook 1-12 13 sil 3.5 B 27 sicl-cl Mod. well- well Moderate M H 1 till 10.5 0.32 140 115 55 Sidell 0-12 11 sil 3.5 B 42 sicl-cl Well Moderate M H 1 till 10.9 0.32 135 110 ‘ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity Indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. 26 Bulletin 778 Table 13. Characteristics and Productivity Indexes of Soil Association 13 — Griswold-Ringwood Soils^ Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. Avg. OM Avg. stratum Erodi- bility factor, K index'’ Slope range, % SuddIv of Texture and materia] No. and name of soil series ness, in. plow layer, Texture % Lime group ness, in. Texture Natural drainage Permeability P K High mgmt. Avg. mgmt. 204 Ayr 1-10 20 si 3.0 c 20 scl Well Mod.-mod. rapid M M 1 till 8.0 0.20 120 98 363 Griswold 2-15 1 1 1 3.5 c 18 cl-sci Well Moderate M H si till 8.7 0.32 120 95 60 LaRose 5-30 10 sil 3.0 c 9 d Well-mod. well Moderate M M 1 till 7.9 0.32 125 100 297 Ringwood 0-10 15 sil 3.5 c 23 cl Mod. well- well Moderate M H sl till 10.2 0.28 ISO 105 ^ See abbreviations at end of Key to Illinois Soils, page 13. ' ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. capacities than other soils in the association. Soils in asso¬ ciation 42 are in general the forested analogues of the soils in association 12. The available-water holding capacities of soils in asso¬ ciation 12 are moderate to high except for the LaRose and Ayr soils, which tend to be droughty. Permeability is generally moderate, and tile function well in poorly drained Drummer and Pella soils. Fertility is moderate to high, and crops respond well to limestone, nitrogen, phosphorus and potassium when the need for applica¬ tions is indicated by soil tests. Soil erosion is the principal soil management problem because many areas in this association are sloping. Much of the erosion, however, can be controlled with minimum tillage, contouring, tenacing, grass waterways, and crop rotation. In the northern parts of this soil association, where livestock are common, corn, soybeans, oats, legume hay, and pasture are the major crops. Com and soybeans are the principal crops in the southern part of the association in east central Illinois. Various characteristics and the productivity indexes of the soils in association 12 are given in Table 12. Soil Association 13 Griswold-Ringwood Soils Association 13 covers a relatively small area (97,100 acres or 0.3 percent of the state’s land area) on the gently to moderately strongly sloping uplands of extreme northern Illinois, mostly in Boone, Henry, and Winne¬ bago counties. It consists of only a few soils. The two major ones, Griswold and Ringwood, formed in calcar¬ eous, sandy loam glacial till that is covered by a thin veneer of silt loam loess. These dark-colored, prairie soils formed under grass, and are considered to be the prairie counterparts of the light-colored forest soils of association 43. Griswold soils are well drained, formed in less than 15 inches of silty material over sandy loam till, and have loam or sandy loam A horizons. The texture of the per¬ meable subsoils is clay loam or sandy clay loam. Ring- wood soils are well and moderately w'ell drained, formed in 15 to 30 inches of loess over sandy loam till, and have silt loam A horizons and brownish clay loam subsoils. The minor soils in this association include LaRose and Ayr, which also occur in soil association 12. The LaRose soils, which occur on knolls and steeper slopes, formed mainly in till. The sandy Ayr soils are underlain by sandy loam till. The moderately permeable soils in association 13 have moderate available-water holding capacities and are productive. The fertility requirements of these soils are moderate, and crops respond well to limestone, nitrogen, phosphorus and potash applications when the need for these soil amendments is indicated by soil tests. The principal crops grown on these soils are com, soybeans, oats, legume hay, and pasture. Soil erosion is the major management problem on the strongly sloping areas, but it can usually be controlled with contouring, grass waterways, terraces, minimum tillage and crop rotation. Various characteristics and the productivity indexes of the soils in association 13 are given in Table 13. Soil Association 14 Varna-Elliott-Ashkum Soils Soil association 14 occurs in the upland of northeastern Illinois and occupies 983,100 acres or approximately 2.7 percent of the land area of Illinois. These dark-colored soils developed in a thin layer of loess over silty clay loam till of Wisconsinan age. The loess is generally less than 20 inches thick. The slopes of the major soils in this asso¬ ciation range from nearly level to strongly sloping. The soils developed under prairie vegetation consisting mostly of grasses such as bluestem in the genus Andropogon. The Varna-Elliott-Ashkum soils form a catena or drainage sequence of soils on the landscape. The moder¬ ately well drained Varna soils are found predominantly on sloping areas but also occur on gently sloping and Soils of Illinois 27 strongly sloping areas. The somewhat poorly drained Elliott soils occur on nearly level to gently sloping por¬ tions of the landscape at slightly higher elevations and are usually adjacent to the Ashkum soils. The poorly drained Ashkum soils occur in the lower, nearly level to depressional portion of the landscape. All three soils are fine textured and have moderately slow permeability. The Peotone soil, a significant minor soil in this asso¬ ciation, occurs as closed depressional areas that are frequently smaller than 1 acre. This dark soil is poorly to very poorly drained and has moderately slow permeabil¬ ity. Where possible, the depressional areas are usually drained by means of surface ditches or surface inlets into tile. The Wesley series is another minor soil in this associa¬ tion. It developed in 20 to 40 inches of sandy materal over silty clay loam till or silty clay loam to clay loam lacustrine materials. Wesley soils are dark colored and somewhat poorly drained. The major problems in this soil association are moder¬ ately slow permeability, inadequate amounts of phospho¬ rus in the surface soil, and susceptibility to erosion, especially on the sloping Varna soils and the upper range of the gently sloping Elliott soils. Despite their moderately slow permeability, Ashkum and Elliott soils can be drained effectively with tile. These soils are not deeply leached and weathered. Calcareous or limey, unweathered glacial till, which usually occurs at depths of less than 42 inches, tends to restrict root penetration of common farm crops to some extent and accounts for some of the fertility problems and the moderate levels of production on these soils. The rather shallow depth to the limey till makes erosion control especially important on these soils. Various characteristics and the productivity indexes of the soils in association 14 are given in Table 14. Soil Association 15 Symerton-Andres-Reddick Soils Soil association 15 occurs in northeastern Illinois, principally in DuPage, Grundy, Iroquois, Kankakee, Livingston, and Will counties. It occupies 175,200 acres or approximately 0.5 percent of the state’s land area. These dark-colored soils developed in less than 24 inches of loess on loamy outwash material over silty clay loam till or lacustrine material. The slopes of the three major soils in this association range from nearly level to sloping. These soils developed under prairie grass native vegetation. Their loess cover¬ ing varies in thickness from 0 to 24 inches, usually aver- Table 14. Characteristics and Productivity Indexes of Soil Association 14 — Varna-Elliott-Ashkum Soils^ Surface soil Subsoil Sub* Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. Stratum Available water to 60 inches, in. Erodi- bility factor, K Productivity index'’ Slope range, % Texture and material No. and name of soil series Texture plow layer, 7c Lime group Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmt. 232 Ashkum 0-3 15 sicl 6.0 A 26 sicl-sic Poor Mod. slow L H sicl till 9.6 0.28 135 110 146 Elliott 1-3 14 sil 4.5 B 22 sic-sicl SW. poor Mod. slow L H sicl till 10.2 0.28 130 102 330 Peotone 0-2 16 sicl 6.0 A 32 sicl Poor-v. poor Mod. slow L M sicl till 10.2 0.28 120 100 223 Varna 3-12 12 sil 3.5 B 18 sicl-sic Mod. well- well Mod. slow L M sicl till 10.0 0.32 125 98 141 Wesley 0-5 13 fsl 3.5 c 30 l-sici SW. poor Mod. rapid- mod. slow L M sicl lac. or till 7.1 0.24 110 88 ^ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Table 15. Characteristics and Productivity Indexes of Soil Association 15 — Symerton-Andres-Reddick Soils^ Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index^ Slope range, 7c Texture and material No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmt. 293 Andres 0-5 16 sil 4.5 B 30 sicl-cl SW. poor Mod.-mod. slow L H sicl till or lac. 11.2 0.28 145 120 594 Reddick 0-2 17 sicl 5.5 A 30 cl Poor Mod. slow L H sicl-c till or lac. 10.8 0.28 140 115 294 Symerton 0-10 15 sil 3.5 B 25 cl Mod. well- well Mod.-mod. slow L H sicl till or lac. 9.7 0.32 135 112 141 Wesley 0-5 13 fsl 3.5 C 30 l-sicl SW. poor Mod. rapid- mod. slow L M sicl lac. or till 7.1 0.24 110 88 * See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. 28 Bulletin 778 aging about 12 inches. The second parent material, loamy outwash, occurs below the surficial loess, and is from 20 to 40 inches thick. The third parent material, silty clay loam till, is 30 to 50 inches below the surface. The Symerton-Andres-Reddick soils form a drainage sequence of soils on the landscape; that is, they vary in natural drainage class and slope. The well-drained Symer- ton soils occur on gently sloping to sloping areas. The somewhat poorly drained Andres soils are found on nearly level to gently sloping portions of the landscape and frequently lie adjacent to the Reddick soils. The poorly drained Reddick soils occur in the lower, nearly level to depressional part of the landscape. Andres and Symerton soils have moderate to moderately slow perme¬ ability and Reddick soils are moderately slow in per¬ meability. The minor Wesley soils are also included in this asso¬ ciation. They are dark colored and developed from 20 to 40 inches of sandy outwash over silty clay loam till or silty clay loam to clay loam lacustrine materials. The Wesley soils differ from the Andres soils in being more sandy in the surface and subsoil portions of the soil profile. The permeability of the Wesley soils is moder¬ ately rapid in the upper 40 inches and moderately slow in the material below. The major problems with these soils are maintaining normal fertility, providing adequate tile drainage for the Reddick soils, and susceptibility to erosion, especially on the sloping Symerton soils. The soils in association 15 are somewhat thicker to the underlying silty clay loam till or lacustrine material than are the soils of association 14, Varna, Elliott and Ashkum, and as a consequence, are slightly more productive. Various characteristics and the productivity indexes of the soils in association 15 are given in Table 15. Soil Association 16 Swygert-Bryce-Mokena Soils Soil association 16 occurs in the upland of north¬ eastern Illinois and occupies 528,400 acres or approxi¬ mately 1.5 percent of the state’s land area. It occurs principally in Vermilion, Champaign, Iroquois, Ford, Livingston, LaSalle, Grundy, and Kendall counties. These dark-colored soils developed under grass in a thin layer of loess (up to 20 inches thick) on silty clay till or lacustrine sediments of Wisconsinan glacial age. Because Swygert and Bryce, the major soils in this association, form a drainage sequence on the landscape, they vary in drainage class and slope. The somewhat poorly drained Swygert soils occur on nearly level to sloping portions of the landscape at slightly higher eleva¬ tions than the Bryce soils and usually lie adjacent to them. The poorly drained Bryce soils occur in the lower, nearly level to depressional portion of the landscape. Permeability is slow in the solum surface and subsoil and very slow in the substratum. Mona, Mokena, and Reddick soils also form a drain¬ age sequence in this association. They developed in thin loess and loamy outwash 30 to 50 inches thick over silty clay or clay till or lacustrine material. They are dark colored, with moderately slow to slow permeability. The more sloping Mona soils are usually moderately well drained but are occasionally well drained. The gently sloping Mokena soils are somewhat poorly drained, and the nearly level Reddick soils are poorly drained. These soils are similar in many respects to the Symerton, Andres, and Reddick soils of association 15. The prin¬ cipal difference between them is that the underlying till or lacustrine material of the soils in association 16 is silty clay or clay rather than silty clay loam. Table 16. Characteristics and Productivity Indexes of Soil Association 16 — Swygert-Bryce-Mokena Soils^ Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in- Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index^ Slope range, % Texture and material No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability Supply ot P K High mgmt. Avg. mgmt. 235 Bryce 0-3 13 sic 6.0 A 25 sic Poor Slow L M sic till or lac. 6.3 0.28 120 98 295 Mokena 0-5 13 sil 4.5 B 25 cl-sic SW. poor Mod. slow-slow M H sic< till or lac. 9.3 0.28 125 100 448 Mona 0-10 10 sil 4.0 B 25 cl-sic Well-mod. well Mod. slow M H sic-c till or lac. 9.0 0.28 115 90 229 Monee 0-2 14 sil 3.0 B 20 sic-c Poor V. slow L M sic-c till or lac. 8.7 0.37 90 70 42 Papineau 0-3 13 fsl 3.0 c 24 scl< SW. poor Mod.-slow L M sic< till or lac. 8.0 0.20 95 75 238 Rantoul 0-1 17 sic 6.0 A 30 sic Poor-v. poor V. slow L M sic-c till or lac. 7.5 0.28 100 80 594 Reddick 0-2 17 sici 5.5 A 30 cl Poor Mod. slow L H sicl< till or lac. 10.8 0.28 140 115 91 Swygert 1-7 12 sicl 4.0 A 24 sic SW. poor Slow L H sic till or lac. 6.5 0.43 115 90 ^ See abbreviations at end of Key to Illinois Soils, 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productwity in Illinois, or from county Extension and Soil Conservation Service distria offices. Soils of Illinois 29 Table 17. Characteristics and Productivity Indexes of Soil Association 17 — Clarence-Rowe Soils’ Surface soil Subsoil Sub¬ stratum Available Productivity Avg. Avg. OM Avg. Erodi- water to index*’ Slope Texture thick- in thick- 60 bility Supply of High Avg. No. and name range, ness. plow layer, Lime ness, Natural and inches, factor, of soil series % in. Texture % group in. Texture drainage Permeability P K material in. K mgmt. mgmt. 147 Clarence 1-12 11 sici 3.5 A 20 c SW. poor V. slow L H c till or lac. 5.4 0.28 105 80 295 Mokena 0-5 13 sil 4.5 B 25 cl-sic SW. poor Mod. slow-slow M H c-sic till or lac. 9.3 0.28 125 100 448 Mona 0-10 10 sil 4.0 B 25 cl-sic Well-mod. well Mod. slow M H c-sic till or lac. 9.0 0.28 115 90 229 Monee 0-2 14 sil 3.0 B 20 c-sic Poor V. slow L M c-sic till or lac. 8.7 0.37 90 70 42 Papineau 0-3 13 fsl 3.0 c 24 scl-c SW. poor Mod.-slow L M c-sic till or lac. 8.0 0.20 95 75 238 Rantoul 0-1 17 sic 6.0 A 30 sic Poor-v. poor V. slow L M c-sic till or lac. 7.5 0.28 100 80 594 Reddick 0-2 17 sicl 5.5 A 30 cl Poor Mod. slow L H sicl< till or lac. 10.8 0.28 140 115 230 Rowe 0-2 14 sic 5.0 A 18 c Poor V. slow L M c till or lac. 5.4 0.28 110 85 ‘ See abbreviations at end of Key to IllinoU Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Other minor soils in this association are Rantoul, Monee, and Papineau. The Rantoul soils are dark and very poorly drained and occur in closed depressions that are frequently smaller than 1 acre. These very slowly permeable soils can often be drained satisfactorily with open tile inlets. Monee soils, which cover only a very small area, are moderately dark colored to light colored and pK>orly drained, with very slow permeability. They are less extensive in this soil association than in soil asso¬ ciation 17, occurring most frequently in very slight de¬ pressions in the upland portion of the landscape. The Papineau soils, which also cover a relatively small area, developed in 20 to 40 inches of loamy material over silty clay or clay till or lacustrine material. They are dark colored and somewhat poorly drained, with moderately slow permeability in the upper loamy part of the profile and very slow permeability in the lower part. The major problem in this soil association is slow permeability, which limits the usefulness of tile and in¬ hibits erosion control on the sloping Swygert and Mona soils. On the Rantoul and Monee soils, depressions can be drained by means of open tile drains. On the poorly drained Bryce soils, however, tile drains are of question¬ able value because they must often be spaced too close together to be economical. Erosion control measures such as terracing are difficult to apply to soils in this association because short slopes and depressions are often intermingled on the landscape. However, erosion can be controlled by means of conservation tillage. Because of the shallow depth to the unweathered, calcareous till, rooting of farm crops such as com and soybeans is re¬ stricted and yield reductions are common, especially in dry years. Another result of the shallow depth to un¬ weathered till is that yield reductions caused by erosion are greater and are more permanent than on more per¬ meable soils. Various characteristics and the productivity indexes of the soils in association 16 are given in Table 16. Soil Association 17 Clarence-Rowe Soils Soil association 17 occurs in the upland of north¬ eastern Illinois and occupies 116,200 acres or 0.3 percent of the state’s land area of the state. This association occurs principally in Vermilion, Ford, Iroquois, and Livingston counties. The soils are dark colored and de¬ veloped under grass in less than 20 inches of loess on clay till or lacustrine sediments of Wisconsinan glacial age. The Clarence and Rowe soils form a drainage sequence. The somewhat poorly drained Clarence soils occur on nearly level to sloping parts of the landscap>e at slightly higher elevations and are usually adjacent to the Rowe soils. The poorly drained Rowe soils occur on nearly level to occasionally depressional portions of the landscape. Permeability is very slow in both soils. Mona, Mokena, and Reddick soils are developed in thin loess and loamy outwzish 30 to 50 inches thick over silty clay or clay till or over lacustrine material. Mona soils, which are moderately well drained and well drained, occur on the more sloping areas. Mokena soils are some¬ what poorly drained and occur on gentle slopes. Poorly drained Reddick soils are nearly level and have moder¬ ately slow to slow permeability. Their underlying mate¬ rial (silty clay or clay) is finer textured than that of the Symerton and Andres soils of association 15. 30 Bulletin 778 Other soils in association 17 that cover fairly small areas are Monee, Rantoul, and Papineau. The Rantoul soils are dark and very poorly drained, and are usually found in closed depressions that are frequently smaller than 1 acre. These very slowly permeable soils can often be drained satisfactorily with open tile inlets. Monee soils are moderately dark to light colored and poorly drained, with very slow permeability. These soils occur most frequently in slight depressions. The Papineau soils in association 17 are developed in 20 to 40 inches of loamy material over clay till or lacustrine material. They are dark colored and somewhat poorly drained, with moder¬ ately slow permeability in the upper loamy part of the profile and very slow permeability in the lower part. A major problem in this soil association is slow to very slow penneability. It severely limits the use of tile in most of the soils (except Mona, which does not require drain¬ age) and hinders erosion control on the sloping Clarence and Mona soils. Tile do not function adequately in Rowe and Clarence soils, but depressions of Rantoul and Monee soils can be drained with open tile inlets. Erosion control measures such as terracing are difficult to apply to soils in this association because short slopes and depres¬ sions are often intermingled on the landscape. However, erosion can be controlled through conservation tillage. Because of the shallow depths to the unweathered clay till, the rooting depth of crops such as com and soybeans is severely restricted and yields are modest even in years of good weather. Erosion further reduces the depth to the unweathered clay till, greatly decreasing crop yields. It is difficult to renovate or reclaim the severely eroded areas because of the unfavorable nature of the under¬ lying clay till or lacustrine material. Various charac¬ teristics and the productivity indexes of the soils in association 17 are given in Table 17. Soil Association 18 Harco-Patton-Montgomery Soils Soil association 18 occurs in southeastern Illinois, primarily in the counties along the Wabash River. Most areas of these soils are relatively small; they occupy about 111,000 acres or 0.3 percent of the state’s land area. These dark-colored soils developed mainly in silty and clayey lacustrine (lakebed) sediments. A thin loess cover is present in some areas. The sediments were de¬ posited for the most part in side valleys along the Wabash River valley during the melting of the Wiscon- sinan glaciers, which extended only into the upper reaches of the Wabash River watershed. The melting of the Wisconsinan ice caused extreme flooding in the Wabash River valley, backing up water as much as 30 to 40 miles into some of the side valleys. After the glacial meltwaters receded, the side streams reestablished their channels, and their bottomlands were cut down in the lacustrine deposits, leaving the lakebed areas as terraces or benches intermediate in elevation between the uplands and bottomlands. Before being cultivated, these soils had grass or a swamp-type cover of mixed grass and trees, especially in the low-lying, poorly drained areas. The trees did not produce light-colored surface soils. Most areas of this association are nearly level, and are often intermingled with or near the light-colored, forested soils of soil association 46. Harcon and Patton soils are moderately permeable, and can be drained effectively by tiling systems if suitable outlets are available. Deep ditches are often used for tile outlets. These two highly productive soils are commonly planted in corn, soybeans, or wheat. The main problems with them are drainage and maintenance of fertility, neither of which is difficult to solve. Montgomery soils are finer textured than Harco and Patton. They are slowly to very slowly permeable, and usually must be drained by means of open ditches; tile do not function adequately in them unless spaced unusually close. Mont¬ gomery soils are moderately productive under a high level of management. Because the soils in this association are nearly level, they seldom have erosion problems. They respond to good management, and the Harco and Patton soils are among the most productive in the southern part of the state. Various characteristics and the productivity indexes of the soils in association 18 are given in Table 18. Soil Association 19 Martin ton-Milford Soils Soil association 19 occurs mainly in east central and northeastern Illinois; there are a few areas in north¬ western Illinois in the Green River lowlands, especially in northern Henry County. Most areas are located in old glacial lakebeds formed by glacial moraines or other ob¬ structions to natural drainage such as valley fills. This association occupies about 338,600 acres or 1.0 percent of the state’s land area. The largest areas of these lacustrine soils occur in Douglas, Iroquois, eastern Cook, and northern Henry counties. With the exception of Coyne, which is in part sandy, these soils formed in lacustrine sediments of silt loam, silty clay loam, silty clay, or clay texture. A thin loess cover is present in some areas. The substratum layers are generally lower in clay and higher in sand and silt than the subsoils. However, the very fine-textured Aholt and Booker soils, which are most extensive in northern Henry County, are usually very high in clay throughout their profiles. All of these soils formed under grass and are Soils of Illinois 31 Table 18. Characteristics and Productivity Indexes of Soil Association 18 — Harco-Patton-Montgomery Soils' No. and name of soil series Slope range, % Surface soil Subsoil Sub¬ stratum Available water to 60 inches, in. Erodi- bility factor, K Productivity index^ Avg. thick¬ ness, in. Texture Avg. OM in plow layer, % Lime group Avg. thick¬ ness, in. Texture Natural drainage Permeability Supply of P K Texture and material High mgmt. Avg. mgmt. 484 Harco 0-3 14 sil 4.0 B 25 sicl- SW. poor Moderate L M sil lac. 12.4 0.32 150 125 465 Montgomery 0-1 15 sic-sicl 4.0 A 23 sic Poor Slow-v. slow L M sicl-sic lac. 10.0 0.37 115 92 142 Patton 0-2 15 sic! 4.0 A 22 sicl Poor Mod.-mod. slow L M sicl-sil lac. 12.1 0.28 145 120 ^ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Table 19. Characteristics and Productivity Indexes of Soil Association 19 — Martinton-Milford Soils^ Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index‘> Slope range, % Texture and material No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmt. 670 Aholt 0-2 16 sic-c 4.0 A 35 sic-c Poor Very slow L M sicl-c lac. 6.4 0.28 75 60 457 Booker 0-2 16 sic-c 4.0 A 30 sic< Poor-v. Very slow L M sicl-c lac. 6.3 0.28 80 65 764 Coyne 0-12 18 fsl 3.0 C 35 fsl-sicl poor Well-mod. Rapid-Mod. L L s & g ow. 9.2 0.20 105 82 262 Denrock 0-2 13 sil 4.0 B 35 sic-cl well SW. poor V. slow- H M sl-s ow. 9.2 0.37 110 88 763 Joslin 0-6 14 sil 4.0 B 45 sil-sic Well mod. slow Mod.-mod. slow M M sil lac. 10.6 0.32 130 108 189 Martinton 0-5 15 sil-sicl 4.5 B 30 sicl-sic SW. poor Mod. slow L M sil-sicl lac. 10.7 0.32 135 110 69 Milford 0-2 16 sicl 5.5 A 30 sicl-sic Poor Mod. slow L M sicl-cl lac. 9.9 0.28 135 112 465 Mont- 0-1 15 sic-sicl 4.0 A 23 sic Poor Slow-v. slow L M sicl-sic lac. 10.0 0.37 115 92 gomery 141 Wesley 0-5 13 fsl 3.5 c 30 1 -sicl SW. poor Mod. rapid- L M sicl lac. 7.1 0.24 110 88 mod. slow or till ‘ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. dark colored. The light-colored, forest soil counterparts of these soils are in association 46. Most of the soils in this association are nearly level. The larger lake plains often appear as wide, flat expanses. The sandy Coyne and the silty Joslin and Denrock soils, which contain sandy and silty outwash layers as well as heavier lacustrine horizons, occur on low ridges in the lake plain. The major problems on all of these soils except the Coyne and Joslin are drainage and maintenance of fertility. The Coyne and Joslin soils do' not require drain¬ age improvement, and are often subject to erosion, espe¬ cially on their more sloping portions. The somewhat jxx)rly drained Martinton and the poorly drained Milford soils, which are extensive on many of the nearly flat lake- beds, can be tile drained, although tile draw a bit slowly in these soils. Areas of these soils are often traversed by deep ditches that serve as tile outlets. The Aholt, Booker, Montgomery, and Denrock soils are too heavy textured and too impermeable in their subsoils to be tiled satis¬ factorily. Where suitable grades can be developed, these soils are commonly drained by shallow open ditches emptying into deeper ditches. Improvement and maintenance of the fertility of these soils should be based upon soil tests. Fertility require¬ ments for good crop yields are moderate, although phos¬ phorus supplying power is generally low. Many areas of these soils are fall plowed, especially the flatter areas that tend to be wet in the spring. In general, these soils are moderately to highly productive under high manage¬ ment. Corn and soybeans are the main crops grown in this soil association. Various characteristics and the pro¬ ductivity indexes of the soils in association 19 are given in Table 19. Soil Association 20 Lorenzo-Warsaw-Wea Soils Soil association 20 occurs primarily on stream terraces or outwash areas along the state’s major streams, which carried the meltwaters of the Wisconsinan glaciers as they receded from northeastern Illinois. In the Rock River watershed, the main areas of these soils occur in Winnebago, Boone, Ogle, and western McHenry counties. In the Fox River drainage, they are most extensive in eastern McHenry, northwestern Cook, western Du Page, 32 Bulletin 778 and Kane counties. Several large areas are located in western Will County between the Du Page and the Des Plaines rivers. In the Illinois River valley, the larger areas occur in Marshall and Putnam counties. The other major areas lie in the Wabash River valley in Lawrence, Crawford, and Clark counties. Some of these soils also occur along many smaller streams such as Sugar Creek in southeastern Iroquois County. This association occupies 237,500 acres or 0.7 percent of the state’s land area. The soils of association 20 are dark colored and formed under grass in thin loamy or silty materials on sandy and gravelly outwash deposits. The light-colored forest soils that formed in materials similar to the ones in which these soils formed are in association 48. In most of the soils in association 20, the depth to the loose sand and gravel ranges from 20 to 40 inches. In a few, however, such as the Rodman, Stockland, Burkhardt, Saude, and Lorenzo soils, the loose sand and gravel occur at shallower depths of about 20 inches. In the Wea, Crane, and Westland soils, the depth to sand and gravel is somewhat more than 40 inches. Most of these soils have moderately to moderately rapidly permeable subsoils and are well or excessively drained. However, a few, such as the Fieldon, Marshan, Westland, and Will soils, are poorly drained largely be¬ cause they occur in low areas that have high water tables and not because of slowly permeable subsoils. In these naturally poorly drained areas, water tables are often lowered by means of open ditches. Water-table manage¬ ment is feasible in some areas of this association. During early spring, ditches are left open for drainage of low areas. Later in the season, as regional water tables drop, the ditches are closed off by gates to slow the rate at which the water table is lowered. The soils in this association generally have only moder¬ ate to low water-holding capacity in the upper loamy materials and very low capacity in the underlying sand and gravel. The more sandy soils’ rather low capacity to hold plant nutrients often makes it necessary to add fertilizer to meet the immediate needs of the growing crop. Another consequence of these soils’ low clay con¬ tent, their attendant relatively low nutrient and water¬ holding capacities, and their moderate to rapid perme¬ ability is that the groundwater of these soils may well become polluted if they are used for waste disposal — as septic tank absorption fields, for example. Table 20. Characteristics and Productivity Indexes of Soil Association 20 — Lorenzo-Warsaw-Wea Soils' Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K : b Slope range, % SuddIv of Texture and material No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability p K High mgmU Avg. mgmt. 961 Burkhardt 0-30 10 sl 3.0 c 10 sl-l Well Mod. rapid- rapid M M s and g ow. 4.1 0.20 75 60 286 Carmi 0-12 16 si 2.5 c 32 sl-l Well Mod. rapid- rapid M M s and g ow. 7.7 0.20 105 88 609 Crane 0-3 12 sil 4.0 B 45 sicl-cl SW. poor Mod. slow-mod. M M s and g ow. 10.8 0.32 140 118 379 Dakota 0-18 10 1 2.5 C 30 l-sl Well Mod.-mod. rapid M M s and g ow. 7.6 0.28 110 90 380 Fieldon 0-1 14 1 4.0 C 20 tsl-vtsl Poor Mod-mod. rapid L L s and g ow. 6.9 0.28 85 68 783 Flagler 0-9 18 sl 2.5 C 22 sl Well Mod. rapid- rapid M M s and g ow. 5.6 0.20 90 72 354 Hononegah 0-25 18 s 2.0 D 18 s Well Very rapid M M s and g ow. 2.3 0.15 75 60 343 Kane 0-3 14 sil 4.0 B 24 sicl-cl SW. poor Mod.-rapid M M s and g ow. 8.2 0.28 125 102 647 Lawler 0-5 16 1 3.5 c 26 1 -scl SW. poor Mod.-rapid M M s ard g ow. 7.9 0.28 115 95 318 Lorenzo 1-12 8 1 3.0 c 8 1 -cl Well Mod. rapid- rapid M M s and g ow. 4.4 0.28 90 75 772 Marshan 0-2 14 1 5.0 c 26 sicled soil material as fast as it formed. Hickory soils, which formed in Illinoian glacial till are present on the lower portion of some steep slopes. Blair soils, which occur near Hickory soils, are less well drained than Hickory but are loamy. They are also derived, at least in part, from till. The Sylvan, Iona, Reesville, and Whitson soils form a drainage sequence in which the depth to calcareous loess is shallow. All these soils have moderately developed silty clay loam subsoils. The well-drained Sylvan soils are common in associations 32 and 33, as well as in association 31. The moderately well drained Iona, somewhat poorly drained Reesville, and poorly drained Whitson soils are most common in association 33 along the Wabash River valley. The loess soils of association 31 are silty, have high water-holding capacities, and except for the calcareous Hamburg and Bold soils are productive for most crops where the slopes are not too steep. On the sloping areas, erosion control is a major problem. Steep areas, many of which are already severely eroded if they have been culti¬ vated, should be used for pasture or timber production. Fertility problems on these soils can generally be easily managed with good soil testing and soil treatment pro¬ grams. In areas where gently sloping ridgetops are nar¬ row and side slopes are moderately sloping to steep, fields are often small and irregularly shaped, making the use of large farm equipment difficult. These areas are often best suited for alfalfa or other hay crops or for pasture for livestock. Various characteristics and the productivity indexes of the soils in association 31 are given in Table 26. Soil Association 32 Fayette-Rozetta-Stronghurst Soils The Fayette, Rozetta, Stronghurst soil association occurs in northwestern and western Illinois along the valleys of the Mississippi and Illinois rivers in the upland, thick loess areas. Along the Mississippi River valley, the soils are slightly farther removed from the bluflf than the soils of association 31. Along the Illinois River valley, where the weakly developed soils of association 31 Table 25. Characteristics and Productivity Indexes of Soil Association 25 — Houghton-Palms-Muskego Soils^ Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick' ness, in. Avg. OM in plow layer, % Avg. thick¬ ness, Natural in. Texture drainage Permeability stratum Erodi- bility factor, K index>> Slope range, % SuddIv of Texture and material No. and name of soil series Texture Lime group P K High mgmt. Avg. mgmt. 777 Adrian 0-2 34 Muck 65+ E Below 34 in. (see substratum) . . L L sand 15.2 95 78 312 Edwards 0-2 32 Muck 65+ E Below 32 in. (see substratum) . . L L marl 13.1 95 78 97 Houghton 0-2 60+ Peat 65+ E . . Peat V. poor . . L L muck or peat 24.0 115 95 103 Houghton 0-2 60+ Muck 65+ E . . Muck V. poor . . L L muck or peat 24.0 125 105 210 Lena 0-2 60+ Muck 65+ E . . Muck V. poor . . L L muck or peat 24.0 120 100 638 Muskego 0-2 30 Muck 65+ E Below 30 in. (see substratum) . . L L sedimen¬ tary peat 18.3 120 100 100 Palms 0-2 35 Muck 65+ E Below 35 in. (see substratum) . . L L 1 wash 18.5 110 90 ^ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. 40 Bulletin 778 are absent, soil association 32 occurs in the bluff area adjacent to the valley. The soils of association 32 are intermediate in many respects, especially in degree of development, between the soils of associations 31 and 34, and are considered to be the light-colored counterparts of the dark-colored soils of association 2. They are also con¬ sidered to be the northern Illinois equivalent of the soils in association 33. Association 32 occupies 2,252,800 acres or 6.3 percent of the state’s land area. The major soils in this association, Fayette, Rozetta, Stronghurst, and Traer, form a drainage sequence. These four soils are well, moderately well, somewhat poorly, and poorly drained, respectively, and their internal drainage is related to the sloping to flat topography on which they occur. These soils have high amounts of avail¬ able water for crops, and are highly productive under good management. The Sylvan, Iona, Reesville, and Whitson soils form a second drainage sequence in association 32 that par¬ allels the Fayette sequence in many properties. The main difference between the two is that the second group has calcareous (limey) loess at a depth of less than 42 inches, while the Fayette sequence is more deeply leached of carbonates. The Sylvan soils are common in soil associa¬ tion 32, 33, and 34. The Iona, Reesville, and Whitson soils are most extensive in soil association 33 along the Wabash River valley. Two other extensive soils in this association are the moderately well to well drained Downs and the some¬ what poorly drained Atterberry series. Both are prairie- to-forest transitional soils, the Downs being intermediate in many resjjects between the Fayette and Rozetta and the Tama soils of association 2, and the Atterberry soils being intermediate between Stronghurst and the Musca¬ tine soils of association 2. Hamburg, one of the mi.nor soils, is composed entirely of calcareous loess, and commonly occurs as conical mounds on the immediate bluff areas along the Illinois River valley, especially in Cass and Menard counties. Bold soils are also commonly located on side slopes where erosion prevents soil development, leaving the calcareous loess exposed. The Flickory and Blair soils developed in Illinoian glacial till on sloping to very steep lower side slopes. Ursa, Atlas, Fishhook, and Elco soils developed in less than 40 inches of loess and the underlying paleosol in glacial till. They commonly occur at intermediate levels in coves and on upper side slopes. Erosion control and fertility are two of the major prob¬ lems in association 32. Any sloping soil in this area will have serious erosion problems; and because of unfavorable properties in their subsoils, the sloping or steep soils that have paleosolic influence are even more vunerable to erosion than the loess soils. Proper erosion control systems should be used on all sloping soil areas. Many of the steep, cultivated areas should be used for pasture and hay crops or for timber production. Fertility problems in this asso¬ ciation can usually be solved by proper soil testing and soil treatment programs. Various characteristics and the productivity indexes of the soils in association 32 are given in Table 27. Soil Association 33 Alford-Muren-lva Soils The soils in association 33 are light colored, having developed in loess under native trees, and occur on hilly land along major streams. The association covers a size¬ able area that extends along the east side of the Missis¬ sippi River valley from near Belleville to near Carbon- dale. Smaller areas of these soils are scattered along the west side of the Wabash and Ohio River valley between Shawneetown and the Indiana line in Clark County. Association 33 occupies 356,200 acres or 1.0 percent of the state’s land area. The major soils in this area, Alford, Muren, and Iva, form a catena or drainage sequence. The Alford soils occur on steep side slopes and narrow, rounded ridge- tops. They are well drained but must be managed care¬ fully to protect them from erosion. The Muren soils are moderately well drained and the Iva somewhat poorly drained. They occur on gently sloping ridgetops, the Iva commonly being located on the somewhat broader, more level ridgetops. The minor soils. Sylvan, Iona, Reesville, and Whitson, form a catena or drainage sequence similar to the one that includes the Alford, Muren, Iva soils, except that all four of these minor soils are calcareous within 42 inches and Whitson soils are poorly drained. The Ham¬ burg and Bold soils differ from Alford and Iona in being calcareous throughout. The Hickory and Blair soils de¬ veloped in Illinoian glacial till on sloping to very steep lower side slopes. Ursa, .\tlas, and Elco developed in loess and the underlying, moderately slowly to slowly p)erme- able glacial till paleosol. The Negley, Parke, and Pike soils are in loess and an underlying paleosol that devel¬ oped in gravelly or loamy, permeable glacial outwash material. The soils in this association are well structured, high in silt and very low in sand, and have a high capacity to store water for plants. The steeper areas (particularly of the soils, such as Negley, Ursa, and .\tlas, that have paleosols) are used primarily for timber or forage. Pro¬ duction of row crops, often in rotation with wheat and forage crops, is limited to the gently to moderately slop¬ ing areas, many of which are small and irregularly shaped Soils of Illinois 41 Table 26. Characteristics and Productivity Indexes of Soil Association 31 — Seaton-Timula Soils a Surface soil Subsoil Sub- Available water to 60 inches* in. Avg. thick- ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index^ Slope range, % Texture and material No. and name of soil series plow layer* Texture % Lime group Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmt. 5 Blair 4-25 8 sit 1.5 c 50 sicl-cl SW. poor Mod. slow L M lo. wash on till paleosol 10.6 0.37 105 80 35 Bold 5-35 7 sil 1.0 c 10 sil Well Moderate L L sil loess 12.5 0.43 70 55 30 Hamburg 7-60 4 si 1.0 c 10 si Well Moderate L L sil loess 11.5 0.43 65 50 8 Hickory 5-60 11 1 1.5 c 35 cl Well-mod. well Moderate L M 1 till lO.I 0.37 80 58 307 Iona 0-6 10 sil 2.0 c 35 sic! Mod. well Mod. slow M M sil loess 12.1 0.37 120 95 268 Mt. Carroll 1-20 13 sil 2.5 c 32 sil Weil-mod. well Moderate H H sil loess 12.9 0.32 135 110 723 Reesvillc 0-6 12 sil 2.0 c 25 sici SW. poor Mod. slow-slow L M sil loess 10.9 0.37 125 100 274 Seaton 2-45 9 sil 2.0 c 51 sil Well-mod. well Moderate H H sil loess 12.8 0.37 115 90 563 Seaton, san. sub. 2-18 10 sil 2.0 c 32 sil-1 Well-mod. well Mod.-mod. rapid M M aeolian fs 8.5 0.37 100 78 19 Sylvan 2-30 12 $11 2.0 c 18 sicl Well Moderate M M sil loess 12.5 0.37 110 85 271 Timula 5-40 12 sil 1.5 c 15 sil Well-mod. well Moderate H M sil loess 12.9 0.37 105 82 116 Whitson 0-3 11 sil 2.0 c 35 sicl Poor Mod. slow-slow M M sil loess 12.1 0.43 115 92 ^ See abbreviations at end of Key to IllinoU Soils* page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soii Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Table 27. Characteristics and Productivity Indexes of Soil Association 32 — Fayette-Rozetta-Stronghurst Soils' Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index^ Slope range, % Texture and material No. and name of soil series Texture plow layer* % Lime group Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmt. 7 Atlas 4-18 9 sil 1.5 c 60 sicl< SW. poor V. slow L L cl paleo¬ sol sil loess 7.6 0.43 55 42 61 Atterberry 0-5 15 sil 3.0 c 35 sicl SW. poor Moderate M M 12.2 0,32 140 115 5 Blair 4-25 8 sil 1.5 c 50 sicl-cl SW. poor Mod. slow L M lo wash on till paleosol 10.6 0.37 105 80 35 Bold 5-35 7 sil 1,0 c 10 sil Well Moderate L L sil loess 12.5 0.43 70 55 386 Downs 2-20 12 sil 3.0 c 40 sicl Mod. well- well Moderate H H sil loess 11.9 0.32 140 115 119 Eleo 3-18 12 sil 2.0 c 48 siclt to several feet thick is usually present between the loess and the very slowly permeable subsoil of the Sangamon paleosol. The loamy zone is a mixture of Roxana loess with the surface soil or wash of the San¬ gamon paleosol. It is thinnest on areas that were sloping and, consequently, eroding during its formation. This loamy zone is the same or very similar to the loamy layer in soil association 6, which is considered to be the prairie analogue of association 36. This extensive association occupies about 2,387,500 acres or 6.7 percent of the state’s land area. These soils formed under deciduous forest and are light colored. Although loess is from 30 tO' 55 inches on the nearly level areas, the soils on steeper slopes formed in very thin or no loess and glacial till or in paleosols that developed from the till. The moderately well drained Ava soils form a drainage sequence with the somewhat poorly drained Bluford soils and the poorly drained Wynoose soils. These soils formed in loess and the underlying Illinoian loamy soil materials or glacial till. Wynoose and Ava soils are slowly to very slowly permeable and Bluford soils are slowly perme¬ able. Wynoose has a claypan subsoil. Bluford also has high clay content in its subsoil, but its claypan is not as strongly developed as that of Wynoose. Ava has a silt pan or fragipan in its lower subsoil that limits permeability and restricts root penetration. The fragipan has high bulk density, and its structure is poorly developed. The gently sloping to strongly sloping Ava soils occur on crests of ridges or on the upper sides of drainageways. Wynoose soils are located on the edges of nearly level or flat drainage divides that border drainageways. Bluford soils, which are in a position intermediate between Ava and Wynoose soils, are nearly level or gently sloping. The somewhat poorly drained Atlas soils and moder¬ ately well drained Ursa soils formed in clayey glacial till. They are very slowly to slowly permeable, respectively, and occur in the upper parts of the sloping and strongly sloping sides of drainageways. Hickory soils are well and moderately well drained. They formed in glacial till and are moderately permeable. The sloping to very steep Hickory soils occur on the sides of valleys. The somewhat poorly drained Blair soils formed in loess, local wash, and glacial till. They are moderately slowly permeable. Blair soils are located on the sloping to moderately steep sides of drainageways. Creal soils are somewhat poorly drained and formed in loess and underlying local wash or alluvium. They are moderately slowly permeable, nearly level to gently sloping, and occur near the base of long slopes. Racoon soils are poorly drained and formed in alluvium on low terraces along streams. They are slowly permeable and nearly level or gently sloping. The well-drained Frondorf soils formed in loess and residuum from sandstone, siltstone, and shale bedrock. They are moderately permeable and occur on the sloping to very steep sides of valleys. Kell soils are moderately well drained and formed in loess, till, and residuum from bedrock. These moderately slowly permeable soils are sloping and strongly sloping and occur on the sides of drainageways. The well-drained Negley soils formed in sandy and gravelly glacial outwash. They are moderately and moderately rapidly permeable, sloping to steep, and occur on the sides of ridges and drainageways. The well- drained Parke soils formed in 20 to 40 inches of loess on reddish paleosols, which developed in sandy and gravelly outwash similar to that in the Negley soils. Parke soils are moderately permeable and occur on nearly level to steep areas. The major problems on these soils are erosion on slop¬ ing land, clayey subsoils on level land, low fertility, and low organic matter in the surface soil layer. Erosion con¬ trol should be practiced on the sloping areas. To meet the high fertility needs of these soils, it is necessary to base soil treatment upon a good testing program. Wet soils such as Wynoose must be drained by surface ditches because tile do not function in them. Steep slopes are a problem on some of these soils such as Hickory. Soils in association 36 are only moderately productive but re¬ spond well to high levels of management. Com, soybeans, wheat, hay, and milo are the main crops grown in this association. Some areas are used for pasture and others are in woodlands. Various characteristics and the pro¬ ductivity indexes of the soils in association 36 are given in Table 31. Soil Association 37 Westville-Pecatonica-Flagg Soils Soil association 37 occurs in extreme northern Illinois in Boone, Winnebago, Stephenson, Ogle, and Carroll counties, the largest area being in the northern half of Boone County. This association occupies about 127,900 acres or 0.4 percent of the state’s land area. The soils of this association have light or moderately dark-colored surface horizons, and prior to cultivation supported forest of mixed prairie-forest vegetation. They developed mainly in gently sloping to strongly sloping, upland areas. These upland areas were glaciated, and the parent materials are predominantly loam or sandy loam till of Illinoian age, with a loess cover ranging from 0 to 50 inches in thickness. Some areas developed in p>oorly 46 Bulletin 778 Table 31. Characteristics and Productivity Indexes of Soil Association 36 — Ava-Bluford-Wynoose Soils' Surface soil Subsoil Sub- Available Avg. thick* ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K rroductivity index'’ Slope range, % Supply of Texture and material No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability P K inches, in. High mgmt. Avg. mgmt. 7 Atlas 4-18 9 sil 1.5 c 60 sicl-c SW. poor Very slow L L l-cl-till 7.6 0.43 55 42 14 Ava 1-18 9 sil 1.5 c 40 sicl-sil Mod. well Slow-v, slow L M loamy wash on till pa- ieosol 10.2 0.43 105 80 5 Blair 4-25 8 sil 1.5 c 50 sicl-cl SW. poor Mod. slow L M loamy wash on till pa¬ leosol 10.6 0.37 105 80 13 Blujord 0-7 14 Ml 1.5 c 36 sicl-sic SW. poor Slow L L loamy wash on till pa¬ leosol 10.6 0.43 110 82 337 Creal 0-7 28 sil 1.5 c 22 sici SW. poor Mod. slow L M loamy wash on till pa¬ leosol 12.6 0.37 115 88 786 Frondorf 6-50 4 1 1.5 c 26 ch sicl-l Well Moderate L L ss. sis. sh. bedrock 7.0 0.32 70 55 8 Hickory 5-60 11 1 1.5 c 35 cl Mod. well- well Moderate L M 1 till lO.l 0.37 80 58 421 Kell 7-18 10 i-$ii 1.5 c 30 cl-sicl Mod. well Moderate slow L L ss. bed¬ rock 7.7 0.43 70 55 585 Negley 6-35 10 1 1.5 c 60 gl l-gl cl Well Mod. to mod. rapid L L cl ow. pa¬ leosol 6.9 0.32 105 80 15 Parke 0-35 12 sil 1.5 c 48 sicl-cl Well Moderate L L cl paleo¬ sol 10.9 0.37 115 88 109 Racoon 0-5 30 sil 1.5 c 28 sicl-sic Poor Slow L L loamy wash 11.6 0.43 115 88 605 Ursa 4-20 8 sil 1.5 c 55 cl-c Mod. well Mod. slow-slow L L cl paleo¬ sol 9.1 0.37 60 45 12 Wynoose 0-3 18 sil 1.5 c 42 c-sicl Poor Very slow L L loamy wash on till paleo¬ sol 10.0 0.43 105 78 ^ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. stratified, water-deposited sediments, and the paleosol portion of the profiles is predominantly reddish. These soils developed in the same kinds of materials as those in association 7 and are their forested counterparts. The soils of this association are all naturally well drained and have moderate permeability. Artificial drain¬ age is not needed for crop production. The Flagg, Peca- tonica, and Westville soils all have light-colored surface horizons and differ mainly in the thickness of the loess cover over the weathered, reddish drift. Flagg soils have 30 to 50 inches, Pecatonica soils 15 to 30 inches, and the Westville soils less than 15 inches of loess cover. The Myrtle and Argyle soils have moderately dark-colored surface horizons. Myrtle soils developed in 30 to 50 inches and Argyle soils developed in 15 to 30 inches of loess over drift. Much of this association is used for the production of corn, soybeans, small grains, and hay. The more strongly sloping areas, particularly of the Pecatonica and West¬ ville soils, are maintained in permanent pasture, and a few small areas are still in native forest. All of these soils respond to good management. The Westville soils tend to be somewhat drouthy during prolonged periods of dr)' weather. In order for these soils to remain productive, their fertility must be maintained. The major problem in this association is controlling erosion on the more sloping areas, where moderate erosion is common and severe erosion has occurred to some extent. Various character¬ istics and the productivity indexes of the soils in associa¬ tion 37 are given in Table 32. Soil Association 38 Middletown-Tell-Thebes Soils Soil association 38 occurs in central and northwestern Illinois in small, scattered areas. In central Illinois, it occurs mainly in Christian, Logan, Menard, and San¬ gamon counties; in northwestern Illinois, it is found in Carroll, Rock Island, Henry, Whiteside, Bureau, and Mercer counties. This association occupies about 90,400 acres or 0.3 percent of the state’s land area. The three soils in association 38 are light colored, having supported forest prior to cultivation. They de¬ veloped in less than 40 inches of loess over loamy sand or Soils of Illinois 47 sand deposits, except Middletown, which has a loess cover of 40 to 60 inches. These soils occur in upland areas and in outwash plains or on terraces, and occupy nearly level to strongly sloping landscape positions. In most areas, the underlying loamy sand to sand material is believed to have been deposited by wind. This association occurs with or near the dark-colored soils of soil association 8, which developed in the same kinds of materials. The soils of association 38 are well or moderately well drained, and all have moderate permeability. They do not require artihcial drainage. The Middletown soils are slightly more productive than the others because of their thicker loess cover and the slightly higher available-water holding capacity of their profile. Tell and Thebes soils are quite similar, except that the Tell soils have slightly weaker developed subsoils that contain less clay than the Thebes soils. The Tell soils are dominant in the areas in the northwestern part of the state, and Middletown and Thebes are the major soils in areas near the central part of Illinois. Corn, soybeans, and small grains are most commonly grown on these soils. The more sloping areas are used for hay and pasture, and a few areas support native forest. All three soils respond well to good management. The major problems are maintaining fertility and controlling erosion on the more sloping areas. Thebes and Tell soils are drouthy during periods of low rainfall. Various char¬ acteristics and the productivity indexes of the soils in association 38 are given in Table 33. Soil Association 39 Birkbeck-Sabina-Sunbury Soils Soil association 39 occurs in the north central and east central parts of Illinois. Its total area is about 454,300 acres or 1.3 percent of the state’s land area. It occurs near or with the dark-colored soils of association 9, which developed in the same kinds of materials. Except for the Hennepin soils, which developed in till on steep slopes, the soils in association 39 formed in 40 to 60 inches of loess and the underlying loamy glacial till. These nearly level to strongly sloping soils are located on upland till plains. The native vegetation of the Birkbeck, Sabina, and Hennepin soils was deciduous trees, and that of the Sunbury soils was prairie grasses and widely spaced deciduous trees. These soils have a high available-water holding capac¬ ity. The moderately well to well drained Birkbeck soils have moderate permeability. They range from nearly level to strongly sloping and occur primarily on side slopes along drainageways. They also occur on some of the upper portion of the landscape. Surface runoff is medium to rapid on these soils. The somewhat poorly drained Sabina soils have moderately slow permeability. They contain more clay in the subsoil than the Birkbeck or Sunbury soils and range from nearly level to gently sloping. They are located on higher portions of the land¬ scape. Surface runoff is medium to slow. The somewhat poorly drained Sunbury soils have moderate permeability and more organic matter and a darker surface soil than the Birkbeck or Sabina soils. They range from very gently sloping to gently sloping and occur on the higher portions of the landscape. Surface runoff is medium to slow. The well-drained Hennepin soils have moderately slow to slow permeability in the underlying material and a low available-water holding capacity. They range from strongly sloping to very steep and occur on side slopes along drainageways. Surface runoff is rapid to very rapid. These soils respond to good management, and most areas are used for cultivated crops. Tile drainage of the Sabina and Sunbury soils will help improve crop yields in some years. Fertility needs can usually be met by good soil testing and soil treatment programs. The gently to Table 32. Characteristics and Productivity Indexes of Soil Association 37 — Westville-Pecatonica-Flagg Soils^ Surface soil Subsoil Sub¬ stratum Available Productivity Avg. Avg. OM Avg. Erodi- water to index'’ Slope Texture thick- in thick- 60 bility Supply of High Avg. No. and name ranee. ness, plow layer, Lime ness, Natural and inches, factor, of soil series % in. Texture % group in. Texture drainage Permeability P K material in. K mgmt. mgmt. 227 Argyle 2-18 13 sil 3 C 47 sicl-cl Well-mod. well Moderate M H cl-sl pa- leosol 10.5 0.32 120 98 419 Flagg 0-20 11 sil 2 C 49 sicl-cl Well Moderate M H cl paleo- sol 10.8 0.37 120 98 414 Myrtle 2-18 13 sil 3 C 47 siclrly drained Kendall soils. These soils formed in 40 to 60 inches of loess and the underlying loamy outwash or sandy loam till. St. Charles soils occur on nearly level to sloping parts of the landscape, and the Kendall soils on nearly level or gently sloping parts. The well and moder¬ ately well drained Batavia soils form a drainage sequence with the somewhat poorly drained Virgil soils. These moderately dark-colored soils formed in 40 to 60 inches of loess and the underlying outwash, sandy loam till, or alluvial terrace soil materials. Batavia soils occur on nearly level and sloping parts of the landscape and are transitional between Plano and St. Charles soils. Virgil soils are located on nearly level and gently sloping areas and are transitional between Elburn and Kendall soils. Camden soils are well and moderately well drained and form a drainage sequence with the somewhat poorly drained Starks soils and the poorly drained Sexton soils. These soils formed in 24 to 40 inches of loess and loamy outwash or alluvium on outwash plains and alluvial terraces. Camden soils occur on nearly level to steep parts of the landscape, Sexton soils on the nearly level parts, and Starks soils on nearly level to gently sloping areas. The well and moderately well drained Harv'ard soils form a drainage sequence with the somewhat poorly drained Millbrook soils. These moderately dark-colored soils formed in 24 to 40 inches of loess or silty material and the underlying loamy outwash or alluvium. Harvard soils occur on nearly level to sloping parts of the land¬ scape, and Millbrook soils on nearly level and gently sloping areas. Harvard soils are transitional between Proctor and Camden soils, and Millbrook soils are transitional between Brenton and Starks soils. The well or moderately well drained Zurich soils form a drainage sequence with the somewhat poorly drained Aptakisic soils. These soils formed in 24 to 40 inches of loess or silty material over loamy or silty outwash that is calcareous (limey) at depths of less than 40 inches. Zurich soils occur on gently sloping to moderately steep parts of the landscape and are commonly above the nearly level and gently sloping Aptakisic soils. Well and moderately well drained Grays soils form a drainage sequence with the somewhat poorly drained Wauconda soils. These moderately dark-colored soils formed in 24 to 40 inches of loess or silty material over loamy or silty outwash that is calcareous at depths of less than 40 inches. Gray soils are located on gently sloping and sloping parts of the landscape and Wauconda soils on nearly level and gently sloping areas. Grays soils are transitional between Barrington and Zurich soils, and Wauconda soils are transitional between Mundelein and Aptakisic soils. The well-drained Rush soils formed in Soils of Illinois 49 30 to 50 inches of loess or silty material over sandy or gravelly outwash that is leached more than 50 inches. These soils occur on nearly level and gently sloping parts of the landscape. The well and moderately well drained Bowes soils formed in 30 to 50 inches of loess or silty ma¬ terial over gravel and sand that is leached more than 50 inches. These moderately dark soils are located on nearly level to sloping parts of the landscape and are transi¬ tional between the Rush soils and the dark-colored Waupecan soils of association 11. Drury soils are well and moderately well drained. They formed in silty col¬ luvium or alluvium on nearly level to sloping parts of the landscape, and commonly occur in colluvial positions below very thick loess bluffs, much in the same way as the Worthen and Raddle soils of association 11. The major problems on these soils are erosion on slop¬ ing land, low fertility, and low organic matter in the sur¬ face layer. Most areas of this association are cultivated primarily in corn, soybeans, wheat, and hay. A few areas are in woods. The soils in this association are productive and respond to good management. Various character¬ istics and the productivity indexes of the soils in associa¬ tion 41 are given in Table 35. Soil Association 42 Dodge-Russell-Miami Soils Soil association 42 occurs on nearly level to strongly sloping uplands in northeastern and east central Illinois and covers about 381,000 acres or 1.1 percent of the Table 34. Characteristics and Productivity Indexes of Soil Association 39 — Birkbeck-Sabina-Sunbury Soils® Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K Slope range, % Texture and material No. and name of soil series in plow layer. Texture % Lime group Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmt. 233 Birkbeck 0-12 10 sil 2 c 36 sic] Mod. well- well Moderate M H 1. sicl till or lac. 10.8 0.37 125 100 25 Hennepin 10-65 6 1 2 D 7 1 Well Mod. slow-slow M H 1 till 6.6 0.32 60 45 236 Sabina 0-5 12 sil 2 C 36 sicl SW. poor Mod. slow M H 1, sicl tilt or lac. 11.0 0.37 130 105 234 Sunbury 0-7 12 sil 3 C 35 sicl SW. poor Moderate M H t, sicl lilt or lac. 11.0 0.32 140 115 ^ See abbreviations at end of Key to Illinois Soils, page IS. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity m Illinois, or from county Extension and Soil Conservation Service district offices. Table 35. Characteristics and Productivity Indexes of Soil Association 41 — St. Charles-Camden-Drury Soils® Surface soil Subsoil Sub¬ stratum Available Productivity Avg. Avg. OM Avg. Erodi- water to index^ Slope Texture thick- in thick- 60 bility Supply of High Avg. No. and name range, ness. plow layer, Lime ness. Natural and inches, factor, of soil series % in. Texture % group in. Texture drainage Permeability P K material in. K mgmt. mgmt. 365 Apiakisic 0-5 10 sil 2.0 C 26 sicl SW. poor Moderate L M lo ow. 8,9 0.37 115 92 105 Batavia 0-12 12 sil 2.5 c 38 sic! Well-mod. well Moderate L M lo ow. or till 11.6 0.32 135 110 792 Bowes 0-10 13 sil 2.5 c 38 sicl Well-mod. well Moderate L M s-g ow. 9.2 0.32 140 118 134 Camden 0-30 12 sil 2.0 c 40 sicl-sl Well-mod. well Moderate L M lo ow. 10.8 0.37 120 95 75 Drury 1-12 12 sil 2.0 c 24 sil Well-mod. well Moderate M M sil-1 wash. 12.4 0.37 125 105 698 Grays 1-12 11 sit 2.5 c 20 sicl-1 Well-mod. well Moderate L M lo ow. 8.7 0.32 120 98 344 Harvard 0-10 11 sil 2.5 c 36 sicloor Moderate L M lo ow. 8.9 0.32 125 105 696 Zurich 1-18 9 sil 2.0 c 22 sicl-1 Well-mod. well Moderate L M lo ow. 10.2 0.37 115 90 * See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. 50 Bulletin 778 state’s land area. The largest areas of these soils are in Boone, DeKalb, Kane, Kendall and McHenry counties in the north and Clark, Coles, Cumberland, Edgar, and Shelby counties in the east central part. These light and moderately dark-colored soils formed in less than 40 inches of loess over loam-textured Wisconsinan till under forest or mixed grass and forest, and are similar to the dark-colored prairie soils of association 12. The light-colored Russell, Xenia, and Fincastle soils are well, moderately well, and somewhat poorly drained, respectively. The moderately dark-colored Mellott, Win¬ gate, and Toronto soils comprise a similar drainage sequence. All of these soils formed in 20 to 40 inches of loess over loam till, and have silty clay loam and clay loam-textured subsoils that are free of carbonates to depths below 42 inches. Mellott, Wingate, and Toronto are transitional between the Russell, Xenia, Fincastle sequence and the corresponding dark-colored Sidell, Dana, and Raub soils of association 12. Dodge and Herbert soils are similar in texture but are calcareous at depths between 24 and 42 inches. The light-colored Miami and the transitional Octagon and Montmorenci soils formed in less than 15 inches of loess on loam till and have silt loam surface horizons and clay loam tex¬ tured subsoils that become calcareous at depths between 24 and 42 inches. Strawn and Hennepin soils, which occur on steeper slopes in the association, have formed from the glacial till and are calcareous at very shallow depths. Metea soils formed from sandy materials 20 to 40 inches thick on loam till and have a fairly low available- water holding capacity. With the exception of the sandy Metea soils, these soils are moderately or moderately slowly permeable and have moderate to high available-water holding capacities. Tile can be used if needed on the somewhat poorly drained .soils. The sub.soil nutrient-supplying capacities of these soils are moderate, and crops respond well to limestone, nitrogen, phosphorus, and potassium where soils tests in¬ dicate a need for application. Soil erosion is the principal management problem on these soils. Contouring and terracing are often difficult to practice because of short, irregular slopes, but grass waterways and minimum tillage can be used in most fields. Crop rotations that include legume hay and pas¬ ture effectively reduce erosion on these soils. The prin¬ cipal crops grown on them are corn, soybeans, and legume hay. Dairy and mixed livestock farms are com¬ mon in this association in northern Illinois; much of the association’s less productive, steeper land is in pasture. Various characteristics and the productivity indexes of the soils in association 42 are given in Table 36. Soil Association 43 Kidder-McHenry Soils Soil association 43 occurs on gently to strongly sloping uplands in northeastern Illinois in Boone, Cook, Kane, McHenry, and Winnebago counties. Its total area is 65,800 acres or 0.2 percent of the state’s land area. This association is composed of only a few soils, the Kidder and McHenry soils being the major ones. Well and moderately well drained Kidder soils formed in less than 15 inches of loess and McHenry soils formed in 15 to 30 inches of loess and the underlying calcareous sandy loam till. These light-colored forest soils are similar to the prairie soils of association 13. Kidder soils generally Table 36. Characteristics and Productivity Indexes of Soil Association 42 — Dodge-Russell-Miami Soils^ Surface soil Subsoil Sub¬ stratum Available Productivity Slope range, % Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. Texture and material water to 60 inches, in. Erodi- bility factor, K index” No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability Supply ot P K High mgmt. Avg. mgmt. 24 Dodge 0-20 11 sil 2.0 c 24 sicl-cl Well Moderate M H 1 till 9.9 0.37 125 100 496 Fincastle 1-3 11 sil 2.0 c 34 sict-cl SW. poor Mod.-mod. slow M H 1 till 10.5 0.37 130 102 25 Hennepin 12-65 6 1 2.0 D 6 1 Well Mod.-mod. slow L M 1 till 6.4 0.32 60 45 62 Herbert 0-3 12 sil 3.0 c 24 sicl-cl SW. poor Moderate M H 1 till 10.0 0.32 135 110 407 Mellott 0-12 13 sil 2.5 c 44 sicl-cl Well Moderate M M 1 till 11.0 0.32 130 102 205 Metea 0-15 10 si 2.0 D 32 scl Well Mod.-rapid M L 1 till 8.7 0.17 105 82 27 Miami 0-25 12 sil 2.0 c 24 cl Well Moderate M M 1 till 9.8 0.37 120 95 57 Montmo- 0-5 11 sil 3.0 c 20 cl Mod. well Mod. slow M M 1 till 9.5 0.32 125 100 renci 656 Octagon 0-12 12 sil 3.0 c 24 cl Well Moderate M M 1 till 10.0 0.32 125 100 322 Russell 3-18 10 sil 2.0 c 38 sicl-cl Well Moderate M M 1 till 10.5 0.37 125 97 224 Strawn 5-45 7 sil 2.0 c 15 cl Well-mod. Moderate M M 1 till 8.0 0.37 105 82 353 Toronto 0-6 10 sil 3.0 c 38 sicl-cl well SW. poor Moderate M M 1 till 10.6 0.32 135 110 348 Wingate 1-6 13 sil 3.0 c 35 sicl-cl Mod. well Mod. slow M M 1 till 10.7 0.32 130 105 291 Xenia 1-5 11 sil 2.0 c 44 sicl-cl Mod. well Mod. slow M M 1 till 11.0 0.37 125 97 ^ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Soils of Illinois 51 have a silt loam A horizon and a loam, sandy clay loam, or clay loam subsoil over the glacial till. McHenry soils, which formed in thicker loess, have a silty clay loam upper subsoil. The minor soils include Strawn and Hennepin, which occur on steeper slopes and formed in calcareous loam textured glacial till. Strawn is calcareous (limey) at depths of less than 24 inches, and Hennepin is limey at less than 10 inches. Metea soils formed in sandy materials that overlie the glacial till and have fairly low available- water holding capacities. The soils in association 43 are permeable and have moderate available-water holding capacities. These soils respond well to fertilizer applications, and are moder¬ ately productive. The major crops include com, soy¬ beans, oats, forages, and pasture. Much of the association is devoted to dairy and livestock farms. Soil erosion is the chief management problem on the steeper slopes. Contouring is often difficult on the short, irregular slopes that are often present in this association, but erosion can be controlled by minimum tillage, grass waterways, and rotations that include forage crops. Various characteristics and the productivity indexes of the soils in association 43 are given in Table 37. Soil Association 44 Morley-Blount-Beecher Soils Soil association 44 occurs in the upland of north¬ eastern Illinois and occupies about 642,200 acres or ap¬ proximately 1.8 percent of the state’s land area. This soil association occurs principally in Vermilion, Champaign, Grundy, Kankakee, Will, Cook, DuPage, Lake, Mc¬ Henry, and Kane counties. Its soils are mostly light colored, although it does include two moderately dark- colored prairie-forest transition soils. The soils developed in 0 to 20 inches of loess over silty clay loam glacial till. Both the loess and glacial till are of Wisconsinan glacial age, and the soils are leached and weathered to shallow- depths, with lime at depths of less than 42 inches. Soil association 44 occurs near or with the dark-colored soils of association 14, and are considered to be their light- colored analogues. The major soils in this association range from nearly level to steep; most of the landscape is sloping to strongly sloping. The major soils, Morley, Blount, Beecher, and Markham, developed under native deciduous forest. The Morley and Blount soils form a toposequence on the landscape, with the Blount soils occupying the more level positions and the Morley soils the more sloping positions. The Blount soils are somewhat poorly drained, and the Morley soils are moderately well drained for the most part, although some are well drained. The perme¬ ability of both soils is slow to moderately slow. The Beecher and Markham soils are included in this soil association because they developed from the same kind of parent materials as the Morley and Blount soils and share the same sequence of horizons in the soil profile. They differ from the Morley-Blount soils in having darker, thicker surface horizons. The Beecher soils occur on nearly level to sloping areas and are somewhat poorly drained. They are transitional between the Blount soils and the Elliott soils of association 14. The Markham soils occur on gently sloping to moderately steep slopes, and most are moderately well drained, although some areas are well drained. These soils are transitional between the Morley soils and the Varna soils of association 14. The permeability of both soils is slow to moderately slow. The Chatsworth soils are minor in extent in this soil association. They are light colored, having developed under native deciduous forest on strongly sloping to very steep areas. Their permeability is very slow. They are moderately well drained, have relatively thin profiles, and usually have carbonates at less than 10 inches. The major problem in this soil association is soil erosion. Some erosion control measures, such as terracing. Table 37. Characteristics and Productivity Indexes of Soil Association 43 — Kidder-McHenry Soils^ Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index*> Slope range, % Texture and material No. and name of soil series plow layer, Texture % Lime group Texture Natural drainage Permeability P K High mgmt. Avg. mgmt. 25 Hennepin 12-65 6 1 2 D 6 1 Well Mod.-mod. slow L M 1 till 6.4 0.32 60 45 361 Kiddtr 0-35 7 sil 2 D 23 cl-scl Well Moderate M M si till 8.8 0.32 105 82 310 McHenry 0-12 13 sil 2 C 21 siclor Slow L M sic, c till or lac. 7.8 0,37 95 75 554 Kernan 1-5 14 sil 2 c 28 sicl-sic SW. poor Mod. slow-slow L M sic, c till or lac. 9.5 0.37 110 88 228 Nappanee 0-4 10 sil 2 c 18 c SW. poor V. slow L M sic, c till or lac. 7.4 0.43 90 68 560 St. Clair 2-45 9 sil 2 c 16 c Mod. well- well V. slow L M sic, c till or lac. 7.2 0.37 85 62 ^ See abbreviations at end of Key to Illinoii Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Soil Association 46 Markland-Colp-Del Rey Soils Soil association 46 is located primarily in the larger side valleys, the Embarras, Bonpas, Little Wabash, Skillet Fork, and Saline rivers, along the Wabash River valley in southeastern Illinois, and the Big Muddy and Kaskaskia River valleys in southwestern Illinois. Other areas of these soils occur in the Green River basin and Plum River valley in northwestern Illinois and in glacial lakebeds in Iroquois, Grundy, Cook, and Lake counties. This association occupies about 298,900 acres or 0.8 per¬ cent of the state’s land area. Soil association 46 includes light-colored soils that formed under forest in moderately fine- to fine-textured lacustrine sediments of Wisconsinan age. Except for their light-colored surfaces, these soils are comparable in many respects to the dark-colored grassland soils of associations 18 and 19, with which they normally occur and with which they share a common origin. In both the lakebeds and side valleys, quiet waters or backwaters existed long enough for fine-textured sediments to settle and form the lacustrine deposits. The Uniontown, Reesville, and Marissa soils are largely restricted to southeastern Illinois, and are not as fine-textured in their subsoils as the other soils in this association. Reesville and Marissa can usually be tile drained satisfactorily. Although Uniontown does not require drainage improvements, the other somewhat poorly and poorly drained soils in this area do benefit from improved drainage. Because these soils have slow or very slow permeability, however, tile seldom function adequately in them, and they must be drained by means of surface ditches. The Markland, McGary, Zipp, and Bungay soils are found mostly in southeastern Illinois. In general, they are less deeply leached than the Colp, Hurst, Okaw, and Wagner soils, which occur pre¬ dominantly in side valleys of the Mississippi River valley in southwestern Illinois. Niota and Zwingle soils are largely confined to side valleys of the Mississippi River valley in northwestern Illinois. The Saylesville and Del Rey soils are most extensive in glacial lakebeds in north¬ eastern Illinois. The major problems on these light-colored soils are drainage improvement on the somewhat poorly and poorly drained soils and maintenance of fertility, organic matter, and good physical condition. The more sloping Colp, Markland, Uniontown, and Saylesville soils have more problems with erosion than with drainage. The soils of this association generally require moderate to high applications of limestone and phosphorus and moderate amounts of potassium to produce high yields. Corn and wheat respond very well to nitrogen applications. Soy¬ beans are also commonly grown in this association. Some areas, particularly of Okaw soils, are in forest. Most of these soils are moderately productive under high man¬ agement, but their fine- to very fine-textured subsoils restrict underdrainage and root penetration. Various characteristics and the productivity indexes of the soils in association 46 are given in Table 40. Soil Association 48 Casco-Fox-Ockley Soils Soil association 48 occurs primarily on terrace and outwash areas along the Fox, Du Page, and Des Plaines rivers in northeastern Illinois. The larger areas are located in McHenry, western Lake, northern Cook, western DuPage, Kane, Kendall, and LaSalle counties along the Fox River and in Will County along the Du¬ Page and Des Plaines rivers. There are small, scattered areas in Winnebago, Boone, and Ogle counties along the Rock River and other streams in northern Illinois, but 54 Bulletin 778 Table 40. Characteristics and Productivity Indexes of Soil Association 46 — Markland-Colp-Del Rey Soils' Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM in plow layer, % Avg. thick¬ ness, in. stratum Erodi- bility factor, K index^ Slope range, % No. and name of soil series Texture Lime group Texture Natural drainage Permeability Supply of P K and material High mgmt. Avg. mgmt. 444 Bungay 0-2 10 sicl-sic 2.0 B 40 sic Poor Slow L M sic-sici lac. 8.9 0.32 105 82 122 Colp 1-18 11 sil 2.0 c 40 sic-sici Mod. well Slow L M sil-c lac. 9.9 0.43 90 68 192 Del Rey 0-5 10 sil 2.5 c 32 sic-sici SW. poor Slow L M sicl-sil lac. 9.9 0.43 115 92 338 Hurst 1-6 12 sil 1.5 c 32 sic SW. poor Very slow L M sicl-c lac. 9.2 0.43 90 70 176 Maris&a 0-3 16 sil 3.5 c 35 sicl SW. .poor Mod.-mod. slow L M sil-sicl lac. 11.8 0.37 135 110 467 Markland 1-35 9 sil 2.0 c 22 sic Mod. well- well Slow L M sicl-c lac. 7.6 0.43 95 72 173 McGary 0-6 10 sil 1.5 c 23 sic SW. poor SIow-v. slow L M sicl< lac. 7.8 0.43 95 72 261 Niota 0-3 12 sil 2.0 c 35 sic-sici Poor Very slow M M sil-sicl lac. 10.0 0.37 90 70 568 Niota, thin A 0-4 7 sicl 2.0 B 30 sic-sici Poor Very slow M M sil-sicl lac. 9.1 0.37 75 58 84 Okaw 0-5 10 sil 1.5 c 32 sic-sici Poor Very slow L L sicl-c lac. 8.9 0.43 85 65 723 Reesville 0-6 12 sil 2.0 c 25 sicl SW. poor Mod.-mod. slow L H sil-sicl lac. 10.9 0.37 125 100 370 Saylesville 0-20 10 sil 2.0 c 24 sicl-sic Mod. well- well Mod. slow L M sicl-sil lac. 9.8 0.37 105 85 482 Uniontown 0-12 10 sil 1.5 c 25 sicl Well-mod. well Mod.-mod. slow L H sil-sicl lac. 10.8 0.37 115 92 26 Wagner 0-3 15 sil 3.0 c 32 sic-sici Poor Very slow L L sicl lac. 10.7 0.28 105 85 524 Zipp 0-2 10 sicl 2.0 B 28 sic Poor Slow-v. slow L M sic< lac. 7.7 0.28 115 90 576 Zwingle 0-2 13 sil 1.5 c 35 sic Poor Very slow M M 1-sl ow. 8.9 0.43 95 75 ‘ See abbreviations at end of Key to Illinois Soils* page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. these land areas are too small to be shown on the General Soil Map. The soils in association 48 developed under forest in thin loamy and silty sediments over sandy and gravelly outwash. Many of these soils have profiles that are similar to those of the dark-colored prairie soils in asso¬ ciation 20, and are often considered to be the light- colored, forested counterparts of those soils. The thick¬ ness of the loamy and silty sediments over sand and gravel varies from 20 to 40 inches in most of the soils of association 48. In a few soils, such as Casco and Ston- ington, the depth to sandy and gravelly materials is only 10 to 20 inches, and in two soils, Longlois and Ockley, the depth is somewhat more than 40 inches. Generally, the soils of association 48 are well drained and moderately permeable in their subsoils. Only two soils, Homer and Matherton, are somewhat poorly drained and may benefit from improved drainage. Be¬ cause the soils of this association are gently to strongly sloping, erosion control is often needed, especially on the more sloping areas. Other problems on these soils are maintenance of fertility and organic matter in the surface soils. Because of their fairly low clay content, some of these soils do not hold large supplies of plant nutrients and water. .Application of lime and fertilizers to soils that are low in clay should be based upon the immediate needs of the crop to be grown. Improving and maintain¬ ing organic matter in the surface horizons will help these soils store more water for crops and reduce runoff and erosion. Wind erosion is sometimes a problem in dry, early springs if the soils do not have enough vegetative cover. The more sandy soils, which are lower in clay, may contribute to groundwater pollution if waste dis¬ posal systems such as septic tank absorption fields or sewage lagoons are located in them. Corn, soybeans, and wheat are the major crops grown in soil association 48. Most of the steep areas are in pasture or timber. Where the sand and gravel deposits underlying these soils are thick, they are usually good sources of well water for irrigation of corn and soybeans. These soils also have good potential for vegetable crop production where underground water supplies are suf¬ ficient for irrigation. Various characteristics and the pro¬ ductivity indexes of the soils in association 48 are given in Table 41. Soil Association 49 Martinsville-Sciotoville Soils Soil association 49 occurs primarily on the terrace areas in the Ohio and lower Wabash River valleys. There are also small, scattered areas in a number of other counties in northeastern Illinois, but many of these areas are not shown on the General Soil Map. The soils of asso- Soils of Illinois 55 ciation 49 often occur near or with the dark-colored soils of association 21 that formed in the same kind of mate¬ rials. This association occupies 101,300 acres or 0.3 per¬ cent of the state’s land area. The soils of association 49 are light colored and formed in thin silty or loamy materials on sandy, Wiscon- sinan outwash under forest. The well-drained Martins¬ ville soils and the somewhat poorly drained Whitaker soils form a drainage sequence and are among the major soils in this association in northeastern Illinois. They have sandy loam or sandy clay loam subsoils and are moderately permeable. .Another extensive drainage se¬ quence comprises the well-drained Wheeling, moderately well drained Sciotoville, somewhat poorly drained Wein- bach, and poorly drained Ginat soils. It occurs primarily in extreme southern Illinois where sediments were de¬ posited by the Ohio River. One of the larger areas is in the valley now occupied by the Cache River. These soils have silt loam surface soils but loamy subsoils that are high in mica minerals. The permeability of these soils ranges from moderate in Wheeling to very slow in Weinbach and Ginat. The moderately well drained Emma soils formed in acid silty clay loam sediments that were also deposited by the Ohio River. The well to moderately well drained Grellton soils formed in 20 to 40 inches of loamy material on 15 to 30 inches of silty ma¬ terial on sandy loam material. Most soils in this association have moderate water¬ holding capacity and are moderately productive if managed properly. Many areas have sources of water for irrigation. Erosion is a problem on sloping areas. Some wind erosion is possible on areas that are tilled or do not have enough vegetative cover in dry spring seasons. Fer¬ tility is generally low, but can be corrected if good soil testing and soil treatment programs are followed. Corn and soybeans are the main crops on these soils. Various characteristics and the productivity indexes of the soils in association 49 are given in Table 42. Soil Association 50 Oakville-Lamont-Alvin Soils Soil association 50 occurs in many counties around the state. The three major areas are in Kankakee and Mason counties and in the Green River lowland regions of Henry and Lee counties. Many small areas are found in the Wabash River valley. The soils of this association are located in areas where materials high in sand have been deposited either by wind or water from rivers or streams or glacial outwash. This association occupies about 467,700 acres or 1.3 percent of the state’s land area. These soils formed in sandy glacial outwash, sandy alluvium, or sandy aeolian material. In general, they are very sandy and occur on nearly level to very steep ter¬ races and on uplands. These light-colored soils formed under deciduous forest, except for the moderately dark- Table 41. Characteristics and Productivity Indexes of Soil Association 48 — Casco-Fox-Ockley Soils^ Surface soil Subsoil Sub¬ stratum Available Productivity No. and name of soil series Slope range, % Avg. thick¬ ness, in. Texture Avg. OM in plow layer, % Lime group Avg. thick¬ ness, in. Texture Natural drainage Permeability Supply of P K Texture and material water to 60 inches, in. Erodi- bility factor, K index'’ High Avg. mgmt. mgmt. 706 Boyer 0-40 12 Is 1.5 D 20 sl-sci Well Mod. rapid- L L s and K 5.0 0.17 85 70 rapid ow. 323 Casco 0-45 8 sll-l 2.0 C 10 1-scl Well Mod.-rapid M M s and 8 4.5 0.32 90 72 346 Dowagic 0-12 10 sil 3.0 C 40 sl-cl Well Mod.-rapid M M s and g 8.1 0.28 105 85 325 Dresden 1-10 11 sil 3.0 C 24 sicl-cl Well Mod.-mod. M M s and g 7.6 0.28 110 88 rapid ow. 137 Ellison 0-10 11 sil 2.0 C 30 sicl-cl Well Mod.-mod. M M s and g 7.3 0.32 105 82 rapid ow. 327 Fox 1-30 10 sil 2.0 C 22 sicl-cl Well Mod.-mod. M M s and g 6.9 0.32 105 82 rapid ow. 771 Mayfield 0-3 12 1 3.0 C 28 l-cl Mod. well Mod.-rapid M M s and g 8.3 0.32 105 85 SW. poor ow. 326 Homer 0-6 10 sil 2.0 C 22 sicl-cl SW. poor Mod.-rapid M M $ and g 7.1 0.37 115 92 394 Longlois 1-6 12 sil 3.0 c 45 sicl-cl Well Mod.-rapid M M s and g 11.0 0.37 130 115 342 Matherton 0-6 11 sil 3.0 c 24 scl-cl SW. poor Mod.-rapid M M s and ow. g 7.4 0.28 120 98 387 Ockley 1-18 12 sil 2.0 c 45 cl-sici Well Mod.-rapid M M s and g 11.0 0.37 125 105 253 Stonington 5-30 9 l-sl 1.5 D 15 l-sl Well Mod.-rapid L L s and g 4.7 0.24 75 60 ow. ^ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. 56 Bulletin 778 colored Billett soils, which developed under prairie grasses and widely scattered deciduous trees. Many of the soils in association 50 are the forested counterparts of the dark-colored, sandy soils of association 22. The soils of this association typically have a moderate to low available-water holding capacity. Two exceptions are the poorly drained Ruark and moderately well to well drained, thick A Alvin soils, which have a high available-water holding capacity. Permeability is rapid or very rapid in the subsoil or substratum of all the soils in this association, except for the Roby, which has moderate to moderately rapid permeability in the sub¬ soil, and the Ruark soils, which have moderately slow to moderate permeability. Surface runoff ranges from very slow to medium. The poorly drained Ruark and some¬ what poorly drained Roby soils form a drainage sequence with the well and moderately well drained Alvin soils. The Alvin, Bloomfield, Chelsea, Chute, Lamont, Oak¬ ville and Plainfield soils are nearly level to very steep and formed in aeolian sand and sandy loams. These soils range from excessively drained to well drained, and the depth to water table is greater than 6 feet. Some areas of the Alvin soils in Alexander County have a thicker sur¬ face soil than is typical (Alvin, thick A variant). The very gently sloping to moderately steep, well-drained Billett soils formed in sandy loam alluvium or glacial outwash. The nearly level to gently sloping, somewhat poorly drained Morocco soils are formed in sandy or sandy loam glacial outwash or alluvium. The depth to water table is 1 to 3 feet. Erosion and drouthiness are the main problems with these soils. Wind erosion is frequently a problem in the spring when the soil surface is unprotected. In some areas there is also some erosion by runoff. These soils are drouthy for crops such as corn and soybeans in the late summer when there is a normal or less than normal amount of rainfall. The Ruark soils are the only soils in this association that need drainage. Surface and sub¬ surface drainage will improve yields on Ruark, although there may be problems if tile are laid in the sandy sub¬ stratum. Except for the Roby and Ruark soils, these soils are poor filters for sewage disposal systems. If the soils are used for that purpose, the ground water may become contaminated because of the low clay content in their subsoils and consequent rapid permeability. Another re¬ sult of the rapid permeability is that these soils do not hold plant nutrients well and usually require fertilization for the crop being grown. Soil treatments must sometimes be applied in smaller amounts but with more frequency than in soils with higher water- and nutrient-holding capacities. Most areas of these soils are used for cultivated crops. Some areas have trees growing on them, and the more sloping ones are used for pasture. Some areas are irri¬ gated; many are good sources of water from wells. The characteristics and the productivity indexes of the soil in association 50 are given in Table 43. Soil Association 51 Ritchey-New Glarus-Pclsgrove Soils Soil association 51 occurs in northwestern Illinois and in Kankakee County in the northeastern part of the state. It often occurs with or near the dark-colored soils of association 23, which formed in similar kinds of ma¬ terials. The soils in this association developed under forest vegetation and are light colored except for the moderately dark-colored Oneco, Nassett, and Backbone soils, which formed under mixed grass and scattered trees. This association occupies about 205,700 acres or 0.6 per¬ cent of the state’s land area. The soils of this association developed in silty or loamy material (loess, till, or outwash) with or without residuum on limestone at depths ranging from about 10 to more than 60 inches. In some areas in northwestern Illinois, the clayey residuum is very thick (greater than 60 inches) ; in others, especially in northeastern Illinois, it is absent because of erosion that occurred before the silty loess or loamy material was deposited. All of these soils are well drained and moderately per¬ meable except Oneco, which is well and moderately well drained, and New Glams, which has moderate to moder¬ ately slow permeability. Available-water holding capacity is low in those soils that have limestone at depths of less than 20 inches, such as Ritchey, Dunbarton, and Dun- barton-cherty, and moderate in those with limestone at depths approaching 40 or more inches. Because these soils limit root penetration and are low in available-water holding capacity, crop yields on them are low to moderate. All of these soils tend to be sloping. As a re¬ sult, erosion is a serious problem in many areas because it further reduces the thickness of the already thin root¬ ing medium. Various properties and the productivity indexes of the soils in association 51 are given in Table 44. Soils of Illinois 57 Table 42. Characteristics and Productivity Indexes of Soil Association 49 — Martinsville-Sciotoville Soils^ Surface soil Subsoil Sub¬ stratum Available Productivity Slope range, % Avg. thick¬ ness, in. Avg. OM Avg. thick- ness, in. Texture and material water to 60 inches, in. Erodi- bility factor, K index^ No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmt. 469 Emma 0-12 8 sicl 2.0 B 48 sicl Mod. well Mod. slow M L acid sicl 11.0 0.37 110 90 460 Ginat 0-2 9 sil 1.5 c 48 sicl Poor V. slow L L acid sicl 8.9 0.43 105 82 780 Grcllton 0-20 5 s) 2.0 D 42 sil-fsl Well-mod. well Moderate M M sl-sil till 10.5 0.24 105 82 570 Martinsi'iUf 1-18 12 sil 2.0 C 36 cl-sici Well Moderate M M sl-scl ow. 10.0 0.37 115 92 462 Sciotoville 0-12 10 sil 2.0 C 44 sicl-sil Mod. well Mod. slow L M sl-1 ow. 9.3 0.37 105 82 461 Weinbach 0-5 15 sil 2.0 C 39 sicl-sil SW. poor V. slow L M sicl-sl ow. 10.4 0.43 115 90 463 Wheeling 0-5 14 sil 2.0 C 36 sicl-fsl Well Moderate L M si, s ow. 7.6 0.32 105 82 571 Whitaker 0-6 12 sil 2.0 C 36 cl-l SW. poor Moderate M M si. sil ow. 10.7 0.37 120 90 * See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productiinty in Illinois, or from county Extension and Soil Conservation Service district oflfices. Table 43. Characteristics and Productivity Indexes of Soil Association 50 — Oakville-Lamont-Alvin Soils^ Surface soil Subsoil Sub¬ stratum Available Productivity Avg. Avg. OM Avg. Erodi- water to index*’ Slope Supply of Texture thick- in thick- 60 bility No. and name range. ness. plow layer. Lime ness. Natural and inches. factor. High Avg. of soil series % in. Texture % group in. Texture drainage Permeability P K material in. K mgmt. mgmt. 131 Alvin 1-30 18 fsl 1.0 D 26 l-sl Well-mod. well Mod.-mod. rapid L L fs ow. 8e aeolian 8.4 0.24 105 85 131V Alvin, thick A 0-4 28 fsl 1.0 D 22 1-scl Well-mod. well Mod.-mod. rapid L L fs ow. &: aeolian 9.0 0.24 110 90 332 Billett 0-20 8 sl 1.5 D 47 si V7ell Mod. rapid- rapid L L s ow. 8c aeolian 7.6 0.20 90 72 53 Bloomfield 1-20 35 fs 1.0 D 22 fs-fsl Well Mod. rapid- rapid L L s ow. & aeolian 6.1 0.15 85 65 779 Chelsea 0-20 34 fs 1.0 D 20 fs Well Rapid L L s ow. &; aeolian 4.5 0.17 70 55 282 Chute 5-40 10 fs 1.0 D 18 fs Well Rapid L L s ow. 8c aeolian 4.0 0.15 60 45 175 Lamont 3-25 7 fsl 1.5 D 25 fsl Well Mod. rapid- rapid L L Ifs ow. & aeolian 7.7 0.24 105 82 501 Morocco 0-2 14 fs 1.0 D 16 fs SW. poor Rapid L L fs-s ow. 8c aeolian 4.3 0.17 90 72 741 Oakville 0-50 7 fs 1.0 D 27 fs Well Rapid L L fs ow. 8c aeolian 4.3 0.15 65 55 54 Plainfield 0-30 8 s-ls 1.0 D 12 s Well Rapid L L s ow. &; aeolian 3.5 0.17 60 48 184 Roby 0-5 10 fsl 1.5 D 22 fsl SW. poor Mod.-mod. rapid L L Ifs-fsl ow. 8c aeolian 8.0 0.20 105 85 178 Ruark 0-2 18 fsl 1.5 D 19 cl. $cl Poor Mod. slow-mod. L L fsl ow. & aeolian 9.5 0.24 105 82 * See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. 58 Bulletin 778 Table 44. Characteristics and Productivity Indexes of Soil Association 51 — Ritchey-New Glarus-Palsgrove Soils^ Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick' ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index'’ Slope range, % Texture and material No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmC 768 Backbone 2-18 8 Is 1 D 20 si Well Moderate L L thin resi. on iims. 4.0 0.24 80 62 29 Uubuque 3-30 1 1 sil 2 c 16 sicl-sil Well Moderate L L thin resi. on lims. 5.9 0.37 80 62 505 Dunbarton 2-45 7 sil 2 c 1 1 sic) Well Moderate L L thin resi. on lims. 4.1 0.37 70 52 511 Dunbarton, chr. 2-45 8 chr. sil 2 c 1 1 chr. sici Well Moderate L L thin resi. on lims. 3.6 0.37 60 45 731 Nassett 5-20 15 sil 3 c 26 sici Well Moderate M M thin resi. on lims. 8.8 0.32 110 90 928 Nn.< Glarus 1-30 8 sil 2 c 20 sic) Well Mod.-mod. slow M M thick c resi. on lims. 6.5 0.37 90 70 752 Oneco 1-12 7 sil 3 c 34 sicl-cl Well-mod. well Moderate M M thin resi. on lims. 8.3 0.32 105 85 429 Palsgrave 2-30 8 sil 2 c 32 sici Well Moderate M M thin resi. on lims. 8.5 0.32 110 88 3 1 I Ritchey 1-12 7 sil 2 c 10 cl Well Moderate L L limestone 3.3 0.37 75 58 509 Whalan 0-25 9 1 2 D 18 l-cl Well Moderate M M thin resi. on lims. 5.8 0.32 95 75 410 Woodbine 2-25 9 sil 2 c 30 sicl-cl Well Moderate M M thin resi. on lims. 7.9 0.37 105 82 ‘ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Soil Association 52 Alford-Goss-Baxter Soils Soil association 52 occurs in southern Illinois in counties that border the Mississippi and Ohio rivers and in other counties as well. This association occupies about 188,100 acres or 0.5 percent of the state’s land area. These soils formed under deciduous forest on steep and strongly dissected upland areas where Devonian and Mississippian limestone bedrock dominates the land- forms. Outcrops of bedrock are common. The Lower Devonian rocks are predominantly siliceous limestone, dolomite, and chert. The large amount of silica appears to have originated as finely divided quartz silt or to have been a product of intensive weathering. The Missis¬ sippian rocks that influence this soil association are dominated by limestone, which in places contains inter- bedded planes of chert or siltstone. The entire region re¬ ceived a mantle of loess, which varies from very thin on most steep slopes to as much as 20 feet or more on the crests of ridges. The well-drained, moderately permeable Goss soils formed in the clayey residuum from cherty limestone on side slopes. They contain chert fragments throughout and have a clayey subsoil. The well-drained, moderately rapidly permeable Clarksville and Bodine soils formed in residuum weathered from the more siliceous cherty lime¬ stones. They have a high content of chert fragments throughout and contain a moderate amount of clay in the subsoil. The well-drained, moderately permeable Alford soils formed in thick loess on the crests of ridges. Baylis soils formed partly in 20 to 40 inches of loess and partly in thick, cherty residuum weathered from lime¬ stone and occur in narrow areas along the middle or upper parts of slopes. The moderately well drained Bed¬ ford soils have a dense and brittle fragipan horizon. They are silty clay or clay in the lower part of the solum. They are moderately permeable above the fragipan and very slowly permeable in and beneath it. The well-drained, moderately permeable Baxter soils formed in cherty residuum weathered from limestone and have a high clay content in the subsoil. The moderately well drained Muren soils and some¬ what poorly drained Iva soils formed in thick loess on ridgetops or nearly level and gently sloping parts of the landscape. They form a drainage sequence with the well drained .Alford soils. These three soils also occur in thick loess on ridgetops and nearly level areas in associations 33 and 53. The major problems on these soils are low available- water storage capacity (except on the soils that formed in loess), low fertility, and susceptibility to erosion. Their surface layer is low in organic matter. In many areas the variable size and irregular shape of fields on narrow ridgetops often hinders the use of large machinery'. The use of many other areas is limited by the steep sloptes and high content of coarse fragments. Most of these soils respond well to good management. The soils that formed in thick loess are among the most productive upland soils of southern Illinois. The steep Soils of Illinois 59 areas are in forest, as are some of the very narrow ridge- tops. Many of the ridgetops and sloping hillsides have been cleared and are used for hayland, meadow, or crop¬ land. The soils on steep, cherty hillsides are very low in productivity. Various characteristics and the productivity indexes of soils in association 52 are given in Table 45. Soil Association 53 Alford-Wellston Soils Soil association 53 occurs in southern Illinois in several counties along the Mississippi and Ohio rivers. It occupies about 116,400 acres or 0.3 percent of the state’s land area. The .soils in this association formed under deciduous forest on steep and strongly dissected upland areas where the shape of the landscape is determined by the bedrock. The bedrock is predominantly sandstone, with inter- bedded layers of siltstone and shale. Outcrops of bedrock are common, and many hillsides are broken by rock escarpments or strewn with boulders and talus. The region in which these soils occur received a mantle of loess that varies from very thin on steep slopes to as much as 20 feet or more thick on the crests of some ridges. In general, these soils are well drained, although some of the associated soils that formed in loess are moderately well drained or somewhat poorly drained. The well-drained, moderately permeable Alford soils formed in loess. They commonly occur on the upper parts of slopes and on ridgetops. They have silty clay loam subsoil and lack coarse fragments. The well- drained, moderately permeable Wellston soils formed in 20 to 40 inches of loess and residuum weathered from sandstone, siltstone or shale. They are silt loam or silty clay loam in the upper part of the solum and are loamy and contain coarse fragments in the lower part. They are the dominant soil on the slopes in many parts of this soil association. The well-drained Westmorc soils also formed in 20 to 40 inches of loess and loamy residuum, with limestone at depths of more than 48 inches. The well drained Berks, Muskingum, and Neotoma soils are located on the most rugged parts of the topography. They formed in residuum weathered from interbedded silt¬ stone, sandstone, and shale. Berks soils contain more than 35 percent coarse fragments in the subsoil and Muskingum contains between 10 and 30 percent. Neo¬ toma soils contain more than 35 percent coarse fragments in the subsoil and have a more highly developed subsoil than Berks soils. Zanesville soils formed in 24 to 48 inches of loess over residuum weathered from interbedded sandstone, siltstone, and shale. They have a fragipan horizon in the lower part of the subsoil. Idle moderately well drained Muren soils and the somewhat poorly drained Iva soils formed in thick loess and are nearly level or gently sloping. They form a drain¬ age sequence with the well drained .Mford soils, and also occur in associations 33 and 52. The major problems on these soils are low available- water holding capacity in soil layers that contain coarse fragments or fragipan horizons, low fertility, low organic matter in the surface layer, and susceptibility to erosion. The rock escarpments, steep slopes, and rugged topog¬ raphy limit the use of many areas. The irregular size and shape of fields on the narrow ridgetops hinder the use of large machinery on many farms. Table 45. Characteristics and Productivity Indexes of Soil Association 52 — Alford-Goss-Baxter Soils^ Surface soil Subsoil Sub> stratum Available Productivity Slope range, % Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. Texture and material water to 60 inches, in. Erodi- bility factor, K index° No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmt. 308 Alford 1-40 9 sil 2 c 40 sict Well Moderate M M sil loess 12.0 0.37 125 100 599 Baxter 2-30 9 chr. sil 2 c 51 chr. sicl- c Well Moderate L L chr. c resi. on lims. 7.6 0.32 50 40 472 Baylis 8-30 9 sil 2 c 51 sicl-chr. sicl Well Moderate L L chr. c resi. on lims. 8.6 0.37 95 75 598 Bedford 1-7 9 sil 2 c 51 sicl-c Mod. well Slow-v. slow L L sic-c resi. on lims. 8.7 0.43 75 58 471 Bodine 4-60 8 chr. sil 2 c 52 V. chr. sicl-sic Well Mod. rapid L L chr. sic-c resi. on lims. 5.1 0.28 35 30 471 Clarksville 2-60 13 chr. sil 2 c 47 V. chr. sicl-sic Well Mod. rapid L L chr. sic-c resi. on lims. 5.3 0.28 35 30 606 Goss 2-45 19 chr. sil 2 c 41 chr. sic Well Moderate L L chr. sic-c resi. on lims. 7.2 0.24 50 38 454 Iva !-4 13 sil 2 c 36 sicl SW. poor Slow M M sil loess 12.1 0.43 135 108 453 Muren 1-6 1 1 sil 2 c 36 sicl Mod. well Mod. slow M M sil loess 12.1 0.37 130 102 ^ See abbreviations at end of Key to Illinois Soils, page IS. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. 60 Bulletin 778 The steep and rocky parts of this association are pre¬ dominantly wooded. Many other parts, particularly the ridgetops and upper parts of side slopes, are cleared and used for cropland. Corn, soybeans, wheat, milo, and hay are the principal crops. These soils respond well to good management. The Alford, Muren, and Iva soils, which formed in thick loess on ridgetops, are among the most productive soils of southern Illinois. Various character¬ istics and the productivity indexes of the soils in associa¬ tion 53 are given in Table 46. Soil Association 54 Hosmer-Zanesville-Berks Soils Soil association 54 occurs in a number of counties in extreme southern Illinois in the region of the Ozark up¬ lift that extends across the southern part of the state. This association is beyond the limit of continental glacia¬ tion, and its topography is determined by the bedrock. It occupies about 489,800 acres or 1.4 percent of the state’s land area. This association occurs on rough, sloping, and dis¬ sected uplands. The slopes range from nearly level to steep. Outcrops of bedrock, rock escarpments, and talus boulders are common in many places. Many areas of this association are located on the sides of entrenched drain- ageways. Good drainage of the landforms is afforded by the streams and tributaries. The bedrock is primarily interbedded sedimentary rocks of Pennsylvanian or Mis- sissippian age. The strata are broken by a complex of faults and have been tilted by the sinking of the central part of the basin. Hicks Dome, a prominent feature in this association, is probably the result of a deep igneous intrusion. Some cretaceous rocks on the coastal plains and some Pleistocene materials in the form of loess and till are also included in this area. The soils formed under deciduous forest and are light colored. The moderately well drained Hosmer soils are in a drainge sequence with the well drained Wartrace, some¬ what poorly drained Stoy and poorly drained Weir soils. Hosmer and Stoy soils, which are among the major soils of this association, occur in areas that have about 7 to 12 feet of loess over residuum weathered from interbedded sandstone, siltstone, or shale. This drainage sequence also occurs in association 35, which is underlain by till rather than bedrock. Zanesville, Wellston, and Westmore soils occur in the more sloping areas where the loess is thinner. These soils formed in both loess and the underlying residuum weathered from stratified sandstone, siltstone, and shale. Zanesville and Lax soils contain a dense, brittle fragipan horizon in the lower part of the subsoil that restricts root growth and water movement. Hosmer and Stoy soils also have a restrictive horizon. The well-drained Berks, Musk¬ ingum, and Neotoma soils occur on the most rugged parts of the topography. They formed in residuum weathered from interbedded siltstone, sandstone, and shale. Both Berks and Neotoma soils contain more than 35 percent coarse fragments in the subsoil, but Neotoma .soils have a more highly developed subsoil than Berks soils. Muskingum soils contain between 10 and 30 per¬ cent coarse fragments in the subsoil. The well drained Beasley soils formed in calcareous shale or limestone and have clayey subsoil. The moderately well drained Lax soils and the well drained Brandon and Saffell soils formed in the gravelly coastal plains sediments. Brandon and Lax soils contain a component of loess or silty mate¬ rial in the upper part. The major problems on these soils are susceptibility to erosion, low organic matter in the surface layer, low fertility, and low available-water holding capacity in soil layers that contain coarse fragments or fragipan horizons. Rock escarpments, steep slopes, and rugged topography limit the use of many areas. The fields of irregular size and shape on the more narrow ridgetops are often difficult to farm with large farm machinery. Most of the sides of the incised drainageways and the steep and rocky parts of this association are wooded. Many other parts are cleared and used for cropland, including ridge crests, upper parts of side slopes and some sloping benched areas between escarpments. Corn, soybeans, wheat, milo, and hay are the principal crops; some areas are used for pasture. These soils respond well to good management. Various characteristics and the productivity indexes of the soils in association 54 are given in Table 47. Soil Association 55 Grantsburg-Zanesville-Wellston Soils Soil association 55 occurs in relatively small areas in several counties of extreme southern and southeastern Illinois. The topography of these areas is determined by bedrock, and glaciation has had little or no effect on them. They occur on high domes of bedrock, and are dissected by the major drainage network. Association 55 occupies about 388,000 acres or 1.1 percent of the state’s land area. This association is located on dissected and sloping uplands, and most of it is covered with a mantle of loess ranging from very thin to as much as 7 feet thick. The loess is thickest on the crests of the ridges and thin¬ ner on the secondary point ridges and sides of the hills. The underlying bedrock is primarily interbedded sedi¬ mentary rocks. Rock outcrops or rock escarpments occur in many places. The areas are afforded good drainage by the sloping topography and the network of streams and tributaries. Slopes range from nearly level to steep. The Soils of Illinois 61 Table 46. Characteristics and Productivity Indexes of Soil Association 53 — Alford-Wellston Soils' Surface soil Subsoil Sub- Available Productivity Avg. Avg. OM Avg. stratum Erodi- water to index'’ Slope Supply of Texture thick- in thick- 60 bility High Avg. No. and name range, ness, plow layer, Lime ness. Natural and inches, factor. of soil series % in. Texture % group in. Texture drainage Permeability P K material in. K mgmt. mgmi. 308 Alford 1-40 9 sil 2 C 40 sicl-sil Well Moderate M M sil loess 12.0 0.37 125 100 3-45 10 1 2 D 16 sh 1-1 Well Mod.-mod. rapid L L sh-l resi. on ss, sis, sh 4.9 0.24 35 30 454 Iva 1-4 13 sil 2 C 36 sicl SW. poor Slow M M sil loess 12.1 0.43 135 108 453 Muren 1-6 1 1 sil 2 C 36 sicl Mod. well Mod. slow M M sil loess 12.1 0.37 130 102 425 Muskingum 5-70 1 1 stony sil 2 D 21 sil, ch sil Well Moderate L L ch sil-1 5.9 0.28 35 30 resi. on ss. sis. sh 6-35 9 stony sil 2 D 31 ch sil Well Mod. rapid L L fl 1 resi. on 7.0 0.20 35 30 977 J sis. ss 339 Wellston 0-35 7 sil 2 c 29 sicl-sil, Well Moderate L L ch 1 resi. 8.2 0.37 70 50 ch 1 on sis, ss, sh 940 Westmore 2-50 6 sil 2 c 54 slc!< Well Mod.-slow L L c resi. on ss, sis, sh, lims. 9.2 0.37 90 72 340 Zanesville 0-20 7 sll 2 c 32 sicl, sil, 1 Well-mod. Mod.-slow L L scl resi. on 8.7 0.37 85 65 well ss. sis, sh ‘ See abbreviations at end of Key to Illinoia Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Sail Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Table 47. Characteristics and Productivity Indexes of Soil Association 54 — Hosmer-Zanesville-Berks Soils^ Surface soil Subsoil Sub¬ stratum Available Productivity Avg. Avg. OM Avg. Erodi- water to index'’ Slope Texture thick- in thick- 60 bility Supply of High Avg. No. and name range, ness, plow layer. Lime ness. Natural and inches. factor. of soil series % in. Texture % group in. Texture drainage Permeability P K material in. K mgmt. mgmt. 691 Beasley 2-20 7 sil 2.0 C 22 sic, c Well Mod. slow L L c, sic resi. 8.8 0.43 60 45 on calc, sis, sh. 955) lims. 986/^'’'^ 3-45 10 1 2.0 D 16 sh 1-1 Well Mod.-mod. rapid L L sh 1 resi. on ss, sis. sh 4.9 0.24 35 30 956 Brandon 2-30 9 sil 2.0 C 21 sil, sicl Well Mod.-mod. L L gl si on 8.5 0.37 85 68 rapid coastal plains gl mat. ^14 Hosmer 1-25 12 sil 1.5 C 40 sicl-sil Mod. well Mod.-slow L M sil loess n.i 0.43 115 88 628 Lax 2-12 7 sil 2.0 C 53 sicl-gl cl Mod. well Mod.-slow L L gl cl on coastal 8.3 0.43 80 65 plains gl mat. 425 Muskingum 5-70 11 stony sil 2.0 D 21 sil, ch sil Well Moderate L L ch sil-1 5.9 0.28 35 30 resi. on ss, 9761 sis. sh 977/Neotoma 6-35 9 stony sil 2.0 D 31 ch sil Well Mod. rapid L L fl ! resi. 7.0 0.20 35 30 on sis, ss 956 Saffell 1-30 8 gl sil 2.0 D 42 gl scl Well Moderate L L gl si on coastal 5.6 0.28 60 48 plains gl mat. 164 Stoy 0-10 13 sil 2.0 C 35 sicl SW. poor Slow L M sil loess 10.9 0.43 115 90 215 Wartrace 1-30 10 sil 2.0 C 30 sicl Well Mod.-mod. M M sil loess 10.9 0.37 120 92 slow on lims. 165 Weir 0-3 16 sil 2.0 C 30 sicl Poor V. slow-slow L L sil loess 11.0 0.43 110 85 339 Wellston 0-35 7 sil 2.0 C 29 sicl, sil, Well Moderate L L ch 1 resi. 8.2 0.37 70 50 ch 1 on sis, ss, sh 940 Westmore 2-50 6 sil 2.0 C 54 sicl< Well Mod.-slow L L c resi. on 9.2 0.37 90 72 ss. sis. sh, lims. 340 Zanesville 2-20 7 sil 2.0 C 32 sicl, sil Well-mod. Mod.-slow L L s cl resi. 8.7 0.37 85 65 well on ss, sis, sh ‘ See abbreviations at end of Key to Illinois Soils, page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. 62 Bulletin 778 soils formed under deciduous forest and are light colored. The moderately well drained Grantsburg soils and the somewhat poorly drained Robbs soils form a drainage sequence. The Grantsburg soils, which are among the major soils in this association, formed in loess and con¬ tain root-restricting fragipan horizons in the lower part of the subsoil. They generally occur on the crests of the ridges. The well-drained and moderately well drained Zanesville soils and the well-drained Wellston soils are located on the lower secondary ridges and on the side slopes where the loess is thinner. They formed in both the loess and the underlying residuum weathered from strat¬ ified sandstone, siltstone, and shale. The Zanesville soils also contain a fragipan horizon. The well drained Berks, Muskingum, and Neotoma soils occur on the more rugged parts of the topography, commonly on the lower parts of the slopes. They formed in residuum weathered from interbedded siltstone, sandstone, and shale. Berks and Neotoma soils both contain more than 35 percent coarse fragments in the subsoil, but Neotoma soils have a more highly developed subsoil than Berks. Muskingum soils formed in materials similar to those of Berks and Neotoma, but contain between 10 and 20 percent coarse fragments in the soil. The well-drained Beasley soils formed in calcareous shale or limestone and have clayey subsoils. The major problems on these soils are susceptibility to erosion, low organic matter in the surface layer, low fertility, and low available-water holding capacity in soil layers that contain coarse fragments or fragipan horizons. The steep slopes, rock outcrops, and rock escarpments limit the use of many areas. Irregularly sized and shaped fields on narrow ridgetops hinder use of large farm machinery in much of this association. Many of the steep and rocky areas are in woodland. Many of the nearly level to moderately steep areas have been cleared and used for cropland. The principal crops are corn, milo, wheat, and hay, although some areas are used for pasture. These soils respond well to good man¬ agement. Some areas are idle and host a succession of plants as the areas revert to woodland. Various char¬ acteristics and the productivity indexes of soils in associa¬ tion 55 are given in Table 48. Soil Association 56 Derinda-Schapville-Eleroy Soils Soil association 56 occurs in several counties in north central and northwestern Illinois. It occupies about 89,100 acres or 0.3 percent of the state’s land area. The soils in this association occur on nearly level to very steep uplands, many on the steep side slopes of ravines or other drainageways. They formed in thin to moderately thick loess or medium-textured drift on either shale or sandstone, with interbedded limestone in a few areas. Some of these soils formed under grass and are dark colored, others under forest and are light-colored. The soils range from very poorly drained to well drained. The well-drained and moderately well drained Derinda and Schapville soils formed in about 15 to 30 inches of loess and in the underlying clayey residuum weathered from calcareous shale. They have silty clay loam texture Table 48. Characteristics and Productivity Indexes of Soil Association 55 — Grantsburg-Zanesville-Wellston Soils' Surface soil Subsoil Sub- Available water to 60 inches, in. Avg. thick¬ ness, in. Avg. OM Avg. thick¬ ness, in. stratum Erodi- bility factor, K index^ Slope range, % SuddIv of Texture and material No. and name of soil series Texture plow layer, % Lime group Texture Natural drainage Permeability P K High mgmt. Avg. mgmt. 691 Beasley Q55 *1 2-20 7 sil 2.0 c 22 sic, c Well Mod. slow L L c, sic resi. on calc, sis, sh, lims. 8.8 0.43 60 45 986 J ^ Berks 3-45 10 1 2.0 D 16 sh 1-1 Well Mod.-mod. rapid L L sh 1 resi. on ss, sis, sh 4.9 0.24 35 30 301 Grantsburg 2-15 7 $11 1.5 C 45 sil-sici Mod. well Mod.-v. slow L L sil loess on ss. sis, sh 9.4 0.43 105 80 425 } 9761 wluskingum 1 5-70 1 1 stony sil 2.0 D 21 sil, ch-sil Well Moderate L L ch sil-l resi. on ss, sis. sh 5.9 0.28 35 30 977 J r Neotoma 6-35 9 stony sil 2.0 D 31 ch sil Well Mod. rapid L L fl 1 resi. on sis, ss 7.0 0.20 35 30 335 Robbs 0-3 13 sil 2.0 C 36 sicl-sil SW. poor Slow-v. slow L L sil loess on ss, sis, sh 9.9 0.43 105 80 339 Wellston 0-35 7 sil 2.0 C 29 sicl, sil ch 1 Well Moderate L L ch 1 resi. on sis, ss, sh 8.2 0.37 70 50 340 Zanesville 2-20 7 sil 2.0 C 32 sicl, sil Well-mod. well Moderate-slow L L scl resi. on ss, sis, sh 8.7 0.37 85 65 * See abbreviations at end of Key to Illinoia SoiU, page 13. ** The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Soils of Illinois 63 in the upper part of the subsoil and silty clay or clay in the lower part. The light-colored Derinda soils formed under forest and the dark-colored Schapville under prairie grass. The somewhat poorly drained Shullsburg and the poorly drained Calamine soils form a drainage sequence with Schapville soils and developed in similar materials. The well-drained and moderately well drained Keltner, Massbach, and Eleroy soils formed in about 30 to 50 inches of loess and in residuum weathered from shale. They are clayey in the lower part of the subsoil. The light-colored Eleroy soils formed under forest, the dark-colored Keltner soils under prairie grass, and the moderately dark Massbach soils under both forest and prairie grass in transition zones. The somewhat poorly drained, moderately dark Ridott soils form a drainage sequence with Massbach soils and developed in similar materials. The somewhat poorly drained Loran and poorly drained Calamine soils form a drainage sequence with Keltner soils. The moderately well drained Gosport soils formed in residuum weathered from acid shale and contain little or no loess on the surface. They have a high content of clay in the subsoil, but the development of their subsoil is not strongly expressed. They occur mostly on the lower part of slopes along incised drainageways. The well- drained and moderately well drained, light-colored Mar¬ seilles series formed under forest in about 15 to 30 inches of loess and in the underlying residuum weathered from acid shale, and contain more clay in the lower part of the subsoil than in the upper part. These soils were mapped in LaSalle County. somewhat poorly drained variant, Marseilles gray subsoil, was also mapped in similar materials. The well-drained and moderately well drained High Gap soils and the somewhat poorly drained Shadeland soils formed in thin (less than 10 inches) loess, glacial drift, and residuum weathered from acid, strati¬ fied sandstone, siltstone, and shale. They formed under forest and are light colored. They are mapped in Rock Island and Grundy counties. The well- or excessively drained Boone and Eleva soils formed in residuum weathered from sandstone. They occur in Ogle County. The sandy Boone soils are also located in LaSalle County. The light-colored, well-drained Gale soils formed in 18 to 36 inches of loess and in residuum weathered from acid sandstone under forest. They are located in Carroll and LaSalle counties. The dark-colored, well-drained Hesch soils formed in loamy residuum weathered from acid sandstone under grass. They are located in LaSalle County. Two variants of the Hesch soils are also recog¬ nized; one is thin to sandstone bedrock and the other poorly drained. The major problems on these soils are steep slopes, generally shallow depths to bedrock, low available-water holding capacity, and low fertility. The high clay content of the soils formed in residuum weathered from shale, and the generally low clay content of the soils formed in residuum weathered from sandstone contribute to the lower available-water holding capacity and low fertility of these soils. Steep areas along ravines are very suscepti¬ ble to erosion. These soils are predominantly in pasture or woodland or are idle. Although some areas are in cropland, most are too steep for that use. These soils are not highly productive but respond favorably to good management practices, especially the ones that have thicker loess covers. Various characteristics and the productivity indexes of the soils in association 56 are given in Table 49. Soil Association 57 Haymond-Petrolia-Karnak Soils Soil association 57 occurs in large and small flood- plains in the southern half of Illinois, and in the western and northwestern parts of the state in floodplains drain¬ ing areas of light-colored soils. This association occupies about 1,738,700 acres or 4.9 percent of the state’s land area. These soils formed in stratified clayey to sandy allu¬ vium under deciduous forests. They are all low to medium in organic matter content, and all have light- colored surfaces. Most are nearly level but some are gently sloping. Haymond soils are well drained and form a drainage sequence with the somewhat poorly drained Wakeland soils and the poorly drained Birds soils. All of these soils formed in silty soil materials. Haymond and Wakeland soils are moderately permeable and Birds soils moder¬ ately slowly permeable. Haymond soils usually occur on natural levees and higher in the floodplain than Wake¬ land soils. Birds soils are located in the lower parts of the floodplain. The well and moderately well drained Sharon soils form a drainage sequence with the somewhat poorly drained Belknap soils and the poorly drained Bonnie soils. This sequence is similar, except for being more acid, to the Haymond, Wakeland, and Birds sequence. All of these soils formed in silty alluvium. The moderately permeable Sharon soils occur on nearly level and gently sloping natural levees and higher parts of the floodplain. Belknap soils are located on nearly level and gently slop¬ ing parts of the floodplain and are moderately to moder¬ ately slowly permeable. Bonnie soils occur on nearly level or depressional parts of the floodplain; they are moder¬ ately slowly permeable. Arenzville soils, which are well and moderately w'ell drained, form a drainage sequence with the somewhat poorly drained Orion soils. These soils 64 Bulletin 778 Table 49. Characteristics and Productivity Indexes of Soil Association 56 — Derinda-Schapville-Eleroy Soils' Surface soil Subsoil Sub- Avg. Avg. OM Avg. water to 60 inches, in. Erodi- bility factor, K index^ Texture and material No. and name of soil series Slope range, % thick* ness, in. in plow layer. Texture % Lime group thick* ness, in. Texture Natural drainage Permeability Supply of P K High mgmt. Avg. mgmt. 397 Boone 2-40 3 Ifs 1.5 D 4 fs Well Rapid L L san. resi. on ss 4.4 0.15 50 42 746 Calamine 0-12 20 sil 4.0 B 20 sicl-sic Poor Slow-v. slow L L sic-c resi. on calc, sh 9.4 0.28 115 88 417 Dennda 4-12 7 sil 2.0 c 18 sicl-sic Mod. well- well Slow-v. slow L L sic-c resi. on calc, sh 5.5 0.43 80 62 647 Eleroy 2-30 12 sil 2.0 c 29 sicl'sic Mod. well- well Mod.-slow L L sic-c resi. on calc, sh 8.7 0.37 105 80 761 Eleva 2-35 5 sl 1.5 D 25 si Well Mod.-mod. rapid L L fs-sl on ss 6.8 0.24 65 50 413 Gale 2-60 8 sil 2.0 c 21 sil-sicl Well Mod.-mod. rapid L L 1-sl on ss 8.5 0.37 85 68 551 Gosport 5-45 7 sil 2.0 c 20 sic-c Mod. well Very slow L L c resi. on 6.9 0.43 60 45 390 Hesch 2-45 12 fsl 3.0 c 20 sl-l Well Mod.-mod. rapid L L san. resi. on ss 6.4 0.20 100 78 389 Hesch, thin to ss 0-5 5 Is 3.0 c 2 Is Well Rapid L L sandstone 2.0 0.20 50 40 537 Hesch, gray subs 0-5 13 fsl 4.0 c 24 sl-l Poor Mod. or mod. rapid L L San. resi. on ss 7.1 0.20 115 95 556 High Gap 1-12 7 1 2.0 c 27 cl-scl Well-mod. well Moderate L L sl resi. on ss. sh, sis 7.2 0.37 100 78 546 Keltner 2-15 13 sil 3.5 B 28 sicl'sic Mod. well- well Mod.-slow L L sic-c resi. on calc, sh 8.8 0.32 110 88 572 Loran 1-10 13 sil 4.0 B 32 sicl-sic SW. poor Mod. slow L L sic-c resi. on calc, sh 9.5 0.28 120 95 549 Marseilles 1-15 11 sil 2.0 c 28 sicl-sic Mod. well- well Mod.-slow L L cl resi. on sh 10.5 0.37 105 82 393 Marseilles, gray subs. 0-4 10 sil 2.0 c 33 sic SW. poor Mod. slow L L cl resi. on sh 9.6 0.37 85 68 753 Massbach 1-15 11 sil 3.0 c 35 sicl-sic Well-mod. well Mod.-slow L L sic-c resi. on calc, sh 9.5 0.32 105 82 743 Ridott 1-10 11 sil 3.0 c 33 sicl-sic SW. poor Mod.-v. slow L L sic-c resi. on calc, sh 8.9 0.32 110 90 418 Sckapville 2-20 12 sil 3.5 B 15 sicl-sic Mod. well- well Mod. V. slow L L sic-c resi. on calc, sh 6.3 0.32 90 72 555 Shadeland 0-6 10 1 2.0 c 23 sicl-cl SW. poor Mod. slow L L sl resi. on ss, sh, sis 8.5 0.37 105 82 745 Shullsburg 1-25 17 sil 3.0 B 20 sicl-sic SW. poor Mod.-v. slow L L sic-c resi. on calc, sh 8.0 0.32 115 90 * See abbreviations at end of Key to Illinoii Soil*, page 13. „ l i j ■ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion condiuons can be obuined from Extension circular 1156, Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. are light colored and silty in the upper part and dark colored and silty or moderately fine-textured in the lower part. Arenzville and Orion soils are moderately perme¬ able and nearly level, although Arenzville soils commonly occur in higher parts of the floodplain. The well-drained Genesee soils form a drainage se¬ quence with the somewhat poorly drained Shoals soils. These soils formed in silty and loamy alluvium that is calcareous in the lower part. They are moderately per¬ meable and nearly level. The well and moderately well drained Juneau soils form a drainage sequence with the poorly drained Washtenaw soils. These soils formed in silty or loamy alluvium and underlying glacial drift. Juneau soils are located on nearly level and gently slop¬ ing parts of the landscape. They are moderately perme¬ able. Wastenaw soils occur on nearly level parts of the landscape and are moderately slowly or slowly permeable. Banlic soils are somewhat poorly drained and formed in silty alluvium. They are located on nearly level parts of the floodplain, are slowly {jermeable, and have dense layers in the lower part. Bungay soils are poorly drained and slowly permeable. Burnside soils are well and moder¬ ately well drained, formed in silty alluvium in the upper part and flaggy loam in the lower part, and are moder¬ ately permeable. They occur on nearly level and gently sloping parts of the floodplain. The poorly drained Cape soils formed in moderately fine-textured alluvium over clayey alluvium. They are slowly or very slowly perme¬ able and are located on nearly level parts of the flood- plain. Dorchester soils are well and moderately well drained. They formed in light or moderately dark, calcareous, silty alluvium. These soils have moderate permeability. They are on nearly level parts of the floodplain. Dor¬ chester soils, cobbly subsoil variant, are well drained. They formed in calcareous silty alluvium in the upper part and cobbly loam in the lower part. These soils are located on nearly level parts of the floodplain and are moderately permeable. Dupo soils are somewhat poorly drained. They formed in silty alluvium over clayey Figure 2. Parent Material Soil Regions of Illinois +1 s ° — o 5 2 i oorly drained, formed in very clayey alluvium and are very slowly permeable. These soils are located on nearly level or depressional parts of the flood- plain. The well and moderately well drained Jules soils formed in calcareous silty alluvium, are moderately permeable, and occur on nearly level parts of the flood- plain. Poorly drained Karnak soils formed in acid, clayey alluvium. They are often located in sloughs and swales and are slowly to very slowly jjermeable. The poorly drained Petrolia soils formed in moderately fine-textured, slightly acid alluvium. They are moderately slowly per¬ meable and occur on nearly level parts of the floodplain. Piopolis soils are poor and very poorly drained. They formed in moderately fine-textured, strongly acid allu¬ vium, are slowly permeable, and occur on nearly level parts of the floodplain. The excessively drained Sarpy soils formed in calcareous sandy alluvium, are rapidly or very rapidly permeable, and occur on gently sloping or sloping parts of the floodplain. Stonelick soils are well drained and formed in calcareous sandy and silty allu¬ vium. They are moderately rapidly permeable and occur on nearly level parts of the floodplain. The very poorly drained Wallkill soils formed in silty or sandy alluvium over organic soil materials. They are moderately or rapidly permeable and are located on nearly level or de¬ pressional parts of the floodplain. The major problems on these soils are flooding, wet¬ ness, and low organic matter content in the surface soil. Other problems on some of these soils are clayey surface textures and slow or very slow permeability. Most areas of these soils are cultivated, except where the floodplains are narrow or where they are cut up by streams or flood frequently. Some areas are protected from flooding by levees. The principal crops are corn and soybeans; some small grains are grown in areas that are protected from flooding. These soils respond well to good management. The wet soils can be drained by tile or surface ditches. However, in the fine-textured soils, such as Karnak and Jacob, tile do not function adequately. Various characteristics and the productivity indexes of the soils in association 57 are given in Table 50, page 66. DEVELOPMENT OF ILLINOIS SOILS The development of Illinois soils has been determined primarily by soil parent materials, climate, vegetation, relief and natural drainage, and time. Some of the above factors may have been altered by artificial drainage, clearing, irrigation, cultivation, and fertilization, but these practices (with the exception of excavating and land filling) have not greatly influenced soil development in Illinois. The most important kind of excavating and land fill¬ ing or soil disturbance currently taking place in the state is surface mining for coal. Soils and geological materials (overburden above coal veins) are first removed and then replaced after the coal layers have been hauled away to a coal processing center. The surface mining industry is under strict regulations to leave mined and reclaimed areas with high potential for producing crops commonly grown in that area. Because surface mining and reclamation disturb or mix the soil thoroughly, they initiate what is essentially a new cycle of soil formation. By 1982 about 220,000 acres had been surface-mined in Illinois. Most of this acreage is in the southern, south¬ western, and western parts of the state. Partly because several thousand acres are surface-mined in Illinois each year, these areas of disturbed soils are not show'n on the General Soil Map of Illinois. Information on surface mining in Illinois is available from the Illinois State De¬ partment of Mines and Minerals in Springfield, Illinois. Illinois is located in the central or midwestern part of the United States between 87.5 and 91.5 degrees west longitude and 37 and 42.5 degrees north latitude. The state is in the south central part of the north central states, and is nearly 400 miles in length from north to south and about 200 miles at its maximum width from west to east. Illinois has a lower mean elevation than the surrounding states of Indiana, Wisconsin, Iowa, ^Missouri, and Kentucky. Its elevation ranges from 268 feet at the southern tip to 1,241 feet above sea level at Charles Mound in Jo Daviess County in the northwestern part of the state. Mean elevation is about 600 feet above sea level. The relatively low elevation of Illinois and its location near the confluence of the major drainage lines in the Midwest probably influenced the direction and extent of the various ice sheets that moved down from the north during glacial times and greatly influenced the develop¬ ment of present-day soils. The Mississippi River is on the west side of the state, the Ohio River on the south, the Wabash River on the southeast, and Lake Michigan on the northeast. The Illinois River and its tributaries drain much of the central part of the state. 4 hese rivers were important in the distribution of the loess and outwash soil parent materials in the state. Lake Michigan, in part gouged by glacial action, was the path of one of the major ice lobe invasions during glacial times. Generally favorable soil parent materials and a lack of extreme weathering and soil development since glacial 66 Bulletin 778 times have given Illinois productive soils. Good soils, a favorable climate for crop production, a high percent¬ age of nearly level to gently sloping land, and favorable markets have all contributed to Illinois’s high ranking as an agricultural state. Soil Parent Materials The parent materials of mineral soils are formed by the disintegration and decomposition of rock. These ma¬ terials may be moved from place to place by water, wind, or glaciers, and may have been sorted or mixed to vary¬ ing degrees. Organic soils (peats and mucks) are formed from the remains of plants. Fifteen different areas of soil parent materials (desig¬ nated by Roman numerals) are shown on the Illinois map in Figure 2. The sixteenth area, organic materials (peats and mucks) is not indicated because of its small extent. Figure 2 shows soil parent material regions in Table 50. Characteristics and Productivity Indexes of Soil Association 57 — Haymond-Petrolia-Karnak Soils' Surface soil Subsoil Sub- Available Productivity Avg. Avg. OM Avg. stratum Erodi- water to index^ Slope Supply of Texture thick- in thick- 60 bility High Avg. No. and name range, ness, plow layer, Lime ness, Natural and inches. factor, of soil series % in. Texture % group in. Texture drainage Permeability P K material in. K mgmt. mgmt. 78 Arenzville 0-3 10 sil 2.0 C 30 sil Mod. well- well Moderate M M sil-sicl alluvium 11.5 0.37 135 no 787 Banlic 0-2 7 sil 2.0 C 18 sil SW. poor Slow L L sil alluvium 9.6 0.43 115 88 382 Belknap 0-5 13 sil 2.0 C 27 sil SW. poor Mod. slow-mod. L L sil alluvium 12.6 0.37 120 95 334 Birds 0-2 8 sil 2.0 C 32 sil Poor Mod. slow L M sil alluvium 12.8 0.43 125 100 108 Bonnie 0-2 8 sit 2.0 C 17 sil Poor Slow-mod. L L sil alluvium 12.0 0.43 no 85 444 Bungay 0-2 10 sicl-sic 2.0 B 40 sic Poor Slow L M sic-sicl alluvium 9.0 0.32 105 82 427 Burnside 0-4 8 sil 1.5 c 40 sil-fl. 1 Well-mod. well Moderate L L ss. br. 7.4 0.37 105 80 422 Cape 0-2 10 sicl 2.0 B 32 sic Poor Slow-v. slow L M sic-sicl alluvium 8.4 0.32 105 82 239 Dorchester 0-3 8 sil 2.5 c 32 sil Well-mod. well Moderate M M sil alluvium 12.6 0.37 130 105 578 Dorchester, cobbly 0-3 8 sil 2.5 c 16 sil Well Moderate M M cobbly 1 8.6 0.37 120 95 180 Dupo 0-2 7 sil 1.5 c 25 sil SW. poor Mod. slow-slow L M sic. alluvium 10.5 0.37 130 108 475 Elsah 0-5 10 sil 1.5 c 22 ch. sil Well Mod.-mod. rapid L L V. ch. 1 alluvium 6.9 0.37 115 90 431 Genesee 0-2 8 sil 2.0 c 24 sil-1 Well Moderate L L sl-sil alluvium 10.8 0.37 135 108 331 Haymond 0-5 10 sil 2.0 c 34 sil Mod. well- well Moderate L M sil-1 alluvium 12.8 0.37 140 112 85 Jacob 0-1 6 c 2.0 B 28 c-sic Poor-v. poor V. slow L L c-sic alluvium 6.6 0.28 70 52 28 Jules 0-2 7 sil 1.5 c 14 sil Well-mod. well Moderate L M sil alluvium 12.1 0.37 125 98 782 Juneau 0-6 6 sil 1.5 c 32 sil Well-mod. well Moderate L M sil-sic) wash 11.3 0.37 130 105 426 Karnak 0-1 6 sic 2.5 B 40 sic Poor Slow-v. slow L M sic< alluvium 7.2 0.32 100 78 415 Orion 0-2 6 sil 2.0 c 16 sil SW. poor Moderate M M sil-sici alluvium 10.6 0.37 130 105 288 Petroha 0-2 8 sicl 2.5 B 30 sicl Poor Mod. slow L M sil-sicI alluvium 11.0 0.32 130 102 420 Piopolis 0-2 7 sicl 2.0 B 31 sicl Poor Slow L M sil-sicI alluvium 11.0 0.43 115 90 92 Sarpy 1-12 8 fs 1.0 D 12 fs Well V. rapid-rapid L L Ifs alluvium 5.4 0.15 75 60 72 Sharon 0-5 10 sil 1.5 c 25 sil Mod. well- well Moderate L M sil-sl alluvium 12.3 0.37 125 98 424 Shoals 0-2 9 sil 2.0 c 19 sil SW. poor Mod.-mod. rapid L L sil-sl alluvium 10.5 0.37 140 118 665 Stonelick 0-2 12 fsl 1.5 D 16 si Well Mod. rapid L L si alluvium 6.2 0.24 90 75 333 Wakeland 0-4 8 sil 2.0 c 23 sil SW. poor Moderate L M sil alluvium 12,4 0.37 135 108 292 Wallkill 0-2 8 sil 3.0 c 20 sil Poor Mod.-rapid L M Muck & p>eat 14.4 0.32 125 100 296 Washtenaw 0-2 10 sil 2.0 c 14 sil-cl Poor Mod. slow-slow L M sil-l wash 12.3 0.37 130 105 ^ See abbreviations at end of Key to lllinoU SoiU» page 13. ^ The productivity indexes listed here apply to uneroded soil on a 0 to 2 percent slope. Guidelines for adjusting productivity indexes to reflect other slope and erosion conditions can be obtained from Extension circular 1156» Soil Productivity in Illinois, or from county Extension and Soil Conservation Service district offices. Soils of Illinois 67 Illinois, and is not a soil map. For general soils informa¬ tion, use the CJeneral Soil Map at the back of this pub¬ lication. Some of the areas in Figure 2 are distinguished from one another by variations in the thickness of loess or other geological materials or combinations of mate¬ rials. In addition, the various soil parent materials are grouped by color. For example, the first five parent material regions, which have .soils formed primarily from loess, are indicated in blue. The definitions of these areas or soil parent material regions are given in the legend in Figure 2 and in the Key to Illinois Soils. The main types of parent materials of Illinois soils arc loess, outwash, till, and alluvium. Other .soil parent materials, such as bedrock weathered in place and plant remains, arc present but arc not extensive in Illinois. Loess is the principal parent material in soil regions I through V, and is the most extensive in Illinois. Soils developed primarily from loess occupy about 63 percent of the state’s land area, predominating in the western, central, and southern parts. Loess is a silty wind deposit. During glacial times, the melting of the glaciers pro¬ duced tremendous floods of meltwater that were chan¬ neled down the major river valleys — the Mississippi, Illinois, Wabash, and Ohio. During the periods of low melting, when the flood- waters receded, the wind picked up dust from the dry valley floors and deposited it as loess on the uplands. The loess is the thickest east of the valleys because of prevail¬ ing westerly winds. It is thicker near the valley source areas and gradually becomes thinner with increasing dis¬ tance from the source. In uniform loess deposits, the less weathered, less developed, and more fertile soils are generally formed in the thicker loess near the source. More highly weathered, more acid, and less fertile soils are formed in the thinner loess that is farther from the source. There are at least three main loess blankets in Illinois. The total thickness of the three loess sheets is shown in Figure 3. The Loveland, which is the oldest of the three, is present in some areas of the unglaciated part of the state. Since it is covered by the later loess sheets, how¬ ever, it is of little importance as a soil parent material. The second or middle loess sheet, the Roxana, is present in significant amounts near the upper and lower Missis¬ sippi River valley, the lower Illinois River valley, and the lower Wabash and Ohio River valleys. The Roxana is not of great importance as a soil parent material because it is covered by the Peorian loess. In many areas, how¬ ever, it adds to the total thickness of loess, and has had some influence on the soils that have developed in thin ovenying Peorian loess. The Peorian loess, which was deposited during the Wisconsinan glacial period, when most of northeastern Illinois was last glaciated, is the main parent material of the loess soils in the state. I’he Peorian loess is a good soil parent material. When deposited, it was calcareous and well supplied with plant nutrients (except nitrogen). It was a friable, medium- textured silt loam with a high available-water holding capacity. In some areas of soil associations in which the soils developed primarily from loess, the loess has been worn away by erosion, particularly on steep slopes. In the.se areas, the soils fonned from glacial till, thin loess on glacial till, or from bedrock or bedrock residuum. In some places, bedrock outcrops on very steep slopes. Many of the state’s other soil associations, in which the soils developed primarily from glacial drift or outwash, have thin loess covers that have influenced at least the upper part of the profile of many soils outside the predomi¬ nately loess areas in Illinois. Soil parent material V, moderately thick to thin loess or silty material on me¬ dium-textured Wisconsinan outwash, could be grouped with soils formed from outwash materials; however, to emphasize the silty nature of region V soils, these soils were grouped with loess soils. Outwash materials are important in soil regions IX, X, XI, XII, and part of region V, which occupy about 8 percent of the state’s land area. These materials are most extensive in northern Illinois but also occur along the Mississippi, Illinois, Wabash, and Ohio River valleys as stream terraces (Figure 2). The parent materials in these valleys and outwash areas that had an important in¬ fluence on pre.sent-day soils were deposited by Wiscon¬ sinan glacial meltwaters. These materials vary in texture from gravel to clay. The coarse, gravelly materials were deposited near the glacier front or in the upper reaches of the river valleys. Sand was usually carried somewhat farther than gravel, depending upon the velocity of the running water. Gravelly outwash (area X) and very sandy outwash (area XII) are indicated in red in Figure 2. The finer materials, such as silt and clay, were deposited in quiet water. These silty and loamy outwash areas (IX and XI) are indicated in orange. In bodies of quiet water such as glacial lakes, the sediments are high in clay and silt and are known as lacustrine or lake-bed sediments. Soil region IX is composed mainly of soils formed in lacustrine sediments. In many places the outwash is stratified; that is, it consists of layers of various textured material. The medium-textured outwash is the most desirable outwash parent material. Soils developed from medium-textured outwash compare favorably in crop production with the better loess and till soils. Glacial till is an important soil parent material in northeastern Illinois. Soils developed primarily from till make up soils regions VI, VII, and VIII. They occupy about 12 percent of the state’s land area, and are indi¬ cated in green in Figure 2. In northeastern Illinois, the glacial tills are of Wisconsinan age. Older till of Illinoian 68 Bulletin 778 Figure 3. Approximate loess depths (feet) on uneroded topog¬ raphy in Illinois. age, in which a few soils have formed on the steeper slopes, are present throughout much of the rest of Illi¬ nois. In western Illinois, soils that formed from Kansan till, which is older than the Illinoian, are found on some steep slopes, especially in western and southern Adams County and in northwestern Pike County. The Wiscon- sinan tills in northeastern Illinois are extremely variable in texture, ranging from loamy gravel to clay and includ¬ ing sandy loam, loam and silt loam, silty clay loam, and silty clay. In general, till contains more sand than loess, and commonly includes pebbles and various sizes of boulders. Most of the Wisconsinan tills in Illinois were deposited by a glacial lobe that was channeled south¬ ward through Lake Michigan. The Lake Michigan ice lobe crossed mixed areas of limestone, shale, and sand¬ stone and some igneous rocks. It left a blanket of tills that often vary from moraine to moraine. Where the moraines are closely spaced, the soils developed from these tills often vary widely in permeability over short distances. The medium-textured tills, especially loams and silt loams, are good soil parent materials. The coarser or finer the texture, the less desirable the till as a parent material. When they were deposited, the tills were cal¬ careous and well supplied with plant nutrients except nitrogen and possibly phosphorus. In general, the tills have considerably lower available-water holding capac¬ ities and higher bulk densities and are more compact than loess. Alluvium includes the sediments recently deposited by streams on their floodplains. It is the main soil parent material in soil region XV, which occupies about 12 per¬ cent of the state, and is indicated in brown in Figure 2. •Alluvium occurs throughout Illinois in stream valleys. It is most extensive in southern Illinois because that region is more dissected and has older, more mature, and wider valleys. Many of the small valleys or alluvial areas in the state are too small to be shown on the Gen¬ eral Soil Map. Alluvial sediments in Illinois vary in reaction from acid to calcareous, in color from light to dark, and in texture from sands to clays. The acid alluvial sediments occur in southern Illinois, and the slightly acid to neutral and the calcareous sediments occur primarily in the central and northern parts of Illinois, although they are found throughout the state. Medium-textured alluvial sedi¬ ments predominate. The smaller stream valleys usually have silty or loamy sediments, and the moderately fine- and fine-textured sediments are found mainly in the larger bottomlands along the Mississippi, Illinois, Wabash, and Ohio rivers. Soils formed from bedrock weathered in place are of minor extent in Illinois. These soils are most important on steep slopes in the unglaciated sections of north¬ western Illinois and in extreme southern Illinois. Often the residual soils have been eroded in the geologic past and now have upper horizons that formed in later de¬ posited materials. Soils formed from thin loess, till, or outwash on various kinds of bedrock are most extensive in .soil parent material regions XIII and XIV, which occupy about 5 percent of the state. These two regions are indicated in yellow in Figure 2. Many of the ridge- tops and more level areas of regions XIII and XIV have moderately thick to thick loess soil parent materials, but are too narrow to show in Figure 2. Organic materials or the remains of plants are also of minor importance as soil parent materials in Illinois. They occur mainly in extreme northeastern Illinois in soil region XVI, which occupies only about 0.2 percent of the state; a few areas are found in some of the major river valleys. Soil region X\T is not shown in Figure 2 because the individual areas of this region are too small. However, these areas are shown on the General Soil Map at the back of this publication. Mucks and peats are the main soils formed from the decay of plant remains. Both are very high in organic matter. Muck is more decom¬ posed than peat. Soils of Illinois 69 Climate Climate plays an important role in soil development, and is responsible for many of the differences between soils. It largely determines the type of weathering that takes place in an area and also influences the type of vegetation that grows on soils. The humid, temperate climate of Illinois is conducive to the breakdown of soil minerals, the formation of clay, and the translocation or movement of these materials downward in the soil pro¬ file. Materials such as clay tend to be removed from A horizons and accumulate in B horizons. This is the reason why B horizons or subsoils are usually heavier textured than horizons in soils that developed in uni¬ form parent materials. Temperature and rainfall are the major components of climate, and their effects are often closely related. In general, both clay formation and clay destruction in¬ crease as temperature and rainfall increase. Current evidence indicates that a zone of maximum clay accumu¬ lation exists in the soils of central Illinois. In northern Illinois, the rate of clay formation is lower than in the central part of the state. In southern Illinois, the rate of clay destruction and movement downward from the B horizon appear to be greater than the current rate of clay accumulation. These relationships are likely to change with geologic time and advanced weathering of soils. In general, chemical weathering is more intense in humid, warm climates and physical weathering is more impor¬ tant in dry climates. The climate of Illinois during the development of our soils is difficult to characterize. The best evidence seems to indicate that there were significant fluctuations in temperature and rainfall. For some time during and after the retreat of the last Wisconsinan glacial ice from Illinois, some 12,000 years ago, the climate in Illinois was cooler and wetter than at present. A rather warm, dry period 4,000 to 6,000 years ago led to an expansion of grassland in the state. Since that time, our climate seems to have remained similar to that of today. The present climate in the state is of the continental type, with hot summers and cold winters. The average annual temperature ranges from about 47° F. in the north to 59° F. in the south (Figure 4). January is normally the coldest month; the mean temperature ranges from about 22° F. in the north to 36° F. in the south. The mean temperature in July (usually the hottest month) ranges from about 73° F. in the north to 80° F. in the south. The latitudinal extent of the state from 37 to 42.5 degrees north is largely responsible for these temperature variations. The average annual precipitation in Illinois ranges from about 32 inches in the north to 47 inches in the south (Figure 5). Although total precipitation is greatest in southern Illinois, about the same amount falls during the growing season (April to September) throughout the state. Because southern Illinois is closer to the Gulf of Mexico and has more cyclonic activity in winter, it has more winter and early spring precipitation than the remainder of the state. The average number of frost-free days in Illinois ranges from less than 160 in the north to more than 200 in the south (Figure 6). Although the growing season is shorter in northern Illinois, frost damage is usually not a serious problem because crop varieties and corn hybrids with shorter maturity periods are used in that part of the state. In the southern one-third of the state, where the aver¬ age growing season is more than about 180 days, double cropping of soybeans following wheat has been widely practiced in recent years. If there is enough moisture to germinate soybeans planted directly in wheat stubble during June and July, the growing season is usually long enough to mature the second-crop soybeans. Yields of the second-crop soybeans are rather variable, but add to net farm income in most years. Figure 4. Average annual temperature (degrees Fahrenheit) in Illinois, 1931 to 1960. (Data from U.S. Weather Bureau.) 70 Bulletin 778 Vegetation Soil development is influenced by the native vegetation under which the soils formed. The two main types of native vegetation that influenced Illinois soils are grass or prairie and trees or forest. Although the climate of Illinois is conducive to the growth of forest, about 55 percent of the state had prairie vegetation during and for some time before settlement (Figure 7). The prairie vegetation is believed to be a relict from the warm, dry period that prevailed some 4,000 to 6,000 years ago. In central and northern Illinois, where prairie vegetation predominated, forests were largely confined to the better drained, more rolling areas bordering stream valleys. Soils fonned under grass are normally dark colored and high in organic matter content unless they are highly weathered and strongly developed. Soils formed under forest in Illinois are light colored and usually low in organic matter content. Similar types of soil weathering occur under prairie and forest vegetation, but soil devel¬ opment is more intense under forest in climates such as that of Illinois. .Although the largest area of the soils of Illinois fonned under grass, it is evident that at the time of settlement the forests were encroaching upon the prairies. Along the prairie-forest border, it is common to Figure 5. Average annual precipitation (inches) in Illinois, 1931 to 1960. (Data from U.S. Weather Bureau.) find moderately dark-colored soils under forest. In these areas, the forest has not been present for sufficient time to entirely change soil features imparted by a previous grass or prairie vegetation. Vegetation is not the only living matter that influences soil development. Soil development is also affected by animal life such as earthworms, crayfish, ground squirrels and other burrowing animals, and various insects. These creatures incorporate organic matter into the soil and mix soils to varying depths and degrees. Relief and Drainage In most parent materials under a given climate, the moisture status of soils is controlled largely by relief, which includes elevation, topography or lay and slope of the land, and water table levels. As previously mentioned, the mean elevation of Illinois is about 600 feet above sea level. The highest and most rolling areas are in north¬ western and southern Illinois, and the counties with the highest percentages of nearly level land are in the central part of the state. Topography influences the amount of infiltration, runoff and drainage water, and erosion. The amount of moisture in the soil while it is devel¬ oping affects the rate of weathering and the development Soils of Illinois 71 Native prairie vegetation I I Native forest vegetation Figure 7. Native vegetation in Illinois. of soil colors. Soil colors are a reflection of the moisture status of the soil during its development. Well-drained soils have uniformly brownish or yellowish brown sub¬ soils; poorly drained soils have grayish subsoils; and somewhat poorly drained soils have mottled yellowish, brownish, and grayish subsoils. Water table levels are usually highest in depressional and nearly level, poorly drained areas and lowest in rough or rolling, well-drained areas. In uniform soil materials such as loess, differences in natural soil drainage are usually closely associated with slope. The shape, direction, and length of slope also affect soil development. Convex slopes tend to be drier than concave slopes because they usually shed water faster. Slopes facing south are drier than slopes facing north because those facing south are more directly ex¬ posed to the sun. On long slopes, wash from the upper portion is often added as colluvial material to the lower portion. Time The effect of time on soil development cannot be measured precisely in years because the time required for a soil to develop depends upon the other factors that in¬ fluence soil formation. For example, in humid climates that support good growth of vegetation, soils develop more rapidly than in dry climates. The pace of .soil devel¬ opment is also determined by the parent material. Plant nutrients and materials such as carbonates leach more rapidly in coarse-textured, peiTneable parent materials than in fine-textured, slowly permeable materials; an acid soil develops much faster in materials that are low in limestone than in those that are high in limestone. Topography can also have a marked effect on the time required for a soil to develop. On steep slopes, where erosion often removes the soil nearly as fast as it is formed, soils may be very thin and youthful or weakly developed, even if they have been exposed to weathering for very long periods. On stable landscapes, however, soils tend to be more strongly developed and more highly leached, and their horizons become more differentiated the longer they are exposed to weathering. Most of the soil parent materials of Illinois, with the exception of rock residuum, which is older, were de¬ posited during Pleistocene or glacial times. The Peorian loess, most of the outwash, and the glacial tills of the northeastern part of the state were deposited during the Wisconsinan glacial stage, which receded from Illinois some 12,000 years ago. Most of the soils of Illinois de¬ veloped during and since Wisconsinan times. MAJOR SOIL ORDERS IN ILLINOIS Soils may be grouped in a variety of ways, depending upon the characteristics on which the groupings are based and on the uses to be made of the groups. In soil classification, soils are grouped on the basis of properties at various levels or categories. The lowest and most de¬ tailed level is the individual kind of soil or soil series that is given a place name, such as Mu.scatine, Flanagan, Elliott, or Cisne. The soil order is the highest and most generalized level. There are 10 orders or major soil groups in the soil classification system; they are believed to include all of the soils of the world. The soil orders are separated from one another on the basis of several critical horizons that give a key to the main soil-forming processes; the absence of these horizons indicates a lack of development. Soils that have undergone similar development and have similar kinds of horizons tend to be grouped in the same order. For example, most (but not all) soils with thick dark-colored A horizons are included in the Mollisol order. Soils that lack distinctive horizons, such as the 72 Bulletin 778 light-colored, recently deposited alluvial soils, are placed in the Entisol order. Between the soil order and soil series, there are four other categories of soils: suborders or subdivisions of the orders, great groups, subgroups, and soil families. The soil family is the category immediately above the soil series. Only five of the 10 soil orders are important in Illi¬ nois: the Mollisols, Alfisols, Entisols, Inceptisols, and Histosols. The Mollisols and the Alfisols are by far the most extensive in the state. The distribution and extent of three of the five major soil groups or soil orders in Illinois (the Mollisols, .Alfisols, and Entisols) are shown in Eigure 8. Areas of the Inceptisols and Histosols are generally too small to be shown at the scale used in Eigure 8. Mollisols The Mollisols in Illinois are the dark-colored soils formed under grass, although some of the ones on the major river floodplains had a forest or mixed forest and grass cover at the time of settlement. The thick, dark surface layer of the Mollisols was formed by the de¬ composition of underground vegetative remains con¬ sisting mostly of roots but also including surface vegeta¬ tion that had been incorporated into the soil by animal life such as earthworms and various burrowing animals. Eor a soil to be classified as a Mollisol, its surface layer must not only be dark colored and have an average of more than 1 percent organic matter throughout, it must also be at least 10 inches thick (unless the total soil is very thin) and have sufficient soil structure so that it is not massive and hard or very hard when dry. In addi¬ tion, the dark-colored layer and the B horizon must have a base saturation of more than 50 percent with calcium as the predominant base. The Mollisols vary widely in texture, permeability, degree of subsoil development, and many other properties. As shown in Figure 8, Mollisols are most extensive in central and northern Illinois. In southern Illinois, they are confined largely to the floodplains and some of the terraces of the major rivers. The Mollisols shown in the river valleys in Figure 8 include some areas of Entisols and Inceptisols that were too small to be shown sepa¬ rately on the map. Mollisols occupy about 49 percent of the state’s land area. Alfisols In Illinois, the Alfisols are generally the light-colored soils that formed under forest. Some major exceptions are Cowden and the related soils of soil association 5 and Cisne and the related soils of association 6. Although □ Mollisol order Alfisol order Entisol order Figure 8. Major soil orders in Illinois. both soil groups formed under grass, their surface soil layers are too thin, too light colored, or too low in base saturation to be grouped with the Mollisols. Low base saturation in the B horizon may also exclude some of these soils from the Mollisols. The Alfisols either have light-colored surface layers or dark-colored surface layers that are only a few inches thick. For a soil to be classified as an Alfisol, its surface layer must have an average of less than 1 percent organic matter content throughout, and it must have a recogniz¬ able B horizon of clay accumulation that has a base saturation of more than 35 percent at a depth of 50 inches below the top of the B horizon. The Alfisols predominate in southern Illinois, although they are present throughout the state (Figure 8). In central and northern Illinois, they are confined largely to the more rolling, better drained sites bordering stream valleys or to the drier morainic positions. Alfisols occupy about 46 percent of the state. Soils of Illinois 73 Entisols In Illinois, the Entisols include most of the light- colored, recently deposited alluvial soils in the southern and western parts of the state. These soils have not been in place long enough to develop recognizable horizons, although they may have a darkened plow layer (Figure 7). This order also includes a few very sandy soils that lack sufficient weatherable minerals to form recognizable horizons. The light-colored sandy Entisols in h'igure 12 are located mainly in central and northern Illinois and near the Mollisols in the Wabash River valley. Although some Entisols may have buried surface horizons of former soils, these soils are classified as Entisols only if recent alluvium has accumulated to a depth of more than 20 inches over the former soil. The Entisols occur along streams that receive sedi¬ ments from flooding and in very sandy areas where soils such as Plainfield predominate. A few Entisols, such as Hamburg and Bold, occur on steep slopes where geologic erosion has limited soil development. Entisols are estimated to occupy about 3’A percent of the state. Inceptisols The Inceptisols include soils that have weakly devel¬ oped horizons. They lack the thick, dark-colored surface layer of the Mollisols and the B horizon of clay accumu¬ lation of the .\lfisols. They differ from the Entisols in having some recognizable horizons or showing evidence of the beginning of horizon development. Changes in horizon development may have taken place over rela¬ tively short periods. Processes such as leaching of carbo¬ nates, oxidation or reduction of iron compounds, and formation of structure have taken place in these soils. The Incepti.sols of Illinois include only about a dozen soil series. Some are nearly level stream terrace or bot¬ tomland soils, but most are steep soils in which geologic erosion has allowed only weak development of soil horizons. Inceptisols are estimated to occupy about l ‘/2 percent of Illinois. The Inceptisols are included with the Entisol areas in the bottomlands and with the Alfisols in the ujjlands in Figure 8. Because areas of Inceptisols are often small or narrow, they could not be shown scj^aratcly. Histosols The Plistosols include the organic soils — the peats and mucks — which formed from the remains of plants. Mucks are more thoroughly decomposed than peats. These soils commonly occur in low-lying areas, remain wet unless artificially drained, and contain high amounts of organic matter. The exact amount of organic matter in the Histosols varies with the amount of clay in any mineral matter that may be mixed with the organic remains. In general, the Histosols contain much more organic matter than the Mollisols in Illinois. The organic matter content of Histosols is generally more than 20 percent. The Histosols occur mainly in extreme northeastern Illinois, although some scattered areas are present in various counties in the northern half of the state. Areas of Histosols are too small to be shown in Figure 8. They are estimated to occupy about one-fourth of 1 percent of the state. PROGRESS OF SOIL SURVEYS IN ILLINOIS For most users, the two essential elements of a soil survey are (1) the soil map, which shows the location and extent of the various soil types on a suitable base map of the area; and (2) the soil report, which de¬ scribes and gives the properties of the soils and their characteristics for various purposes and uses such as agriculture, engineering, and woodland. Soil surveys have been made in Illinois since 1902. Over the years, soil survey techniques and skills have been developed and improved, resulting in more accu¬ rate, larger, and more detailed soil maps and more com¬ prehensive soil reports. The curi'ent status of soil survey maps and reports for Illinois is shown in Figure 9. Forty-five counties have modern published soil surveys. The soil maps in these surveys have an aerial photo base and indicate the soil type, slope, and degree of erosion. The scale of most of these surveys is 4 inches to 1 mile. Surveys for 12 more counties are essentially complete and scheduled to be published soon. Modern surveys are in progress in 20 other counties, but none is currently being conducted in the remaining 25 counties. Some of these 25 counties have older surveys with soil maps that are small and considerably out of date. General information on soils in these counties is available through the Soil Conservation Service, USD.\, or the Department of Agronomy, Uni¬ versity of Illinois at Urbana-Champaign. 74 Bulletin 778 Counties with Modern Published Soil Surveys Published soil reports are listed below with their num¬ bers in the Illinois Agricultural Experiment Station series as well as the county name and year of publication. Pub¬ lished reports can be obtained from the Office of Agricul¬ tural Publications, 47 Mumford Hall, 1301 W. Gregory Drive, or the Department of Agronomy, W-201 Turner Hall, 1102 S. Goodwin Avenue, both at the University of Illinois, Urbana, Illinois 61801, or from the local district office of the Soil Conservation Service, USD.A, or local county Extension office. 101 Adams (1979) 85 Alexander-Pulaski (1968) 107 Boone-Winnebago (1980) 98 Carroll ( 1975) 114 Champaign (1982) 103 Clark (1979) 108 Cook-DuPage (1979) 96 DeKalb (1978) 89 Douglas (1971) 108 DuPage-Cook (1979) 90 Edwards-Richland (1972) 87 Gallatin (1969) 93 Greene (1974) 112 Grundy (1980) 94 Hardin-Popc-Massac (1975) 77 Henderson (1956) 115 Iroquois (1982) 106 Jackson (1979) 84 Jersey (1966) 82 Johnson (1964) 109 Kane (1979) 105 Kankakee (1979) 95 Kendall (1978) 88 Lake (1970) 91 LaSalle ( 1972) 78 Lawrence (1956) 92 Logan (1974) 94 Massac-Pope-Hardin (1975) 81 McHenry (1965) 76 Menard (1953) 86 Montgomery (1969) 113 Ogle (1980) 94 Pope-Hardin-Massac (1975) 85 Pulaski-Alexander (1968) 90 Richland-Edwards (1972) 97 Rock Island (1977) 102 Saline (1978) 111 Sangamon (1980) 104 St. Clair (1978) 99 Stephenson (1976) 110 Union (1979) 83 Wabash (1964) 80 Will (1962) 79 Williamson (1959) 107 Winnebago-Boone (1980) Counties with Completed Surveys to be Published Soon Bond Brown Hamilton Plenry Knox Lee Madison Monroe Morgan Perry Randolph Scott Counties with Soil Surveys in Progress Bureau Calhoun Cass Christian Coles DeWitt Effingham Ford Jasper Macon Macoupin Marion Mercer Peoria Piatt Shelby Tazewell Vermilion Wayne Whiteside Counties in Need of Modern Soil Surveys Some counties have older surveys. Most of these sur¬ veys are considerably out of date; those indicated with an asterisk(*) are no longer available. 1 Clay (1911) 28 Mason (1924) 57 Clinton (1936) 7 McDonough (1913) Crawford 10 McLean (1915) 69 Cumberland (1940) 2 Moultrie (1911) 15 Edgar (1917) 11 Pike (1915) 52 Fayette (1932) 60 Putnam (1937) Franklin 56 Schuyler (1934) 51 Fulton (1932) 64 Stark (1939) 27 Hancock (1924) *70 Warren (1941) Jefferson 58 Washington (1937) Jo Daviess White *72 Livingston (1949) 36 Woodford (1927) 59 Marshall (1937) Modern published soil survey Modern soil survey completed — to be published Modern soil survey being con¬ ducted, with date for completion set Older soil surveys published before 1952 j I No modern soil survey being conducted and no old published survey available Figure 9. Statu.s of soil surv'ey maps in Illinois. Soils of Illinois 75 Alphabetical List of Illinois Soils (Number, Series, Family, Line in Soil Key, and Soil Association Area) No. Series Family Line in Soil Key Soil associa¬ tion area 98 Ade Coarse-loamy, mixed, mesic Psammentic Argiudolls 185 22 777 Adrian Sandv or sandy-skeletal, mixed, euic, mesic Terric Medisaprists 305 25 670 Aholt Very-fine, montmorillonitic (calcareous), mesic Vertic Haplaquolls 144 19 308 Alford Fine-silty, mixed, mesic Typic Hapludalfs 17, 228, 243 33, 52, 53 306 Allison Fine-silty, mixed, mesic Cumulic Hapludolls 285 24 131 Alvin Coarse-loamy, mixed, mesic Typic Hapludalfs 193 50 131V Alvin, thick A Coarse-loamy, mixed, mesic Typic Hapludalfs 194 50 302 Ambraw Fine-loamy, mixed, mesic Fluvaquentic Haplaquolls 267 24 293 Andres Fine-loamy, mixed, mesic Aquic Argiudolls 116 15 365 Aptakisic Fine-silty, mixed, mesic Aerie Ochraqualfs 87 41 78 Arenzville Coarse-silty, mixed, nonacid, mesic Typic Udifluvents 274 57 227 Argyle Fine-loamy, mixed, mesic Mollic Hapludalfs 55 37 597 Armiesburg Fine-silty, mixed, mesic Fluventic Hapludolls 284 24 411 Ashdale Fine-silty, mixed, mesic Typic Argiudolls 212 23 232 Ashkum Fine, mixed, mesic Typic Haplaquolls 112 14 259 Assumption Fine-silty, mixed, mesic Typic Argiudolls 45 2, 3, 4 661 Atkinson Fine-loamy, mixed, mesic Typic Argiudolls 220 23 7 Atlas Fine, montmorillonitic, mesic, sloping Aerie Ochraqualfs 41 32, 33, 34, 35, 36 61 Atterberry Fine-silty, mixed, mesic Udollic Ochraqualfs 12 32 14 Ava Fine-silty, mixed, mesic Typic Fragiudalfs 33 36 204 Ayr Fine-loamy, mixed, mesic Typic Argiudolls 106 12, 13 768 Backbone Coarse-loamy, mixed, mesic Mollic Hapludalfs 216 51 787 Banlic Coarse-silty, mixed, nonacid, mesic Aerie Haplaquepts 273 57 443 Barrington Fine-silty, mixed, mesic Typic Argiudolls 85 11 105 Batavia Fine-silty, mixed, mesic Mollic Hapludalfs 73 41 599 Baxter Fine, mixed, mesic Typic Paleudalfs 224 52 472 Baylis Fine-silty, mixed, mesic Typic Paleudalfs 226 52 188 Beardstown Fine-loamy, mixed, mesic Udollic Ochraqualfs 176 21 691 Beasley Fine, mixed, mesic Typic Hapludalfs 255 54, 55 70 Beaucoup Fine-silty, mixed, mesic Fluvaquentic Haplaquolls 284 24 598 Bedford Fine-silty, mixed, mesic Typic Fragiudults 227 52 298 Beecher Fine, illitic, mesic Udollic Ochraqualfs 113 44 382 Belknap Coarse-silty, mixed, acid, mesic Aerie Fluvaquents 272 57 955, 986 Berks Loamy-skeletal, mixed, mesic Typic Dystrochrepts 230 53, 54, 55 332 Billett Coarse-loamy, mixed, mesic Mollic Hapludalfs 189 50 334 Birds Fine-silty, mixed, nonacid, mesic Typic Fluvaquents 271 57 233 Birkbeck Fine-silty, mixed, mesic Typic Hapludalfs 69 39 603 Blackoar Fine-silty, mixed, mesic Fluvaquentic Haplaquolls 281 24 5 Blair Fine-loamy, mixed, mesic Aquic Hapludalfs 39 31, 32, 33, 34, 35, 36 53 Bloomfield Coarse-loamy, mixed, mesic Psammentic Hapludalfs 186 50 23 Blount Fine, illitic, mesic Aerie Ochraqualfs 114 44 13 Bluford Fine, montmorillonitic, mesic Aerie Ochraqualfs 33 36 471 Bodine Loamy-skeletal, siliceous, thermic Typic Paleudults 223 52 35 Bold Coarse-silty, mixed (calcareous), mesic Typic Udorthents 16 31, 32, 33 493 Bonfield Loamy-skeletal, mixed, mesic Aquic Hapludolls 215 23 108 Bonnie Fine-silty, mixed, acid, mesic Typic Fluvaquents 272 57 457 Booker Very-fine, montmorillonitic, mesic Vertic Haplaquolls 145, 301 19, 24 397 Boone Mesic, uncoated Typic Quartzipsamments 229 56 589 Bowdre Clayey over loamy, montmorillonitic, thermic Fluvaquentic Hapludolls 292 24 792 Bowes Fine-silty, mixed, mesic Mollic Hapludalfs 89 41 706 Boyer Coarse-loamy, mixed, mesic Typic Hapludalfs 165 48 956 Brandon Fine-silty, mixed, thermic Typic Hapludults 246 54 149 Brenton Fine-silty, mixed, mesic Aquic Argiudolls 82 1 1 684 Broadwell Fine-silty, mixed, mesic Typic Argiudolls 61 8 136 Brooklyn Fine, montmorillonitic, mesic Mollic Albaqualfs 80 11 235 Bryce Fine, mixed, mesic Typic Haplaquolls 118 16 76 Bulletin 778 Alphabetical List of Illinois Soils (continued) No. Series Family Line in Soil Key Soil associa¬ tion area 444 Bungay Fine, mixed, nonacid, mesic Typic Haplaquepts 294 46, 57 961 Burkhardt Sandy, mixed, mesic Typic Hapludolls 149 20 427 Burnside Loamy-skeletal, mixed, acid, mesic Typic Udifluvents 258 57 590 Cairo Clayey over sandy or sandy-skeletal, montmorillonitic, thermic Vertic Haplaquolls 290 24 746 Calamine Fine, mixed, mesic Typic Argiaquolls 250, 252 56 400 Calco Fine-silty, mixed (calcareous), mesic Cumulic Haplaquolls 288 24 134 Camden Fine-silty, mixed, mesic Typic Hapludalfs 84 41 347 Canisteo Fine-loamy, mixed (calcareous), mesic Typic Haplaquolls 76 11 422 Cape Fine, montmorillonitic, acid, mesic Typic Fluvaquents 293 57 286 Carmi Coarse-loamy, mixed, mesic Typic Hapludolls 153 20 323 Casco Fine-loamy over sandy or sandy-skeletal, mixed, mesic Typic Hapludalfs 155 48 171 Catlin Fine-silty, mixed, mesic Typic Argiudolls 67 9 315 Channahon Loamy, mixed, mesic Lithic Argiudolls 199 23 241 Chatsworth Fine, illitic, mesic Typic Eutrochrepts 123 44, 45 287 Chauncey Fine, montmorillonitic, mesic Typic Argialbolls 30 6 779 Chelsea Mixed, mesic Alfic Udipsamments 184 50 282 Chute Mixed, mesic Typic Udipsamments 179 50 2 Cisne Fine, montmorillonitic, mesic Mollic Albaqualfs 29 6 147 Clarence Fine, illitic, mesic Aquic Argiudolls 124 17 257 Clarksdale Fine, montmorillonitic, mesic Udollic Ochraqualfs 21, 25 34 471 Clarksville Loamy-skeletal, siliceous, mesic Typic Paleudults 222 52 18 Clinton Fine, montmorillonitic, mesic Typic Hapludalfs 22, 26 34 660 Coatsburg Fine, montmorillonitic, mesic, sloping Typic Argiaquolls 40 4, 5, 6 428 CofFeen Coarse-silty, mixed, mesic Fluvaquentic Hapludolls 92 11 402 Colo Fine-silty, mixed, mesic Cumulic Haplaquolls 286 24 122 Colp Fine, montmorillonitic, mesic Aquic Hapludalfs 143 46 776 Comfrey Fine-loamy, mixed, mesic Cumulic Haplaquolls 266 24 495 Corwin Fine-loamy, mixed, mesic Typic Argiudolls 100 12 112 Cowden Fine, montmorillonitic, mesic Mollic Albaqualfs 27 5 764 Coyne Coarse-loamy, mixed, mesic Typic Argiudolls 129 11, 19 609 Crane Fine-loamy, mixed, mesic Aquic Argiudolls 166 20 337 Creal Fine-silty, mixed, mesic Aquic Hapludalfs 34 36 379 Dakota Fine-loamy over sandy or sandy-skeletal, mixed, mesic Typic Argiudolls 159 20 56 Dana Fine-silty, mixed, mesic Typic Argiudolls 97 12 620 Darmstadt Fine-silty, mixed, mesic Albic Natraqualfs 36 4, 5, 6 740 Darroch Fine-loamy, mixed, mesic Aquic Argiudolls 172 21 71 Darwin Fine, montmorillonitic, mesic Vertic Haplaquolls 298 24 192 Del Rey Fine, illitic, mesic Aerie Ochraqualfs 135 46 45 Denny Fine, montmorillonitic, mesic Mollic Albaqualfs 11 2, 3 262 Denrock Fine, mixed, mesic Aquic Argiudolls 138 19 417 Derinda Fine, mixed, mesic Typic Hapludalfs 251 56 87 Dickinson Coarse-loamy, mixed, mesic Typic Hapludolls 187 22 742 Dickinson, loamy sub. Coarse-loamy, mixed, mesic Typic Hapludolls 188 22 266 Disco Coarse-loamy, mixed, mesic Cumulic Hapludolls 196 22 24 Dodge Fine-silty, mixed, mesic Typic Hapludalfs 96 42 40 Dodgeville Fine-silty over clayey, mixed, mesic Typic Argiudolls 208 23 239 Dorchester Fine-silty, mixed (calcareous), mesic Typic Udifluvents 279 57 578 Dorchester, cobbly Fine-silty, mixed (calcareous), mesic Typic Udifluvents 280 57 128 Douglas Fine-silty, mixed, mesic Typic Argiudolls 50 4, 5 346 Dowagiac Fine-loamy, mixed, mesic Mollic Hapludalfs 160 48 386 Downs Fine-silty, mixed, mesic Mollic Hapludalfs 12, 21, 25 32, 34 325 Dresden Fine-loamy over sandy or sandy-skeletal, mixed, mesic Mollic Hapludalfs 157 48 152 Drummer Fine-silty, mixed, mesic Typic Haplaquolls 67, 72, 82, 94, 97 9, 11, 12 Soils of Illinois 77 Alphabetical List of Illinois Soils (continued) No. Series Family Line in Soil Key Soil associa¬ tion area 75 Drury Fine-silty, mixed, mesic Dystric Eutrochrepts 93 41 29 Dubuque Fine-silty, mixed, mesic Typic Hapludalfs 211 51 505 Dunbarton Clayey, montmorillonitic, mesic Lithic Hapludalfs 203 51 511 Dunbarton, cher. Clayey, montmorillonitic, mesic Lithic Hapludalfs 204 51 321 Du Page Fine-loamy, mixed, mesic Cumulic Hapludolls 265 24 180 Dupo Coarse-silty over clayey, mixed, nonacid, mesic Aquic Udiflu- vents 276 57 416 Durand Fine-loamy, mixed, mesic Typic Argiudolls 54 7 48 Ebbert Fine-silty, mixed, mesic Argiaquic Argialbolls 31 6 272 Edgington Fine-silty, mixed, mesic Argiaquic Argialbolls 9 1, 2 249 Edinburg Fine, montmorillonitic, mesic Typic Argiaquolls 19 3 769 Edmund Clayey, montmorillonitic, mesic Lithic Argiudolls 202 23 312 Edwards Marly, euic, mesic Limnic Medisaprist 307 25 198 Elburn Fine-silty, mixed, mesic Aquic Argiudolls 72 11 119 Elco Fine-silty, mixed, mesic Typic Hapludalfs 46 32, 33, 34 264 El Dara Fine-loamy, mixed, mesic Typic Hapludalfs 197 34 547 Eleroy Fine-silty, mixed, mesic Typic Hapludalfs 254 56 761 Eleva Coarse-loamy, mixed, mesic Typic Hapludalfs 232 56 567 Elkhart Fine-silty, mixed, mesic Typic Argiudolls 20 3 146 Elliott Fine, illitic, mesic Aquic Argiudolls 112 14 137 Ellison Fine-loamy over sandy or sandy-skeletal, mixed, mesic Typic Hapludalfs 161 48 475 Elsah Loamy-skeletal, mixed, nonacid, mesic Typic Udifluvents 259 57 469 Emma Fine-silty, mixed, mesic Typic Dystrochrepts 178 49 516 Faxon Fine-loamy, mixed, mesic Typic Haplaquolls 219 23 280 Fayette Fine-silty, mixed, mesic Typic Hapludalfs 13 32 380 Fieldon Coarse-loamy, mixed (calcareous), mesic Typic Haplaquolls 164 20 496 Fincastle Fine-silty, mixed, mesic Aerie Ochraqualfs 99 42 6 Fishhook Fine, montmorillonitic, mesic Aquic Hapludalfs 44 32, 34 419 Flagg Fine-silty, mixed, mesic Typic Hapludalfs 60 37 783 Flagler Coarse-loamy, mixed, mesic Typic Hapludolls 152 20 154 Flanagan Fine, montmorillonitic, mesic Aquic Argiudolls 67 9 327 Fox Fine-loamy over sandy or sandy-skeletal, mixed, mesic Typic Hapludalfs 158 48 320 Frankfort Fine, illitic, mesic Udollic Ochraqualfs 119, 125 45 781 Friesland Fine-loamy, mixed, mesic Typic Argiudolls 170 21 786 Frondorf Fine-loamy, mixed, mesic Ultic Hapludalfs 237 35, 36 591 Fults Fine, montmorillonitic, mesic Vertic Haplaquolls 289 24 413 Gale Fine-silty over sandy or sandy-skeletal, mixed, mesic Typic Hapludalfs 238 56 431 Genesee Fine-loamy, mixed, nonacid, mesic Typic Udifluvents 264 57 201 Gilford Coarse-loamy, mixed, mesic Typic Haplaquolls 187 22 460 Ginat Fine-silty, mixed, mesic Typic Fragiaqualfs 177 49 162 Gorham Fine-silty, mixed, mesic Fluvaquentic Haplaquolls 287 24 551 Gosport Fine, illitic, mesic Typic Dystrochrepts 249 56 606 Goss Clayey-skeletal, mixed, mesic Typic Paleudalfs 225 52 513 Granby Sandy, mixed, mesic Typic Haplaquolls 180 22 301 Grantsburg Fine-silty, mixed, mesic Typic Fragiudalfs 248 55 698 Grays Fine-silty, mixed, mesic Mollic Hapludalfs 86 41 780 Grellton Fine-loamy, mixed, mesic Typic Hapludalfs 171 49 363 Griswold Fine-loamy, mixed, mesic Typic Argiudolls 108 13 30 Hamburg Coarse-silty, mixed (calcareous), mesic Typic Udorthents 15 31, 32, 33 484 Harco Fine-silty, mixed, mesic Aquic Argiudolls 131 18 67 Harpster Fine-silty, mixed, mesic Typic Calciaquolls 10, 75 2, 3, 9, 11 127 Harrison Fine-silty, mixed, mesic (Aquic) Typic Argiudolls 50 4, 5 244 Hartsburg Fine-silty, mixed, mesic Typic Haplaquolls 20 3 344 Harvard Fine-silty, mixed, mesic Mollic Hapludalfs 83 41 252 Harvel Fine-silty, mixed, mesic Typic Haplaquolls 24 4 78 Bulletin 778 Alphabetical List of Illinois Soils (continued) No. Series Family Line in Soil Key Soil associa¬ tion area 771 Hayfield Fine-loamy over sandy or sandy-skeletal, mixed, mesic Aquollic 163 48 Hapludalfs 331 Haymond Coarse-silty, mixed, nonacid, mesic Typic Udifluvents 271 57 25 Hennepin Fine-loamy, mixed, mesic Typic Eutrochrepts 105 39, 42, 43 62 Herbert Fine-silty, mixed, mesic Udollic Ochraqualfs 95 42 46 Herrick Fine, montmorillonitic, mesic Aquic Argiudolls 23 4 390 Hesch Coarse-loamy, mixed, mesic Typic Argiudolls 233 56 537 Hesch gray subs. Coarse-loamy, mixed, mesic Typic Haplaquolls 233 56 389 Hesch, thin Sandy, mixed, mesic Lithic Hapludolls 234 56 8 Hickory Fine-loamy, mixed, mesic Typic Hapludalfs 39 31, 32, 33, 34, 35, 36 556 High Gap Fine-loamy, mixed, mesic Typic Hapludalfs 236 56 506 Hitt Fine-loamy, mixed, mesic Typic Argiudolls 205 23 326 Homer Fine-loamy over sandy or sandy-skeletal, mixed, mesic Aerie 158 48 Ochraqualfs 354 Hononegah Sandy, mixed, mesic Entic Hapludolls 150 20 172 Hoopeston Coarse-loamy, mixed, mesic Aquic Hapludolls 187 22 214 Hosmer Eine-silty, mixed, mesic Typic Eragiudalfs 28, 244 35, 54 103 Houghton muck Euic, mesic Typic Medisaprists 303 25 97 Houghton peat Euic, mesic Hemic Medisaprists 302 25 3 Hoyleton Eine, montmorillonitic, mesic Aquollic Hapludalfs 29 6 120 Huey Eine-silty, mixed, mesic Typic Natraqualfs 36 4, 5, 6 600 Huntington Eine-silty, mixed, mesic Eluventic Hapludolls 281 24 77 Huntsville Eine-silty, mixed, mesic Cumulic Hapludolls 282 24 338 Hurst Eine, montmorillonitic, mesic Aerie Ochraqualfs 143 46 307 Iona Fine-silty, mixed, mesic Typic Hapludalfs 14 31, 32, 33 43 Ipava Fine, montmorillonitic, mesic Aquic Argiudolls 18 3 454 Iva Fine-silty, mixed, mesic (Typic) Aerie Ochraqualfs 17, 228, 243 33, 52, 53 85 Jacob Very-fine, montmorillonitic, acid, mesic Vertic Haplaquepts 300 57 440 Jasper Fine-loamy, mixed, mesic Typic Argiudolls 172 21 314 Joliet Loamy, mixed, mesic Lithic Haplaquolls 199 23 763 Joslin Fine-loamy, mixed, mesic Typic Argiudolls 130 11, 19 275 Joy Fine-silty, mixed, mesic Aquic Hapludolls 1 1 28 Jules Coarse-silty, mixed (calcareous), mesic Typic Lfdifluvents 270 57 782 Juneau Coarse-silty, mixed, nonacid, mesic Typic Udifluvents 275 57 343 Kane Fine-loamy over sandy or sandy-skeletal, mixed, mesic Aquic 156 20 Argiudolls 494 Kankakee Loamy-skeletal, mixed, mesic Typic Hapludolls 215 23 426 Karnak Fine, montmorillonitic, nonacid, mesic Vertic Haplaquepts 295 57 421 Kell Fine-silty, mixed, mesic Typic Hapludalfs 239 36 470 Keller Fine, montmorillonitic, mesic Aquic Argiudolls 43 2, 3, 4 546 Keltner Fine-silty, mixed, mesic Typic Argiudolls 252 56 242 Kendall Fine-silty, mixed, mesic Aerie Ochraqualfs 74 41 17 Keomah Fine, montmorillonitic, mesic Aerie Ochraqualfs 22, 26 34 554 Kernan Fine, montmorillonitic, mesic Aerie Ochraqualfs 71 45 361 Kidder Fine-loamy, mixed, mesic Typic Hapludalfs 109 43 191 Knight Fine-silty, mixed, mesic Argiaquic Argialbolls 81 11 102 La Hogue Fine-loamy, mixed, mesic Aquic Argiudolls 175 21 175 Lamont Coarse-loamy, mixed, mesic Typic Hapludalfs 190 50 304 Landes Coarse-loamy, mixed, mesic Fluventic Hapludolls 261 24 60 La Rose Fine-loamy, mixed, mesic Typic Argiudolls 103 12, 13 647 Lawler Fine-loamy over sandy or sandy-skeletal, mixed, mesic Aquic 162 20 Hapludolls 683 Lawndale Fine-silty, mixed, mesic Aquic Argiudolls 61 8 451 Lawson Fine-silty, mixed, mesic Cumulic Hapludolls 282 24 628 Lax Fine-silty, siliceous, thermic Typic Fragiudults 245 54 196 Lemond Coarse-loamy, mixed (calcareous), mesic Typic Haplaquolls 77 11 210 Lena Euic, mesic Typic Medisaprists 304 25 Soils of Illinois 79 Alphabetical List of Illinois Soils (continued) No. Series Family Line in Soil Key Soil associa¬ tion area 59 Lisbon Fine-silty, mixed, mesic Aquic Argiudolls 94 12 81 Littleton Fine-silty, mixed, mesic Cumulic Hapludolls 91 11 265 Lomax Coarse-loamy, mixed, mesic Cumulic Hapludolls 195 22 394 Longlois Fine-loamy, mixed, mesic Mollic Hapludalfs 167 48 572 Loran Fine-silty, mixed, mesic Aquic Argiudolls 252 56 318 Lorenzo Fine-loamy over sandy or sandy-skeletal, mixed, mesic Typic Argiudolls 154 20 167 Lukin Fine-silty, mixed, mesic Typic Argialbolls 30 6 176 Marissa Fine-silty, mixed, mesic Argiaquic Argialbolls 132 46 531 Markham Fine, illitic, mesic Mollic Hapludalfs 113 44 467 Markland Fine, mixed, mesic Typic Hapludalfs 137 46 549 Marseilles Fine-silty, mixed, mesic Typic Hapludalfs 256 56 393 Marseilles, gray subs. Fine, montmorillonitic, mesic Aquic Hapludalfs 256 56 772 Marshan Fine-loamy over sandy or sandy-skeletal, mixed, mesic Typic Haplaquolls 162 20 570 Martinsville Fine-loamy, mixed, mesic Typic Hapludalfs 173 49 189 Martinton Fine, illitic, mesic Aquic Argiudolls 134 19 753 Massbach Fine-silty, mixed, mesic Mollic Hapludalfs 253 56 342 Matherton Fine-loamy over sandy or sandy-skeletal, mixed, mesic Udollic Ochraqualfs 157 48 89 Maumee Sandy, mixed, mesic Typic Haplaquolls 182 22 248 McFain Clayey over loamy, montmorillonitic, mesic Fluvaquentic Hap¬ laquolls 291 24 173 McGary Fine, mixed, mesic Aerie Ochraqualfs 137 46 310 McHenry Fine-loamy, mixed, mesic Typic Hapludalfs 111 43 682 Medway Fine-loamy, mixed, mesic Fluvaquentic Hapludolls 267 24 497 Mellott Fine-silty, mixed, mesic Mollic Hapludalfs 98 42 205 Metea Loamy, mixed, mesic Arenic Hapludalfs 107 42, 43 27 Miami Fine-loamy, mixed, mesic Typic Hapludalfs 102 42 685 Middletown Fine-silty, mixed, mesic Typic Hapludalfs 62 38 69 Milford Fine, mixed, mesic Typic Haplaquolls 134 19 187 Milroy Fine-loamy, mixed, mesic Mollic Ochraqualfs 176 21 219 Millbrook Fine-silty, mixed, mesic Udollic Ochraqualfs 83 41 82 Millington Fine-loamy, mixed (calcareous), mesic Cumulic Haplaquolls 265 24 317 Millsdale Fine, mixed, mesic Typic Argiaquolls 217 23 295 Mokena Fine-loamy, mixed, mesic Aquic Argiudolls 127 16, 17 448 Mona Fine-loamy, mixed, mesic Typic Argiudolls 127 16, 17 229 Monee Fine, illitic, mesic Mollic Ochraqualfs 121 16, 17 465 Montgomery Fine, mixed, mesic Typic Haplaquolls 136 18, 19 57 Montmorenci Fine-loamy, mixed, mesic Aquollic Hapludalfs 101 42 194 Morley Fine, illitic, mesic Typic Hapludalfs 114 44 501 Morocco Mixed, mesic Aquic Udipsamments 181 50 268 Mt. Carroll Fine-silty, mixed, mesic Mollic Hapludalfs 3 31 442 Mundelein Fine-silty, mixed, mesic Aquic Argiudolls 85 11 453 Muren Fine-silty, mixed, mesic Aquic Hapludalfs 17, 228, 243 33, 52, 53 41 Muscatine Fine-silty, mixed, mesic Aquic Hapludolls (most Muscatine in Illinois is in Aquic Argiudolls) 8 2 638 Muskego Coprogenous, euic, mesic Limnic Medisaprists 308 25 425 Muskingum Fine-loamiy, mixed, mesic Typic Dystrochrepts 235 53, 54, 55 414 Myrtle Fine-silty, mixed, mesic Mollic Hapludalfs 59 37 649 Nachusa Fine-loamy, mixed, mesic Aquic Argiudolls 42 11 592 Nameoki Fine, montmorillonitic, mesic Fluvaquentic Hapludolls 289 24 228 Nappanee Fine, illitic, mesic Aerie Ochraqualfs 120, 126 45 731 Nasset Fine-silty, mixed, mesic Mollic Hapludalfs 213 51 585 Negley Fine-loamy, mixed, mesic Typic Paleudalfs 48 33, 36 53, 34, 35, 976,977 Neotoma Loamy-skeletal, mixed, mesic Ultic Hapludalfs 231 54, 55 218 Newberry Fine-silty, mixed, mesic Mollic Ochraqualfs 32 6 928 New Glarus Fine-silty over clayey, mixed, mesic Typic Hapludalfs 209 51 80 Bulletin 778 Alphabetical List of Illinois Soils (continued) No. Series Family Line in Soil Key Soil associa¬ tion area 261 Niota Fine, mixed, mesic Mollic Albaqualfs 139 46 568 Niota, thin A 140 46 741 Oakville Mixed, mesic Typic Udipsamments 183 50 387 Ockley Fine-loamy, mixed, mesic Typic Hapludalfs 168 48 113 Oconee Fine, montmorillonitic, mesic Udollic Ochraqualfs 27 5 656 Octagon Fine-loamy, mixed, mesic Mollic Hapludalfs 101 42 490 Odell Fine-loamy, mixed, mesic Aquic Argiudolls 100 12 412 Ogle Fine-silty, mixed, mesic Typic Argiudolls 57 7 574 Ogle, sil. sub. Fine-silty, mixed, mesic Typic Argiudolls 58 7 84 Okaw Fine, montmorillonitic, mesic Typic Albaqualfs 143 46 289 Omaha Coarse-loamy, mixed, mesic Aquic Hapludolls 153 20 150 Onarga Coarse-laomy, mixed, mesic Typic Argiudolls 191 22 673 Onarga, red subs. Coarse-loamy, mixed, mesic Typic Argiudolls 192 22 752 Oneco Fine-loamy, mixed, mesic Mollic Hapludalfs 206 51 200 Orio Fine-loamy, mixed, mesic Mollic Ochraqualfs 174 21 415 Orion Coarse-silty, mixed, nonacid, mesic Aquic Udifluvents 274 57 76 Otter Fine-silty, mixed, mesic Cumulic Haplaquolls 282 24 100 Palms Loamy, mixed, euic, mesic Terric Medisaprists 306 25 429 Palsgrove Fine-silty, mixed, mesic Typic Hapludalfs 214 51 256 Pana Fine-loamy, mixed, mesic Typic Argiudolls 47 4, 5, 6 42 Papineau Fine-loamy over clayey, mixed, mesic Aquic Argiudolls 128 16, 17 15 Parke Fine-silty, mixed, mesic Ultic Hapludalfs 49 33, 34. 35. 619 Parkville Clayey over loamy, montmorillonitic, mesic Fluvaquentic Hapludolls 291 24 221 Parr Fine-loamy, mixed, mesic Typic Argiudolls 100 12 142 Patton Fine-silty, mixed, mesic Typic Haplaquolls 131 18 21 Pecatonica Fine-loamy, mixed, mesic Typic Hapludalfs 56 37 153 Pella Fine-silty, mixed, mesic Typic Haplaquolls 85, 100 9, 11, 12 330 Peotone Fine, montmorillonitic, mesic Cumulic Haplaquolls 115 9, 14 288 Petrolia Fine-silty, mixed, nonacid, mesic Typic Fluvaquents 277 57 474 Piasa Fine, montmorillonitic, mesic Typic Natralbolls 35 4, 5, 6 583 Pike Fine-silty, mixed, mesic Ultic Hapludalfs 51 33, 34, 35 159 Pillot Fine-silty over sandy or sandy-skeletal, mixed, mesic Typic Argiudolls 65 8 420 Piopolis Fine-silty, mixed, acid, mesic Typic Fluvaquents 278 57 54 Plainfield Mixed, mesic Typic Udipsamments 181 50 199 Plano Fine-silty, mixed, mesic Typic Argiudolls 72 11 240 Plattville Fine-loamy, mixed, mesic Typic Argiudolls 221 23 277 Port Byron Fine-silty, mixed, mesic Typic Hapludolls 1 1 562 Port Byron sandy sub. Fine-silty, mixed, mesic Typic Hapludolls 2 1 650 Prairieville Fine-loamy, mixed, mesic Typic Argiudolls 42 11 148 Proctor Fine-silty, mixed, mesic Typic Argiudolls 82 11 109 Racoon Fine-silty, mixed, mesic Typic Ochraqualfs 34 36 430 Raddle Fine-silty, mixed, mesic Typic Hapludolls 92 11 74 Radford Fine-silty, mixed, mesic Fluvaquentic Hapludolls 283 24 238 Rantoul Fine, montmorillonitic, mesic Vertic Haplaquolls 122 16, 17 481 Raub Fine-silty, mixed, mesic Aquic Argiudolls 97 12 594 Reddick Fine-loamy, mixed, mesic Typic Haplaquolls 116, 127 15, 16, 17 723 Reesville Fine-silty, mixed, mesic Aerie Ochraqualfs 14, 133 31, 32, 33, 46 4 Richview Fine-silty, mixed, mesic Mollic Hapludalfs 29 6 151 Ridgeville Coarse-loamy, mixed, mesic Aquic Argiudolls 191 22 743 Ridott Fine-silty, mixed, mesic Mollic Ochraqualfs 253 56 452 Riley Fine-loamy over sandy or sandy-skeletal, mixed, mesic Fluva¬ quentic Hapludolls 263 24 297 Ringwood Fine-loamy, mixed, mesic Typic Argiudolls 110 13 324 Ripon Fine-silty, mixed, mesic Typic Argiudolls 210 23 Soils of Illinois 81 Alphabetical List of Illinois Soils (continued) Soil Line in associa- No. Series Family Soil Key tion area 311 Ritchey Loamy, mixed, mesic Lithic Hapludalfs 200 51 335 Robbs Fine-silty, mixed, mesic Aquic Fragiudalfs 248 55 184 Roby Coarse-loamy, mixed, mesic Aquic Hapludalfs 193 50 503 Rockton Fine-loamy, mixed, mesic Typic Argiudolls 217 23 93 Rodman Sandy-skeletal, mixed, mesic Typic Hapludolls 146 20 316 Romeo Loamy, mixed, mesic Lithic Haplaquolls 198 23 73 Ross Fine-loamy, mixed, mesic Cumulic Hapludolls 266 24 230 Rowe Fine, mixed, mesic Typic Argiaquolls 124 17 279 Rozetta Fine-silty, mixed, mesic Typic Hapludalfs 13 32 178 Ruark Fine-loamy, mixed, mesic Typic Ochraqualfs 193 50 791 Rush Fine-silty, mixed, mesic Typic Hapludalfs 90 41 16 Rushville Fine, montmorillonitic, mesic Typic Albaqualfs 22, 26 34 322 Russell Fine-silty, mixed, mesic Typic Hapludalfs 99 42 375 Rutland Fine, montmorillonitic, mesic Aquic Argiudolls 70 10 236 Sabina Fine, montmorillonitic, mesic Aerie Ochraqualfs 69 39 68 Sable Fine-silty, mixed, mesic Typic Haplaquolls 8, 18 2, 3 956 Saffell Loamy-skeletal, siliceous, thermic Typic Hapludults 247 54 92 Sarpy Mixed, mesic Typic Udipsamments 257 57 774 Saude Coarse-loamy over sandy or sandy-skeletal, mixed, mesic Hapludolls Typic 151 20 107 Sawmill Fine-silty, mixed, mesic Cumulic Haplaquolls 285 24 145 Saybrook Fine-silty, mixed, mesic Typic Argiudolls 94 12 370 Saylesville Fine, illitic, mesic Typic Hapludalfs 135 46 418 Schapville Fine, mixed, mesic Typic Argiudolls 250 56 462 Sciotoville Fine-loamy, mixed, mesic Aquic Fragiudalfs 177 49 274 Seaton Fine-silty, mixed, mesic Typic Hapludalfs 4 31 563 Seaton, sandy sub. Fine-silty, mixed, mesic Typic Hapludalfs 5 31 125 Selma Fine-loamy, mixed, mesic Typic Haplaquolls 172 21 508 Selma, br. sub. Fine-loamy, mixed, mesic Typic Haplaquolls 221 23 208 Sexton Fine, montmorillonitic, mesic Typic Ochraqualfs 84 41 555 Shadeland Fine-loamy, mixed, mesic Aerie Ochraqualfs 236 56 72 Sharon Coarse-silty, mixed, acid, mesic Typic Udifluvents 272 57 138 Shiloh Fine, montmorillonitic, mesic Cumulic Haplaquolls 297 24 424 Shoals Fine-loamy, mixed, nonacid, mesic Aerie Fluvaquents 264 57 745 Shullsburg Fine, mixed, mesic Aquic Argiudolls 250 56 55 Sidell Fine-silty, mixed, mesic Typic Argiudolls 97 12 504 Sogn Loamy, mixed, mesic Lithic Haplustolls 201 23 88 Sparta Sandy, mixed, mesic Entic Hapludolls 180 22 243 St. Charles Fine-silty, mixed, mesic Typic Hapludalfs 74 41 560 St. Clair Fine, illitic, mesic Typic Hapludalfs 120, 126 45 132 Starks Fine-silty, mixed, mesic Aerie Ochraqualfs 84 41 155 Stockland Loamy-skeletal, mixed, mesic Typic Hapludolls 147 20 665 Stonelick Coarse-loamy, mixed (calcareous), mesic Typic Udifluvents 260 57 253 Stonington Coarse-loamy, mixed, mesic Typic Hapludalfs 148 48 164 Stoy Fine-silty, mixed, mesic Aquic Hapludalfs 28, 244 35, 54 224 Strawn Fine-loamy, mixed, mesic Typic Hapludalfs 104 42, 43 435 Streator Fine, montmorillonitic, mesic Typic Haplaquolls 70 10 278 Stronghurst Fine-silty, mixed, mesic Aerie Ochraqualfs 13 32 234 Sunbury Fine, montmorillonitic, mesic Aquollic Hapludalfs 68 39 91 Swygert Fine, mixed, mesic Aquic Argiudolls 118 16 19 Sylvan Fine-silty, mixed, mesic Typic Hapludalfs 14 31, 32, 33 294 Symerton Fine-loamy, mixed, mesic Typic Argiudolls 116 15 34 Tallula Coarse-silty, mixed, mesic Typic Hapludolls 6 1, 2, 3 36 Tama Fine-silty, mixed, mesic Typic Argiudolls 8, 18, 23 2, 3, 4 581 Tamalco Fine, montmorillonitic, mesic Typic Natrudalfs 36 4, 5, 6 565 Tell Fine-silty over sandy or sandy-skeletal, mixed, mesic Hapludalfs Typic 64 20 587 Terril Fine-loamy, mixed, mesic Cumulic Hapludolls 268 24 212 Thebes Fine-silty over sandy or sandy-skeletal, mixed, mesic Hapludalfs Typic 66 38 82 Bulletin 778 Alphabetical List of Illinois Soils (continued) No. Series Family Line in Soil Key Soil associa¬ tion area 206 Thorp Fine-silty, mixed, mesic Argiaquic Argialbolls 79 11 284 Tice Fine-silty, mixed, mesic Fluvaquentic Hapludolls 284 24 271 Timula Coarse-silty, mixed, mesic Typic Eutrochrepts 7 31 404 Titus Fine, montmorillonitic, mesic Fluvaquentic Haplaquolls 296 24 353 Toronto Fine-silty, mixed, mesic (Mollic) Udollic Ochraqualfs 98 42 633 Traer Fine, montmorillonitic, mesic Typic Ochraqualfs 13 32 765 Trempealeau Fine-loamy over sandy or sandy-skeletal, mixed mesic Argiudolls Typic 169 21 197 Troxel Fine-silty, mixed, mesic Typic Argiudolls 78 11 482 Uniontown Fine-silty, mixed, mesic Typic Hapludalfs 133 46 605 Ursa Fine, montmorillonitic, mesic Typic Hapludalfs 41 32, 33, 34, 35, 36 223 Varna Fine, illitic, mesic Typic Argiudolls 112 14 250 Velma Fine-loamy, mixed, mesic Typic Argiudolls 38 3, 4, 5, 6 50 Virden Fine, montmorillonitic, mesic Typic Argiaquolls 23 4 104 Virgil Fine-silty, mixed, mesic Udollic Ochraqualfs 73 41 83 Wabash Fine, montmorillonitic, mesic Vertic Haplaquolls 299 24 26 Wagner Fine, montmorillonitic, mesic Mollic Albaqualfs 142 46 333 Wakeland Coarse-silty, mixed, nonacid, mesic Aerie Fluvaquents 271 57 292 Wallkill Fine-loamy, mixed, nonacid, mesic Thapto-Histic Fluvaquents 269 57 584 Walshville Fine, mixed, mesic Typic Natrudalfs 37 4, 5, 6 456 Ware Coarse-loamy, mixed, thermic Fluventic Hapludolls 262 24 290 Warsaw Fine-loamy over sandy or sandy-skeletal, mixed, mesic Argiudolls Typic 156 20 215 Wartrace Fine-silty, mixed, mesic Typic Hapludalfs 28, 244 35, 54 296 Washtenaw Fine-loamy, mixed, nonacid, mesic Typic Haplaquents 275 57 49 Watseka Sandy, mixed, mesic Aquic Hapludolls 180 22 697 Wauconda Fine-silty, mixed, mesic Udollic Ochraqualfs 86 41 727 Waukee Fine-loamy over sandy or sandy-skeletal, mixed, mesic Hapludolls Typic 162 20 564 Waukegan Fine-silty over sandy or sandy-skeletal, mixed, mesic Hapludolls Typic 63 8 369 Waupecan Fine-silty, mixed, mesic Typic Argiudolls 88 11 398 Wea Fine-loamy, mixed, mesic Typic Argiudolls 166 20 461 Weinbach Fine-silty, mixed, mesic Aerie Fragiaqualfs 177 49 165 Weir Fine, montmorillonitic, mesic Typic Ochraqualfs 28, 244 35, 54 339 Wellston Fine-silty, mixed, mesic Ultic Hapludalfs 240 53, 54, 55 388 W'enona Fine, montmorillonitic, mesic Typic Argiudolls 70 10 141 Wesley Coarse-loamy, mixed, mesic Aquic Hapludolls 117 14, 15, 19 300 Westland Fine-loamy, mixed, mesic Typic Argiaquolls 153, 166 20 940 Westmore Fine-silty, mixed, mesic Typic Hapludalfs 242 53, 54 22 Westville Fine-loamy, mixed, mesic Typic Hapludalfs 53 37 509 Whalan Fine-loamy, mixed, mesic Typic Hapludalfs 218 51 463 Wheeling Fine-loamy, mixed, mesic Ultic Hapludalfs 177 49 571 Whitaker Fine-loamy, mixed, mesic Aerie Ochraqualfs 173 49 116 Whitson Fine-silty, mixed, mesic Typic Ochraqualfs 14 31, 32, 33 329 Will Fine-loamy over sandy or sandy-skeletal, mixed, mesic Haplaquolls Typic 156 20 348 Wingate Fine-silty, mixed, mesic Mollic Hapludalfs 98 42 728 Winnebago Fine-loamy, mixed, mesic Typic Argiudolls 52 7 410 Woodbine Fine-loamy, mixed, mesic Typic Hapludalfs 207 51 37 Worthen Fine-silty, mixed, mesic Cumulic Hapludolls 91 11 12 Wynoose Fine, montmorillonitic, mesic Typic Albaqualfs 33 36 291 Xenia Fine-silty, mixed, mesic Aquic Hapludalfs 99 42 340 Zanesville Fine-silty, mixed, mesic Typic Fragiudalfs 241 53, 54, 55 524 Zipp Fine, mixed, nonacid, mesic Typic Haplaquepts 137 46 696 Zurich Fine-silty, mixed, mesic Typic Hapludalfs 87 41 576 Zwingle Fine, montmorillonitic, mesic Typic Albaqualfs 141 46 Soils of Illinois 83 Numerical List of Illinois Soils and Soil Association Areas Soil no. series and name Soil associa¬ tion area Soil series no. and name Soil associa¬ tion area Soil series no. and name Soil associa¬ tion area 2 Cisne . . ..6 78 Arenzville . . ...57 173 McGary .. . .. .46 3 Hoyleton .. . . .6 81 Littleton . .. . .. 11 175 Lament .. . .. .50 4 Richview .. . . .6 176 Marissa ... . ..46 5 Blair . . . .31,32,33,34,35,36 82 Millington . ...24 178 Ruark. ...50 6 Fishhook .. ...32,34 83 Wabash . .. ...24 180 Dupo . .. .57 7 Atlas. . . .32,33,34,35,36 84 Okaw . . . .46 8 Hickory . .. . . .31,32,33,34,35,36 85 Jacob . . . .57 184 Roby. .. .50 12 Wynoose . . . . .36 87 Dickinson . . ...22 187 Milroy .... .. .21 13 Bluford .... . . .36 88 Sparta. ...22 188 Beardstown .. .21 14 Ava. . . .36 89 Maumee . .. . . .22 189 Martinton . .. .19 91 Swygert . .. .. .16 191 Knight .... .. .11 15 Parke . .. .33,34,35,36 92 Sarpy . . . .57 192 Del Rey . .. .. .46 16 Rushville . . .. .34 93 Rodman . .. ...20 194 Morley .... . . .44 17 Keomah ... . . .34 196 Lemond ... . ..11 18 Clinton .... . ..34 97 Houghton . . .. .25 197 Troxel . .. . .. .11 19 Sylvan. . . .31,32,33 98 Ade. . . .22 198 Elburn .... .. .11 21 Pecatonica . .. .37 100 Palms . . . .25 22 Westville . . ...37 102 La Hogue . . .. .21 199 Plano . ...11 23 Blount. .. .44 103 Houghton . . . . .25 200 Orio . .. .21 24 Dodge . . . .42 104 Virgil . . . .41 201 Gilford . ... ...22 25 Hennepin . . . . .39,42,43 105 Batavia . ... . . .41 204 Ayr . .. .12,13 107 Sawmill . .. .. .24 205 Metea. . . .42,43 26 Wagner . . . . . .46 108 Bonnie . ... .. .57 206 Thorp. ...11 27 Miami .... .. .42 109 Racoon . . . . ...36 208 Sexton .... .. .41 28 Jules . .. .57 210 Lena . ...25 29 Dubuque .. .. .51 112 Cowden . .. . . .5 212 Thebes .... .. .38 30 Hamburg .. .. .31,32,33 113 Oconee . . .. .. .5 214 Hosmer . .. . ..35,54 34 Tallula .... ...1,2,3 116 Whitson . .. . . .31,32,33 35 Bold . .. .31,32,33 119 Elco . . . .32,33,34 218 Newberry . . .. .6 36 Tama . ...2,3,4 120 Huey. ...4,5,6 219 Millbrook . . .. .11 37 Worthen . .. . . .11 122 Colp . . . .46 221 Parr . ...12 40 Dodgeville . .. .23 125 Selma . .. .21 223 Varna. .. .14 127 Harrison . .. .. .4,5 224 Strawn . .. . ...42,43 41 Muscatine . . . .2 128 Douglas . .. ...4,5 227 Argyle. .. .37 42 Papineau . . 131 Alvin . . . .50 228 Nappanee . . .. .45 43 Ipava . . . .3 229 Monee .... .. .16,17 45 Denny .... ...2,3 132 Starks . . . .41 230 Rowe . . . .17 46 Herrick .... . . .4 134 Camden . . . . . .41 232 Ashkum . .. .. .14 48 Ebbert .... .. .6 136 Brooklyn . . .. . 11 49 Watseka .. . . . .22 137 Ellison . . .. .. .48 233 Birkbeck . .. ...39 50 Virden .... .. .4 138 Shiloh. .. .24 234 Sunbury . .. . ..39 53 Bloomfield . .. .50 141 Wesley . ... .. .14,15,19 235 Bryce . .. .16 54 Plainfield . . ...50 142 Patton. ...18 236 Sabina . ... .. .39 145 Saybrook . . .. .12 238 Rantoul ... ...16,17 55 oidell . 146 Elliott. .. .14 239 Dorchester . .. .57 56 Dana . ... 12 147 Clarence . .. ...17 240 Plattville .. . . .23 57 Montmorenci . ..42 241 Chatsworth . . .44,45 59 Lisbon .... . . .12 148 Proctor . ... . . .11 242 Kendall . .. .. .41 60 La Rose . .. ....12,13 149 Brenton . .. . . .11 243 St. Charles . .. .41 61 Atterberry . .. .32 150 Onarga . ... ...22 62 Herbert . .. ....42 151 Ridgeville . .. .22 244 Hartsburg . . . . .3 67 Harpster . .. .. .2,3,9,11 152 Drummer . . . .9,11,12 248 McFain .. . .. .24 68 Sable. ....2,3 153 Pella . . ..9,11,12 249 Edinburg . . .. .3 69 Milford .... .. ..19 154 Flanagan . .. .9 250 Velma .. .. ...3,4,5,6 155 Stockland .. .. .20 253 Stonington . . . .48 70 Beaucoup .. .... 24 159 Pillot . . . .8 256 Pana . ...4,5,6 71 Darwin .... .... 24 162 Gorham . . ...24 257 Clarksdale . .. .34 72 Sharon .... ....57 259 Assumption .. . 2,3,4 73 Ross . ....24 164 Stoy . .. .35,54 261 Niota . .. .46 74 Radford . .. ....24 165 Weir. . ..35,54 262 Denrock . .. .. .19 75 Drury . ....41 167 Lukin . .. .6 76 Otter. ....24 171 Catlin. . ..9 264 El Dara . .. . . .34 77 Huntsville . ....24 172 Hoopeston . . .22 265 Lomax . .. . .. .22 84 Bulletin 778 Numerical List of Illinois Soils and Soil Association Areas (continued) Soil series no. and name Soil associa¬ tion area Soil series no. and name Soil associa¬ tion area Soil no. series and name Soil associa¬ tion area 266 Disco . . ..22 340 Zanesville . . .. .53,54,55 451 Lawson. .24 268 Mt. Carroll . . .31 342 Matherton . .. .48 452 Riley. .24 271 Timula . . . .. .31 343 Kane. . . .20 453 Muren . .33,52,53 272 Edgington . ...1,2 344 Harvard . . . . . .41 454 Iva . .33,52,53 274 Seaton . . . . . . .31 346 Dowagiac . . .. .48 275 Joy . . . .1 347 Canisteo . .. . .. 11 456 Ware . .24 277 Port Byron . . . .1 348 Wingate ... ...42 457 Booker . . 19,24 278 Stronghurst . . .32 353 Toronto . . . . . .42 4b0 Ginat . .49 354 Hononegah . ..20 461 Weinbach .... .49 279 Rozetta .... .. .32 361 Kidder .... .. .43 462 Sciotoville . . . .49 280 Fayette . .. . . . .32 463 Wheeling .... .49 282 Chute . .. .50 363 Griswold . . .. .13 465 Montgomery . .18,19 284 Tice . . . .24 365 Aptakisic . . . . .41 467 Markland .... .46 286 Carmi. . . .20 369 Waupecan . .. .11 469 Emma . .49 287 Chauncey . . . . .6 370 Saylesville . .. .46 470 Keller. .2,3,4 288 Petrolia . .. .. .57 375 Rutland . . . . ..10 289 Omaha .... . . .20 379 Dakota .... . . .20 471 Clarksville 290 Warsaw . . . . . .20 380 Fieldon .... . .20 (or Bodine) .52 291 Xenia . .. .42 382 Belknap . .. . .57 472 Baylis . .52 386 Downs .... . . .32,34 474 Piasa . .4,5,6 292 Wallkill . .. . . .57 387 Ockley .... . . .48 475 Elsah . .57 293 Andres . . . . .. .15 481 Raub. .12 294 Symerton . . .. .15 388 Wenona ... .. .10 482 Uniontown . . . .46 295 Mokena . . . ...16,17 389 Hesch, thin 484 Harco. .18 296 Washtenaw . . .57 to ss .... . .56 490 Odell . .12 297 Ringwood .. .13 390 Hesch . . .56 493 Bonfield . .23 298 Beecher .. . . . .44 393 Marseilles, 494 Kankakee .... .23 300 Westland . . ...20 gray subs. . .56 301 Grantsburg . . . .55 397 Boone . . .56 495 Corwin. .12 302 Ambraw . . . . . .24 398 Wea . . . .20 496 I incastle. .42 400 Calco . . . .24 501 Morocco. .50 304 Landes .... .. .24 402 Colo . . . .24 503 Rockton. .23 306 Allison .... . . .24 404 Titus. .. .24 504 Sogn . .23 307 Iona . .. .31,32,33 410 Woodbine . . .51 505 Dunbarton . . . .51 308 Alford. . . .33,52,53 506 Hitt. .23 310 McHenry . . .. .43 411 Ashdale .. . . .23 508 Selma, br. sub. .23 311 Ritchey . . . . . .51 412 Ogle . . .7 509 Whalan . .51 312 Edwards . . . . . .25 413 Gale . . .56 511 Ehmbarton, chr. 51 314 Joliet . .. .23 414 Myrtle .... . .37 315 Channahon .. .23 415 Orion . . .57 513 Granby. .22 316 Romeo .... .. .23 416 Durand .... . .7 516 Faxon . .23 417 Derinda .. . . .56 524 Zipp . .46 317 Millsdale .. . . .23 418 Schapville . . .56 531 Markham .... .44 318 Lorenzo .. . .. .20 419 Flaear . . .37 537 Hesch, 320 Frankfort . . .. .45 420 Piopolis . .. ..57 gray subs. . . .56 321 Uu Page . . . . . .24 546 Keltner. .56 322 Russell .... .. .42 421 Kell . .. .36 547 Eleroy. .56 323 Casco . .. .48 422 Cape. . .57 549 Marseilles .... .56 324 Ripon . .. .23 424 Shoals .... . .57 551 Gosport . .56 325 Dresden . .. .. .48 425 Muskingum . .53,54,55 554 Keman. .45 326 Homer .... .. .48 426 Karnak .... . .57 327 Fox . .. .48 427 Burnside . . . . .57 555 Shadeland . . . .56 428 Coffeen .... . .11 556 High Gap .... .56 329 Will . .. .20 429 Palsgrove . . . .51 560 St. Clair. 45 330 Peotone .. . .. .9,14 430 Raddle .... . .11 562 Port Byron, 331 Haymond . . .. .57 431 Genesee .. . . .57 san. sub. . .. .1 332 Billett. . . .50 563 Seaton, 333 Wakeland . .. .57 435 Streator . . . . .10 san. sub. . .. 31 334 Birds. .. .57 440 Jasper . . .21 564 Waukegan .. . .8 335 Robbs. .. .55 442 Mundelein . .. .11 565 Tell. .38 337 Creal . .. .36 443 Barrington . . .11 567 Elkhart. 3 338 Hurst . . . .46 444 Bungay .... . .46,57 568 Niota, thin A . 46 339 Wellston ... .. .53,54,55 448 Mona . . .16,17 570 Martinsville .. 49 Soils of Illinois 85 Numerical List of Illinois Soils and Soil Association Areas (continued) Soil series no. and name Soil associa¬ tion area 571 Whitaker . ... . .49 572 Loran . , .56 574 Ogle, sil. sub. , , .7 576 Zwingle . . .46 578 Dorchester, cobbly. ,.57 581 Tamalco. ..4,5,6 583 Pike . , .33,34,35 584 Walshville . . . , .4,5,6 585 Negley . ..33,34,35,36 587 Tcrril . , .24 589 Bowdre. , .24 590 Cairo . .24 591 Fults. , .24 592 Nameoki . ... .24 594 Reddick . , .15,16,17 597 Armiesburg . , , .24 598 Bedford . , .52 599 Baxter. .52 600 Huntington . . ,.24 603 Blackoar . .24 605 Ursa . , .32,33,34,35,36 606 Goss . .52 609 Crane . ,.20 619 Parkville. .24 620 Darmstadt . . . .4,5,6 628 Lax. .54 633 Traer . , .32 638 Muskego. .25 Soil series tion area Soil series Soil associa no. and name ■Soil associa- no. and name tion area 647 Lawler . .20 746 Calamine ... .56 649 Nachusa .... .11 752 Oneco. .51 650 Prairieville . . 753 Massbach . .. .56 .11 761 Eleva . .56 656 Octagon .... .42 763 Joslin . ..11,19 660 Coatsburg . . .4,5,6 661 Atkinson .... .23 764 Coyne. . .11,19 665 Stonelick . .. .57 765 Trempealeau .21 670 Aholt . .19 768 Backbone . .. .51 673 Onarga, red 769 Edmund .... .23 subs. .22 771 Hayfield .... .48 682 Medway .... .24 772 Marshan .... .20 683 Lawndale . .. .8 774 Saude . .20 684 Broadwell .. . .8 776 Comfrey .... .24 685 Middletown . .38 777 779 Adrian . Chelsea. .25 .50 691 Beasley. .54,55 696 Zurich . .41 780 Grellton .... .49 697 Wauconda . . .41 781 Friesland . .. .21 698 Grays . .41 782 Juneau . .57 706 Boyer . .48 783 Flagler . .20 723 Reesville . .. .31,32,33,46 786 Frondorf .... .35,36 727 Waukee .... .20 787 Banlic. .57 728 Winnebago . . .7 791 Rush. .41 731 Nasset. .51 792 Bowes. .41 740 741 Darroch .... Oakville .... 928 New Glams- .21 .50 956 Palsgrove . . .51 Brandon-Saffell 54 742 Dickinson, loamy sub. .22 961 Burkhardt- 743 Ridott. .56 Saude .... ..20 745 Shullsburg . . .56 977 Neotoma . .. .53,54,55 V 268 442 453 41 621 425 414 Mt. Carroll Mundelein Muren Muscatine Muskego Muskingum Myrtle Fine-silty, mixed, mesic Mollic Hapludalfs Fine-silty, mixed, mesic Aquic Argiudolls Fine-silty, mixed, mesic Aquic Hapludalfs Fine-silty, mixed, mesic Aquic Hapludolls (Most Muscatine in Illinois is in Aquic Argiudolls.) Coprogenous, euic, mesic Limnic Medisaprists Fine-loamy, mixed, mesic Typic Dystrochrepts Fine-silty, mixed, mesic Mollic Hapludalfs 3 85 17, 228, 243 8 308 235 59 649 Nachusa Fine-loamy, mixed, mesic Aquic Argiudolls 42 592 Nameoki Fine, montmorillonitic, mesic Fluvaquentic Hapludolls 289 228 Nappanee Fine, illitic, mesic Aerie Ochraqualfs 120, 126 731 Nasset Fine-silty, mixed, mesic Mollic Hapludalfs 213 585 Negley Fine-loamy, mixed, mesic Typic Paleudalfs 48 976,977 Neotoma Loamy-skeletal, mixed, mesic Ultic Hapludalfs 231 218 Newberry Fine-silty, mixed, mesic Mollic Ochraqualfs 32 928 New Glarus Fine-silty over clayey, mixed, mesic Typic Hapludalfs 209 261 Niota Fine, mixed, mesic Mollic Albaqualfs 139 568 Niota, thin A Fine, mixed, mesic Mollic Albaqualfs 140 741 Oakville Mixed, mesic Typic Udipsamments 183 387 Ockley Fine-loamy, mixed, mesic Typic Hapludalfs 168 113 Oconee Fine, montmorillonitic, mesic Udollic Ochraqualfs 27 656 Octagon Fine-loamy, mixed, mesic Mollic Hapludalfs 101 490 Odell Fine-loamy, mixed, mesic Aquic Argiudolls 100 412 Ogle Fine-silty, mixed, mesic Typic Argiudolls 57 574 Ogle, silt loam Fine-silty, mixed, mesic Typic Argiudolls 58 substratum 84 Okaw Fine, montmorillonitic, mesic Typic Albaqualfs 143 289 Omaha Coarse-loamy, mixed, mesic Aquic Hapludolls 153 150 Onarga Coarse-loamy, mixed, mesic Typic Argiudolls 191 673 Onarga, red subsoil Coarse-loamy, mixed, mesic Typic Argiudolls 192 752 Oneco Fine-loamy, mixed, mesic Mollic Hapludalfs 206 200 Orio Fine-loamy, mixed, mesic Mollic Ochraqualfs 174 415 Orion Coarse-silty, mixed, nonacid, mesic Aquic Udifluvents 274 76 Otter Fine-silty, mixed, mesic Cumulic Haplaquolls 282 100 Palms Loamy, mixed, euic, mesic Terric Medisaprists 306 429 Palsgrove Fine-silty, mixed, mesic Typic Hapludalfs 214 256 Pana Fine-loamy, mixed, mesic Typic Argiudolls 47 42 Papineau Fine-loamy over clayey, mixed, mesic Aquic Argiudolls 128 15 Parke Fine-silty, mixed, mesic Ultic Hapludalfs 49 619 Parkville Clayey over loamy, montmorillonitic, mesic Fluvaquentic Hapludolls 291 221 Parr Fine-loamy, mixed, mesic Typic Argiudolls 100 142 Patton Fine-silty, mixed, mesic Typic Haplaquolls 131 21 Pecatonica Fine-loamy, mixed, mesic Typic Hapludalfs 56 153 Pella Fine-silty, mixed, mesic Typic Haplaquolls 85, 100 330 Peotone Fine, montmorillonitic, mesic Cumulic Haplaquolls 115 288 Petrolia Fine-silty, mixed, nonacid, mesic Typic Fluvaquents 277 474 Piasa Fine, montmorillonitic, mesic Mollic Natraqualfs 35 583 Pike Fine-silty, mixed, mesic Ultic Hapludalfs 51 159 Pillot Fine-silty over sandy or sandy-skeletal, mixed, mesic Typic Argiudolls 65 GENERAL SOIL MAP OF ILLINOIS Prepared by J.B. Fehrenbacher, Professor of Pedology; J.D. Alex¬ ander and I.J. Jansen, Associate Professors of Pedology; R.A. Pope, Assistant Professor of Soil Management; M.A. Flock, Assistant Agronomist; all of the Department of Agronomy, University of Illinois at Urbana-Champaign; and W.F. Andrews, L.J. Bushue, J.W. Scott, and E.E. Voss, Soil Scientists, Soil Conservation Ser¬ vice, U.S. Department of Agriculture. The authors are indebted to the other soil scientists involved in the Soil Survey of Illinois for their help in the many studies that have led to the publication of this map. This map accompanies the Illinois Agricultural Experiment Station bulletin Soils of Illinois. The Illinois Agricultural Experiment Station provides equal opportunities in programs and employment. Agricultural Experiment Station, College of Agriculture University of Illinois at Urbana-Champaign In cooperation with the Soil Conservation Service, U.S. Department of Agriculture t ■n . '( -A. I UNtVERSmr OF ILLINOS-URBANA 3 011211 3300617 ' In ’ ^.'‘ - ■fj', 'jrl- • . I:- •; • . .ar. . . . -..A’ P 1 ■ i- ■'