III ill "LI B R.AFLY OF THE UNIVERSITY OF ILLINOIS I-PGb cap. 2. A6RICULTUME NOTICE: Return or renew all Library Materials! The Minimum Fee for each Lost Book is $50.00. The person charging this material is responsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for discipli- nary action and may result in dismissal from the University. To renew call Telephone Center, 333-8400 UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN APR 11996' L161 O-1096 tyftT. Bulletin 522 University of Illinois griculturai Experiment Station CONTENTS PAGE Long-Time Farm Records Studied 373 Characteristics and Location of Soil Types 379 How Management Practices Alter Crop Yields 379 A Yardstick for Central Illinois Farmers 384 Achieving Efficient Production on Your Farm 387 Summary 389 Urbana, Illinois March, 1947 Publications in the Bulletin series report the results of investigations made or sponsored by the Experiment Station HOW PRODUCTIVE ARE THE SOILS OF CENTRAL ILLINOIS? By RUSSELL T. ODELL' Assistant Chief, Soil Physics and Soil Survey HOW do crop yields on my farm compare with those on other farms having the same soil type ? What crop yields are obtained under good soil management on farms hav- ing soils similar to those on my farm ? What can I do to get better yields? These are examples of questions that farmers thruout Illi- nois have been asking. Other inquiries come to this Station from people wanting to buy land. A man writes: "I am planning to buy a tract of land and have been offered one on Tama silt loam and one on Drummer clay loam. What crop yields can I expect on these two soil types under fair management and also under good management?" Prospective buyers of land in central and northeastern Illinois often want to know how much the impervious glacial till underlying Clarence silt loam and Rowe clay loam to clay limits crop yields. These and many similar questions can be answered only by figures showing what crop yields are being obtained on various kinds of soil when managed in different ways. This publication presents a summary of yields which farmers have obtained during the twenty years from 1925 thru 1944 on some important soil types in central Illinois. Crop yields obtained on four of the University's soil experiment fields are also included for comparison. Long-Time Farm Records Studied Since 1938 the Agronomy Department of the University of Illinois has been mapping the soils and collecting records of crop yields and soil-treatment practices on central Illinois farms. Most of the records go back ten to twenty years. 1 The work reported in this bulletin was initiated by R. S. SMITH, Chief in Soil Physics and Soil Survey. GUY D. SMITH, formerly Associate in Soil Physics and Soil Survey, did the first year's work on the problem in 1938, and the author has continued the study since that time. 373 374 BULLETIN No. 522 [March, Some of the records which form the basis for this study have been kept by farmers in cooperation with the Department of Agri- cultural Economics of the University of Illinois; some have been kept by fieldmen and farm managers for life-insurance companies and large private estates ; and some have been kept by farmers for their own use. 1 Altogether the records from 551 farms scattered over 41 coun- ties have been examined. Some of these farms were omitted from the final study because their records were incomplete. Others were dropped because the soils in the different fields were too variable. To be included in this study, a field had to fit into one of three classifications. If as much as 90 percent of the area was of a single soil type and the rest was a closely related type of similar produc- tivity, the field was considered a single type. If a field was made up of 40 to 60 percent of each of two associated types or of 25 to 40 percent of each of three associated types, it was listed as being composed of associated types. Fields which included two or more soil types that did not occur in the proportions indicated were omitted from this study. From the 551 farms, records for 444 tracts have been brought together in Table 1. "Tract" is used here to indicate an area made up of one or more fields on a single farm sometimes the entire farm. All the fields in a tract had to be uniform enough in soil type to fit into one of the classifications described in the preceding para- graph. Management practices, such as soil treatment and cropping systems, also had to be similar on all fields that were included in a single tract. The tracts are grouped in Table 1 according to both soil type and soil management. These are the two important factors influ- encing crop yields, aside from climate and the adaptation of a crop to the conditions under which it is produced. The number of tracts in each soil-type and soil-management group gives some idea of the reliability of the averages. 'Acknowledgment is due to the Department of Agricultural Economics of the University of Illinois and to the farmers and others who have kept the records used in this study for their generous cooperation. 1947] PRODUCTIVITY OF CENTRAL ILLINOIS SOILS 1 ij-g ||| fiSR-SRSS S ^-$2 2S if ll S^OMOl^vOP-ll^^. ir> i/) DON r> 00>OfS < g'S J " '5 .S a - - o? .1 ; M & |IJ| 5|| tfRSgxs;* s aa < 8 = 2 a .js S ^ 3 '" o e i 4) s o ia ^ 0- ^^3 ,^ C fO 1 c 1.1 o 62 t* H tft &o fisasaaaas s aassa s aaa "S 3 Be = 8 2 j? g ** -H(S-H c S > X! V) e o 1 i o ^^?;^^^ 3 5^?%5 5 5?^^ .2 u , ^ o < 1 rt , *rt t? cs ^ g rt > .ous cr< a ^^*O^ -OO^^O >O t-O-r-.i/) f*5 OO^Os ^fS(N(N -fNCSCN (N fSfS-fsJC 1 ^ fS fs|fs)v-( S o 2 M Wjj o, C- J 1 ssless Rg822 55S5SB53 S 3W5S 5 3fiS | " r^" 1 o Kio 2 i'SgSRSSS S !CS:^S; S SSS O 5 *-,_ *^ 5^ z ii -2S-2- n *s~~ i - C i 01 ecu fi '^"O'O'O'D "O "Ct-'O *UL_ O T; rt c O.ts O.t; O.ho 0-- .fc O.t! o w|a| Ofe o o o ou! o (3(2(2 (3t2 i2 ot2i o tn 2 ^^ U-g.^,,, rt^ rt^ ...^ .2 4) s- ^ s.| |^J *| as aS as t>I ^ 13 jj^ ^ !> JJ^o* "el "" "=5 V bo fe rt OT ^ ~ ^> S E 'T) 3 >. E'O E'O E'3 a o. ? O >>T3 - _o-ooo |^ -c .2| j| || V r 1 1 i 1 i-if If 1 is 1^ IL l! s footnotes c u Q 2 $"" .a.o.o.n.0 * jj co - o PH tZ . 5 JS S 2 -" 376 BULLETIN No. 522 \March, C o U W OH H J I I o c/3 H to 1 to 1 to to Q - 2 - O 03 Q 1-1 W - U I S 3 fi a uct TS M^o o a - ,8-8 2 C 4> S en a 3 to CStS-H CS-H rtH o o (S {SIM O r5 O t'O "t~H t> < t) fs5<*5 ^ ^H -^ ts rt t^ rt 10 3 S .S Og2 S^ H N roHts (NCS ^cscscscs^o (Ntscs cs csts (SCS H m M g 2 -? S fcS L 555? S ^ cs cs c^ ,* cs c< r 10 ^H r- oo ^-< O 22 S>5 '^ *t^?N *^O^ f*5 **5 O'O'^'^^O -*o^^ *^ ^O OO* | 22 5N " mill *" 'Ef*^^ -^ '^ - "j*Aiv*j S^ -2 * "^ ^^ l! 1! J>j cu w o rt c " % "o to" J3 t>- IO CS o t CS \O ^H *O ro CS IO J3 C "u-S c o'tj S" * *!* o ^, g 60 'S " * ro O O 3 _c rt vP Tjt- o 00 vO ro- cs>o O "o SiS cs cs ||H g o o u ^2 ^3 cu {5? CSCS VI ^* *o es cs ro ^< cso _rj S 60 ^ C J3 ? CO ^ cd ^ e 3 ** 3 O> *" V 11 2 gy. 00-0 00 100 00 r- ro vo 0000 at- J^ rt rt V V * -a S u & IM rt cS^ o-- E S -2 . *O fc- ^H * CSCS 10 c f)t- Ooo *a OviO rtpc' '.n sO CSOO o 00 fO CS CSIO ^ IO t IO o c *"* 2 y *I* L fl^ o *> J3 1) 11 P cd S3 S .J3 J3 8 -^ C " c .; cscs cs ro IO O NO *"" O ^* w , rj eti cd *o -- cd .5 cscs cs cs cs CS cscs __ *"* 3 Q ^1 m ^fi 1 - o o .c 2 H 5 !*5" 5 10-* S5 OOO 5 csoo 1*111 ^ |^ S|-a cu O (d o ci 'O'S'3 - _ !3 5 d "3 .2 c -4J W O cu 10 cs 5 cscs cs cscs CSCS cs cscs ^ CJ U C O oj ^* > S; ^ Cd *O R HrfS E ri^ |.s |1 J !?S5 a 10 * 3 S3 5 35 ^Dl| I-, "> !H xo c r3 c cd S, E . S*^ > ** j3 >5 3 * T3 (*/) t vo *o IO ^ PO t t t *iO O f*i ^ i- H Q."* ^ rt 10 * J-i *3 U cd ts W~ 2fc"S S (S C o a ^ g tn .. u 8 fc *j "" ** o *-j 2 S c CO J2 ^*^i- ( .a S c o u t, "O *T3 o ^ o ^ "O "t3 ^ tu ^ o _ cd ^ c . > >. 5 -o J'cd 8 fcCu II O'cd J'rt fe J Jl! '3 8 U,Oc ">.^ g"0 c I- 3 O i> 5 60 R^fc o a E -0 3 * S'cb ^ CU >. i! B Flanagan silt loam and Drummer clay loam asso- ciated (154-152) Uncorrelated Brown Silt Loam and Black Clay Loam associated; devel- oped from 40-65 inches of loess over calcareous, slow- ly permeable, silty clay loam till (no official num- ber assigned) Saybrook silt loam (145) Saybrook silt loam, Lisbon silt loam, and Drummer clay loam associated (145- 59-152) Saybrook silt loam, Lisbon silt loam, and Drummer clay loam associated (145- 59-152) Ashkum clay loam to silty clay loam (232) Elliott silt loam and Ash- kum clay loam to silty clay loam associated (146-232) Hagener loamy sand (88) ot every farmer was able to re larly. Yields were calculated a and soil types were uniform, ulated. The tracts were then gi :re then figured for each soil tj he term "tract" refers to a far he difference between corn yiel er period ; about one-third is d igures in this column indicate often used for both hay and p re. Most of the reported alfalf hese percentages are averages owpeas instead of soybeans we ye was grown on Hagener loai Z 3 Sgii > H H rt .23 H U K ( o> o S'.a S co .0 "~ " cd cd M 00 00 00 J3 '^ O. ^ cd a; "5 C ^2 MAIN SOIL REGIONS OF CENTRAL ILLINOIS FIGURE 1 PARENT MATERIALS IN DIFFERENT REGIONS la, b, c Loess 70-300 inches thick, calcareous at 40-70 inches 2a, b Loess 50-80 inches thick, generally noncalcareous 3 Calcareous, nearly imperme- able clay till 4 Calcareous, very slowly per- meable silty clay till 5 Glacial outwash and lake- bed sediments 6 loess 40-75 inches thick over cal- careous permeable loam till 7 Loess, 40-65 inches, over calcareous, slowly permeable silty clay loam (HI 8a, b Calcareous permeable loam till 9 Calcareous, slowly permeable silfy clay loam till 10 Predominantly sandy glacial out- wash and terrace deposits Region 1 is divided into three subareas because it is so large and informa- tion for some soil types is not complete in every area. Subareas in Regions 2 and 8 are widely separated geographically; the climate in 8a and 8b is different enough to affect yields. For crop yields on soil types in various areas see Table 1, pages 375 to 377. 1947] PRODUCTIVITY OF CENTRAL ILLINOIS SOILS 379 Characteristics and Location of Soil Types In central Illinois there are many different kinds of soil, which vary greatly in characteristics and productivity. Most of them, however, are very productive, especially for grain crops like corn. Level to gently sloping dark prairie soils occupy more than three- fourths of the area in this section of the state. Light-colored timber soils occur near the streams. Altho most of the surface soils have either a silt loam or clay loam texture, limited areas of sandy soils occur within and near Kankakee, Mason, Henderson, and White- side counties. As is apparent from Table 1, many soil types occur on the farms that have been mapped, altho the number of types on a single farm is generally small. The types for which records of crop yields are available are described in Table 2. This table indicates how low or high each type is in organic matter, whether the areas are sloping or level, whether there is likely to be much erosion, how permeable to water the subsoil is, whether crops are likely to resist drouth, and how workable the soil is. Each of these characteristics is im- portant to the operator or owner of a farm or to a prospective buyer. The map on page 378 gives an idea of the location of the major soil regions. It also indicates the kind of "parent" material from which the soils of the different regions have been derived. Table 1 and the map together form a picture of the major soil conditions of central Illinois. How Management Practices Alter Crop Yields That each soil type varies greatly in productivity according to the kind of management given it is shown in Table 1. Hybrid-corn yields on Swygert silt loam and Bryce clay loam to clay, for ex- ample, were 71 percent higher under good management than under poor management. Many different practices help to account for the yields which farmers are getting under good management. The ones which are given main consideration in this study, however, are cropping sys- tem and soil treatment. The kind of cropping system and soil treatment which a farmer uses are pretty good clues to his whole 380 BULLETIN No. 522 [March, "B 8"? .is .is Cfl C3 O | o o -S < O ? BO BO BO 00 M BO +s O O *> >-> o O 2 u "o "o o o u o *~ *~ o o o o o .h "o "o *< o to o o o o o M Ex* 15 O ~~'-"~ -'-"" O O t* O g - " o M BO **! M a u (J O O 2 2 2 CO e J3 2 os b "*"* *o "o h "o "o "o "o o .i .b "o .h .b _j, " "g * i i 1"! I* fe II o 'S3 o o o o o O fc O O O ft< (2 1 II Io5o 2 K HH J2 5 i - J o o o o >> .ti2. 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JB J3 J3 JC H _BO M BO "BO BO ^ .60 _M BO BO 2 2 2 2 H iS JB 3 2 2 2 " " V. ** o o o 2222 o o K * cd Jj *-> E E E E E E E E E E E E E E M ^ M ca c 3 3 3333 33333 33 3 H S cj H8 1 T3 T3 i ^ 173 * '5 m .*j 'S -J u TO B "^ m ^ ^S " ^- u< ! fi "Q 'S W co 4) C rt * ~ .^ _^ "5 * GJ C OT fc E . 2 t; g 3 2 | S E | rt fc fc "S rt 2 | 1-2 S f 1 * 2 2 S U H S tc 3 u? Be 1 K J5 W u B Q E |d oo -> n o a /-. oo oc - t- ^ vo - 00 **J 3 *o d 13 "O +* fO .13 O cfl 5 o M (5 CU b- O O b o * " "& -O I. o 8 8 8 '3 8 - 01 M Resistance to drouth Fair to g Fair to g g o O Good to Good Fair to g O I ; gently slo and draina w ^ u % _o *i o a ,' d ^ ^ m o ^~ S & 01 V V o> u i CO Si ii 2 rt 2 2 2 o S i S 8 D S3 m a >. O J; g j T3 o o 1 8 ">. * i S > ^ 53 S * * s "3 5 9 / s 2 ~ 2 ^ .y =3 O C eg C * L> 111 o ^ | 9 w o Z ei 60 '" 8 C 'S 1 3 3 i'l' 5 | | bo O 3 w^ii- M c s "S "c 5 ; ">. ft 2 'a o 3 ^ u bo _ S "Z 'a 'ft _o >> bo o.S | 5 C t 1 . xture a i. M c> j O Is j* _>. _>. I > bO^i ^ tH i 1 S s t H "o g S S g "o S M i_ _o 1 1 - o S z 2 Z O S > z *** "a N "^ t JZ J2 o 2 t 1 11 bo hd .S 8 c 01 ** .- 2 X . 2 M z * u o U -M 'S Su c lium lium to O S E 3 E J= U 1 1 ^K o 1 Ii -^ *m K 3 a o S be bfi 4> 0> U M S 13 3 O c o SS ic S S S 5 ^ ft .22 2 "5. 8 c a < a 1- flj 1 w a 3 XI US u ! I | B I | 0. ^ 3 T - - i o n fc > associated . . . Herrick silt loam joliet . . . Swygert silt loam to silty clay loam and Oquawka .... Bryce clay loam to clay associated. . . . . Hagener loamy sand Plots were treated with RLPK: that is, with crop residues (R), limestone (L), rock phos- phate (P), and potash (K). A good crop rotation is used on each field. b Wheat was grown on the Oquawka field instead of oats. Oats are not included in the rotation. 386 BULLETIN No. 522 {March, loam to clay. Farmers who practiced good management got practi- cally the same yields as those obtained on the experiment field at Joliet. Oat yields on the farms, however, were only 66 percent as high as those on the experimental plot. Hybrid corn yields were 84 percent as high as the Joliet yields. On associations of Muscatine silt loam and Sable silty clay, yields obtained by farmers who used good management also fell short of the experimental results. Yields of open-pollinated corn, hybrid corn, and oats were only 72, 76, and 81 percent as high on the farmers' fields as on the Kewanee experiment field. Farmers' yields of oats and hybrid corn on soil associations that included Herrick silt loam were, even under good management, considerably below yields on the Carlinville plots. Altho no figures are available in Table 1 to show results under good management on Hagener loamy sand, the difference in hybrid-corn yields under fair management on farms and under best management on the Oquawka experiment field are also of considerable interest. A number of things help to explain why farmers' yields thus far have usually been lower than those on the University's soil experiment fields: 1. Most farmers who have adopted good management prac- tices have done so only within the last 10 or 20 years, while the RLPK plots have been in continuous operation for 30 to 35 years. Many farmers have not practiced good soil management long enough to obtain maximum yields. 2. Since farm fields are much larger than the experimental plots, soil conditions are often more variable. It is therefore harder to be timely in field operations. 3. Harvesting losses are greater on farmers' fields than on the soil experiment fields. Yields reported in Table 1 for good management were produced primarily under a legume - limestone - rock-phosphate system of management. Soil investigations show that more intensive fertiliza- tion greatly increases the yields of some crops. Production of wheat and corn, for example, can be increased by the use of soluble ferti- lizers under proper conditions. 1947] PRODUCTIVITY OF CENTRAL ILLINOIS SOILS 387 Achieving Efficient Production on Your Farm The figures just given show what can be done. The next thing to know is how to do it. Briefly, these are the basic steps in a good soil-improvement program: 1. Get all the information you can about each soil type on your farm. Know all its characteristics. Only then can you use the land in the most effective way. Do not be content with 50 bushels of corn to the acre on a field that will produce 75 bushels. On the other hand, money and effort can be wasted in an attempt to get higher yields from a soil than it is capable of producing. It may be that the subsoil is heavy, or that the soil is drouthy, or that there is some other characteristic that cannot be corrected without too much money or labor. The effects of differences in soil and in management on yields BUSHELS OF CORN PER ACRE 40 60 Saybrook, Lisbon, and Drummer associated Clarence and Rowe associated Hybrid corn yields on two groups of farms in the northern part of central Illinois show what good management will do on some soils in that part of the state. While the better practices gave worth-while increases on an asso- ciation of Clarence silt loam and Rowe clay loam to clay (Region 3, Fig. 1), yields were not so high as on the association of Saybrook silt loam, Lisbon silt loam, and Drummer clay loam (8b on map). Reason for the lower productivity of the Clarence-Rowe association is a heavy clay subsoil. Figures are averages for the years 1937 thru 1944. (Fig. 2) 388 BULLETIN No. 522 [March, of hybrid corn are illustrated in Fig. 2. On one group of farms the soils consisted of an association of Saybrook silt loam, Lisbon silt loam, and Drummer clay loam. On another group the soils were a mixture of Clarence silt loam and Rowe clay loam. Good manage- ment, compared with fair management, increased the yields on the first group of farms from 57 to 71 bushels an acre. It increased the yields on the second group of farms from 40 to 51 bushels. (These figures are averages for eight years, 1937 thru 1944.) Altho both groups of soils responded to good management, it is clear that the second group has a lower limit to its yields than the first group. The fact is that Clarence silt loam and Rowe clay loam have a clay sub- soil which is nearly impermeable to water and air and which the roots of crops can scarcely penetrate. This is the main difference between these soils and the Saybrook-Lisbon-Drummer soils. All are dark prairie soils and all occur on nearly level to gently sloping topography. 2. Keep farm records each year. Good records are the only sure basis for comparing your crop yields with what others get on similar soils. People who do not keep yearly records are likely to remember the high yields in favorable years or on some especially good field and to forget the lower yields in other years or on other fields. Nothing less than a five-year average will give a figure worth comparing with the twenty-year averages in Table 1. Weather, for one thing, varies too much from year to year. 3. Examine your management practices. If your yields are below those that other farmers are getting from the same soil type, find the reason. Test your soils to see whether they are acid or low in available phosphorus and potassium. Check your cropping sys- tems ask yourself whether they will support high yields over a long period without harming your soils. Are you using the best cultural practices time of plowing, method of seedbed prepara- tion, rate of seeding and the best crop varieties? 4. Make necessary changes. Merely finding out what is hold- ing down crop yields won't increase them. The next step, therefore, is to translate this information into action to make out a definite crop- and soil-management plan on the basis of your findings and put it into operation. 1947} PRODUCTIVITY OF CENTRAL ILLINOIS SOILS 389 There is no regular order in which changes should be made, for conditions vary from one farm to another. Usually, improved cul- tural practices should be adopted first since they take very little time or money in relation to the yield increases which they produce. The adoption of a good rotation, including the proper kinds and acreage of deep-rooted legumes, requires a sweet soil. It is therefore necessary to apply limestone on acid soils before it is practical to make changes in the cropping system. Correcting phosphorus and potassium deficiencies is normally the next step in improving crop yields. The kind, amount, and method of applying these fertilizers will depend on the soil tests, cropping system, and the amount of money available for soil treatment. Your farm adviser will be glad to help you plan the best crop- and soil-management system for your farm. There is good reason to believe that farmers can look forward to getting higher yields in the future than they have obtained to date. Increased yields will, however, require the skilful combining of improved crop varieties with better cultural practices and better soil management than most farmers have applied in the past. SUMMARY Most farm lands of central Illinois are productive when well managed. They consist of many different soil types, of which the most common are described in this bulletin. The types which have been studied are located in 10 major soil regions, a region con- sisting of an area with the same underlying "parent" materials. Long-time records kept by farmers in central Illinois show how- much crop yields differ from one soil type to another. These records show too the extent to which poor or fair crop yields can be in- creased by better farm practices. The records analyzed in this study cover 444 different tracts (farms or parts of farms with uniform soil and management) and extend over periods ranging from ten to twenty years. Yields from four of the University's soil experi- ment fields show still further possibilities in some of these soils. The information in this bulletin will enable many farmers in central Illinois to measure the efficiency of their production prac- tices. Those whose yields are below the best will find suggestions for bringing them up to a more profitable level. The question HOW PRODUCTIVE ARE THE SOILS OF CENTRAL ILLINOIS? is answered in this bulletin by showing what crop yields farmers themselves are getting from the most important soil types in this area. Carefully kept records dem- onstrate what can be expected under good management as contrasted with fair man- agement and poor management. Any farmer whose yields do not come up to the best shown for his soil type is probably not realizing the full possibilities in his farm. He will find it worth while to review his production practices and plan a definite program of improvement. 10M 3-47 34440 UNIVERSITY OF ILLINOIS-URBANA