/f - rOR'r Issued March .">, 1900. U.S. DEPARTMENT OF AGRICULTURE, BUREAU OF PLANT [ND1 STRY Circular No. 24. B. I GALLOWAY. Chief of Bureau. ALFALFA IX CULTIVATED HOWS roll SEED PRODUCTION IN SEMIARID REGIONS. CHARLES .1. BRAND, Physiologist, AND J. M. WESTGATE, Agronomist, Bureai of Plant [ndt go bi . WASHINGTON : GOVERNMENT PRINTINQ OFFICE : 1909 BUREAU OF PLANT INDUSTRY. Physiologist and Pathologist, and chief of Bureau, Beverly T. Galloway. Physiologist and Pathologist, mid Assistant chief of Bureau, Albert F. Woods. Laboratory of Plant Pathology, Erwin F. Smith, Pathologist in Charm'. Fruit Disease Investigations, Morton B. Waite, Pathologist in Charge. Investigations in Fdrest Pathology, Haven Metcalf, Pathologist in Charge. Cotton and Truck Diseases and Plant Disease Survey, William A. Orton, Pathologist in Charge. Pathological Collections and Inspection Work, Flora W. Patterson, Mycologisl in charge. Plant Life History Investigations, Walter T. Swingle, Physiologist in Charge. Cotton Breeding Investigations, Archibald D. Sharael and Daniel N. Shoemaker. Physi- ologists in Charge. Tobacco Investigations, Archibald D. Shamel, Wightman W. Garner, and Ernest II. Mathewson, in Charge. Corn Investigations, Charles P. Hartley, Physiologist in Charge. Alkali and Drought Resistant Plant Breeding Investigations, Thomas II. Kearney, Physi- ologist in Charge. Soil Bacteriology and Water Purification Investigations, Karl F. Kellerman, Physiolo- gist in Charge. Bionomic Investigations of Tropical and Subtropical Plants, Orator F. Cook. Bionomisi in Charge. Drug and Poisonous Plant and Tea culture Investigations, Rodney II. True. Physiologist in Charge. Physical Laboratory, Lyman J. Briggs, Physicist in Charge. Agricultural Technology, Nathan A. Cobb, Crop Technologist in Charge. Taxonomic and Range Investigations, Frederick V. Coville, Botanist in Charge. Farm Management, William .1. Spillman, Agriculturist in Charge. drain Investigations, Mark Alfred Carleton, Cerealist in Charge. Arlington Experimental Farm and Horticultural Investigations, Lee C. Corbett, Horti culturist in Charge. Vegetable Testing Gardens, William W. Tracy, sr.. Superintendent. Sugar-Beet Investigations, Charles 0. Townsend, Pathologist in Charge. Western Agricultural Extension, Carl s. Scofteld, Agriculturist in Charge Dry-Land Agriculture Investigations, E. Charming Chilcott. Agriculturist in Charge. Pomological Collections, Gustavus B. Brackett, Pomologisl in Charge. Field Investigations in Pomology, William A. Taylor and G. Harold Powell, Pomologists in Charge. Experimental Gardens and Grounds, Edward M. Byrnes, Superintendent. Foreign Seed and Plant Introduction. David Fairchild. Agricultural Explorer in Charge. Forage Crop Investigations. Charles V. Piper, Agrostologist is Charge. Seed Laboratory, Edgar Brown, . Botanist in Charge. Grain Standardization, John D. Shanahan, Crop Technologist in Charge. Subtropical Garden, Miami. Fla., P. J. Wester, in Charge Plant Introduction Garden, Chico, Cat, W. W. Tracy, jr.. Assistant Botanist in Charge. South Texas Garden, Brownsville, Tex., Edward C (Jreen, Pomologisl In Charge. Farmers' Cooperativt Demonstration Work, Seaman A. Knapp. Special i-genl iii Charge Seed Distribution (Directed by Chief of Bureau), Lisle Morrison. Assistant in General Charge. Editor, J. E. Rockwell. Chief Clerk, James E. Jones. [Cir. 24] 9 B. P. I ALFALFA l\ CI LTIVATED ROWS FOR SEED PRO- DUCTION IN SEMIARID REGIONS. INTRODUCTION. The growing of alfalfa in cultivated rows for seed is of more recent origin in this country than is the production of hay l>v this method. John Spurrier, in a book entitled "The Practical Farmer," published at Wilmington, Del., in L793, appears to be the firs! Amer- ican writer to mention the growing of alfalfa in cultivated rows. The cultivation was designed to retard the development of weeds, which often prove verj destructive to broadcasted seedings of a I fa I fa in the Middle and South Atlantic States. This method is -till prac- ticed to a slight extent iii a few places in the South, where, however. the climate is too humid for the successful production of alfalfa seed. -in observations made during the summer of 1906 by investigators in this Bureau, including the present authors, ii became apparent that the margin between success and failure in profitable alfalfa growing in regions of light rainfall is often so narrow, even when the most drought-resistant strains are used, as to be determined almost wholly by the methods of cultivation em- ployed. Experiments were inaugurated to lest 1 1 1 * » value of various methods "i seeding alfalfa, including thai of sowing ii in rows properly spaced to per- inii ..f intertillage. The results obtained in these preliminary experiments and those secured by practical farmers in the semiarid sections on a Held scale indicate clearly thai increased yields of seed will follow the use of this method. The value of row seeding and cultivation in hay production is also being investigated. The area seeded to alfalfa is increasing so rapidly thai it is not possible to secure enougb home-grown seed to supply the demand. As a result, several million ( - of foreign seed of various grades, bul often of rather inferior quality, are imported annually. Ii is believed thai the developmeul of seed production in cultivated rows will go far toward meeting the home demand with a domestic supply and thai at the same time a considerable advance in the development of the semiarid sec- tions of the country where farming operations are handicapped by lack of moisture will he brought about, for these reasons it is thoughl advisable to make the details of this method, so far as they have been developed, available to ih..-.' now c lucting farming operations in those regions of lighl rainfall where the method promises to give the host result-, l'.. T. Galloway, Phys- iologist mill Pathologist, and Chief 'if Bureau, [Cir.24] 3 4 ALFALFA IN CULTIVATED ROWS FOR SEED. In England as early as 1730, Jethro Tull, the inventor of the drill and the originator of tillage of farm crops in the modern sense, advocated and practiced the growing of alfalfa (lucern) in rows. His teachings first appeared in his " Specimens.' 1 Later, in 1829, these were republished by Cobbett in a work entitled " Tull's Horse- Hoeing Husbandry." What was apparently the first attempt to grow alfalfa for seed in cultivated rows in this country was made by what was then known as the Section of Seed and Plant Introduction of the United States Department of Agriculture. Several contract fields of Turkestan alfalfa were seeded in wide rows in different parts of the Great Plains area in L903. The poor seeding habits of Turkestan alfalfa when grown in this country, together with the fact that the plants were grown much too thickly in the rows, greatly handicapped the logical development of this method. The application of the row method of cultivation has been suggested by a number of American experimenters, including Prof. W. J. Spillman," Prof. W. M. Hays, 6 Prof. W. A. Wheeler.' Mr. W. M. Jardine,' 7 and Mr. C. S. Scofield. c Of these only Professor Wheeler has used the method on an experimental and field scale and his results arc confirmatory to those presented in this paper. The work on which the conclusions here presented are based has been conducted at various experiment farms of this Bureau and on the farms of Mr. Lewis Brott, Sextorp, Nebr. ; Mr. E. Bartholomew, Stockton, and Dr. W. A. Workman, Ashland. Ivans. Bow cultivation for seed growing has been in use for a number of years in the vineyard regions of southern Germany, particularly in Baden and Bavaria, in the production of seed of Alt-Deutsche Friink- ische luzerne, a well-recognized German strain. It is said that alfalfa i- grown in cultivated rows for seed in parts of Russia, where hand cultivators prove an effective and practical means of holding the weeds in check and of conserving soil moisture. The method has been employed for a number of years by Dr. L. Trabut, government botanist of Algeria. Fairchild ' describes a " Annual Report for 1903 of Minnesota State Agricultural Society. 1904. h Ilanly Alfalfa in Minnesota. Press Bulletin No. 20, University Experiment Station, Minnesota. 1904. c Forage 1'lanis at the Highmore Substation, 1906. Bulletin No. mi. South Dakota Agricultural Experiment Station. 1907. ''Arid Farming Investigations. Bulletin No. 100, Utah Agricultural Experi- ment Station. 1906. i Issued in 1907.) "Dry Farming in the Ureal Basin. Bulletin No. 103, Bureau of Plant In- dustry, U. s. Department of Agriculture. iui>7. ' Fairchild, David. Cultivation of Wheat in Permanent Alfalfa Fields. Bul- letin No. 72, part 1, Bureau of Plant Industry. U. S. Department of Agriculture. 1904. [Cir. 24] ALFALFA IN CULTIVATED ROWS FOB SEED. 5 method of growing wheal between alfalfa rows in Algeria under light rainfall, where ii has been found possible to produce a crop oli wheal between the wide rows of alfalfa in alternate years. The practical value of this method for the semiarid portions of the United States was indicated in the publication mentioned, without, however, making any direcl reference to the seed-producing possibilities of alfalfa -own in cultivated row- under such conditions. PRINCIPLES UNDERLYING ALFALFA SEED PRODUCTION. Although alfalfa has been grown increasingly in the West since L854 or l v -">-"' little has been done to develop a rational -red industry. Ii is a matter of common observation that even in recognized producing sections the seed crop is very uncertain. A study of some of the factors that cause success or failure has indicated some of the underlying principles affecting the production of profitable seed crops. En Bulletin 118 of this Bureau " at lent ion was directed to the fact that cultivated alfalfa is not a homogeneous species, but is com- posed of numerous races, -trains, varieties, and even subspecies. These vary greatly in many characters, and especially in their seed producing capacity, no pure varieties of known high value comparable with those we have of corn, wheat, and other crops having as yet been established. It has also been noted that the individuals constituting these diverse races, elementary species, or whatever they may be called, exhibit great variation among themselves. This is partial larly true of their ability to set seed. To overcome the source of error resulting from this diversity in individual plant:- the method of vegetative propagation described by Westgate and Oliver, 6 of the Bureau of Plant Industry, has been used in a portion of this work. It ha- often been noted that a- a rule i-olated alfalfa plant- set seed far more profusely than those in all bul the thinnest stands. Observations on this point have been made in various parts of the (iivat Plains and intermountain area- and in the farther Southwest. On the Arlington Experimental Farm, near Washington, I). ('.. an experiment was performed t<» determine the effect of different de grees of isolation on the seed-setting ability of alfalfa. In this experiment, cuttings from a heavj seeding plant were rooted in the greenhouse and later set out at varying interval.-. Inasmuch a- these plant- were propagated vegetativelj from the same mother plant. the\ did not -how the individual variation •mentioned above that •Brand, Charles .1. Peruvian Alfalfa: A New Long-Season Variety for the Southwest. Bulletin No. its. Bureau of Plant industry, I". s. Departnienl of Agriculture. 1907. 'The Application of Vegetative Propagation to Leguminous Forage Plants. Bulletin No. 102, part I. Bureau "i Plant [ndustry, U. s. Departmenl of Agri- culture. 1907. [Or. imj 6 ALFALFA IN CULTIVATED ROWS FOR SEED. would have entered into the experiment had seedling plants been utilized. The plants occupying a space equivalent to a 7-inch square pro- duced a maximum of 38 pods, while those having at their command a space equal to an 11-inch square produced a maximum of 96 pods. The highest number of pods formed on plants grown in rows 39 inches apart and 18 inches apart in the rows was 505. It will be noted that the yields were in almost direct proportion to the areas occupied. However, it was evident that the plants hav- ing the greatest distance between them had not utilized fully their allotted space. This was accounted for by the fact that it was their hist season's growth. An adjoining two-year-old cutting from another plant of similar seed-producing tendencies produced 2,080 pods, and this without utilizing all of the space of 18 inches in the 39-inch row assigned to it. Although part of this difference may have been due to inherent capacity, the chief explanation for it must be sought in the firm establishment of the plant and its greater maturity. Just why the isolation of plants increases the production of seed has not been fully determined, but it is apparent that one of the factors involved is the increased amount of sunlight available to the plant. It has often been observed that trees grown on the banks of irrigation ditches in alfalfa fields or along the margins of fields always interfere with normal seed production as far as the influence of their shade extends. In the course of an experiment on the seed setting of alfalfa it was found that partial shading materially re- duced the quantity of seed produced by plants not already receiving more than the optimum amount of sunlight. When alfalfa plants have sufficient space for full development they have approximately equal illumination on ail sides. The effect of this is well shown in figure 1. In this case seed has developed over the entire plant and not at the top only, as is the case in thick stands, where there is more or less competition for the requisite amount of light and air. With the plants so far apart that when fully developed they barely occupy the ground the potential seed producing surface exposed on an acre is nearly double that of a thick stand. In the latter, because of crowding, the plants are unable to produce seed, apparently on account of shading by closely associated individuals. „ In addition to the injurious influence of shade, the crowding of plants interferes with seed production by depriving Hie plants of sufficient moisture to enable them to mature their seed properly. This, of course, is true only in areas of light rainfall. On the other hand, in sections where irrigation is practiced thick' stands l>\ check- ing evaporation bring about such moist conditions in lields as to [Cir. 24] ALFALFA IN CULTIVATED ROWS FOB SEED. 7 promote unfavorable conditions and so prevent maximum yields of seed. The basal shoots which usually appear when the plant begins to i'l are developed at the expense of the seed crop. The energy that should be devoted solely to the maturing of the seed is diverted by tlii- new growth. Perhaps the mosl important factor influencing I ?%&*%& Ucuvilj seeded Isolated alfalfa plant grown near Washington, D. C, where the clmatlc conditions are much more unfavorable to the production of alfalfa seed than in the semiarid sections, the development of these basal shoots which are to form the succeed- ing crop is the wain- contenl of the soil. If the moisture supply be ample, the basal shoots commence their growth about the time the plant comes into bloom. This is disastrous to the seed crop, and for this reason it is necessary thai there be a sufficient shortage of tnois- [Clr.24] 8 ALFALFA IN CULTIVATED ROWS FOR SEED. ture at this time to retard or prevent altogether the development of these shoots. In the seed-producing sections of the more humid parts of the Great Plains area profitable crops of alfalfa seed are usually obtained only in the occasional seasons of drought so extreme that the yield of other crops is greatly reduced. Drought is used here in a qualified sense. There must, of course, be enough moisture in the soil to enable the seed to mature fully ; otherwise it will be deficient in germinating power. On the other hand, the soil must not contain enough moisture to force into growth the crown buds that produce the succeeding crop. The favorable conditions for the production of alfalfa seed which prevail in the semiarid regions are due principally to the presence there of a favorable adjustment of the supply of moisture in the soil to the moisture requirements of the plant when grown for seed. This is especially true when the plants are grown in cultivated rows, as the moist ure content of the soil can then be regulated to some degree by proper cultivation. THE RELATION OF INSECTS TO THE SETTING OF ALFALFA SEED. Insect visits are essential to the proper pollination of the alfalfa flower. If fertile seed is to be produced in any quantity it is neces- sary that a certain explosive mechanism within the flower" be re- leased. The release of this mechanism, whether it be accomplished by insects or otherwise, is popularly called " tripping." Experiments and observations h both by the writers and by other in- vestigators indicate that practically no seed is produced if the flowers are not tripped. Bumblebees (Bombus spp.) are generally believed to he the most efficient of all insects in setting off the explosive mech- anism, and hence in bringing about pollination. Honeybees, though not nearly so effective as bumblebees, should not be underrated in this connection. It is a practice in somef parts of the country to place beehives along the margins of alfalfa fields intended for seed. Bee keepers follow with their colonies fields planted for seed, for the " By Hie explosion of an alfalfa flower is meanl (he snapping out of the stamens and pistil from the wings and keel, which had hitherto enveloped them, to a new position against the standard. This lakes place when certain insect visitors insert their nectar-gathering organs into the flower. The un- pad of Hie stigma and stamens againsl \\\>- body of the insect appears to have a i leasl three immediate and important results: i l » The wounding of the stig- matic surface of the pistil, making it more susceptible to fertilization: ti'i the contact of I his sensitive surface with pollen home on the insect's hody from previously visited flowers; and (3) the dusting of new pollen on the insect which will function in pollinating (lowers subsequently visited. '■The particular Investigations in regard to the relation of the tripping of the alfalfa flower to (he setting of seed, upon which (his is a preliminary report, have been conducted principally by the junior author of this publication. [CU-. 24] ALFALFA IN CULTIVATED BOWS FOB SI 9 purpose of getting the honey. This is mutually beneficial, as larger yield- of both seed and honey result. Wild bees (Andrena spp. and Megachile spp.) and various butterflies are also valuable agents in pollinating al fal fa flowers. That the explosh f al fal fa flowers may be accomplished by other mean- than insect visitation is quite well known. The insertion of a more or less pointed instrument into the throat of the corolla has often been resorted to in studying the tripping mechanism of indi- vidual flowers. Roberts and Freeman" describe a method of ex- ploding flowers in large numbers by rolling the head carefully but firmly between the il b and the first and second fingers. This trips the flowers then at the proper stage of maturity. Tripping on a still more wholesale scale may be done by grasping the entire plant be- tween the hand- at successive intervals. In this case it is besl to work from the bottom toward the top of the plant, exerting the required pressure at the proper intervals. It has been found that flowers tripped by any form of manipula- tion set seed readily, while other (lower- left unexploded and from which insects are excluded rarely set seed. A.s only a slight pressure on the keel is necessary to trip the flower artificial method- may be resorted to as a mean- of supplementing the natural process as accomplished by insects. In an experiment at the Arlington Experimental Farm in which the method mentioned of exerting pressure successively over the whole plant was used, the yield of pod- was increased 25| per cent over adjoining row- not thus treated. At Chico, ( 'al.. an increase of L29 per cent in the number of pods resulted. Although greater seed yields also result, two experi- ments at least indicate that the increase in the number of seeds is not in as high proportion as is the increase in the number of pods. Further experiments and more exact observations under varying conditions in different sections will be necessary to determine just when sufficiently increased yields of seed may be expected to justify the expense of the undertaking. Any alfalfa seed producer ma\ test this method experimentally on a small scale. A hundred plants may be counted off and tripped by hand three times a week during the blooming period, using either of the methods previously described. Another hundred plants of similar seeding habits should be left to be exploded by insects. An\ greater produc- tion of seed on a given number of head- on the manipulated plants a-* compared with the same number of heads on those not so manip- ulated may with reasonable safety be attributed to artificial tripping. If the increased yield- which have been obtained in the prelimi- nary experiments arc equaled in ~<->-i\ producing sections, it i- | Bulletin No. 151, Kansas Agricultural Experiment Statiou 70451— < ik. -I 09 -2 10 ALFALFA IX CULTIVATED ROWS FOR SEED. able that means will be devised for exploding the flowers on a large scale. The only sections in which this method will be likely to prove profitable are those where for any reason proper insects are not present in sufficient numbers to explode a large percentage of the HoAvers. AREAS TO WHICH THE GROWING OF ALFALFA FOR SEED IN CULTIVATED ROWS IS ADAPTED. The experiments thus far carried out in the production of seed in cultivated rows have been located principally in the semiarid portions of the Great Plains, in the intermountain area, and in the Palouse country of eastern Washington. The field shown in figure 2 Fig. 2. Alfalfa in cultivated rows for seed, near Stockton, Kans. In the more mature rows shown at the right and left the first crop was devoted to seed production, while in the rows in the middle of the illustration later growths were left for seed. Photo- graphed July i>, 1908. is on (he farm of Mr. E. Bartholomew, near Stockton, Ivans. It is probable that the method will be found to be adapted to many of the semiarid sections of the country which have a rainfall of from 1 1 to l 20 inches, and possibly also to irrigated sections where the supply of water is insufficient for the production of full hay crops. It is also recommended lor trial in irrigated sections having water for hut half or less of the normal acreage of alfalfa in the district, and also for fields lying slightly higher than the ditch lines but which have the water level moderately near the surface. Experiments in humid sections indicate that even there row cul- tivation makes possible much higher yields of seed than are pro- [Cir.24] \i.i Ml A IN « II. I l\ A I ED ROM S FOB SEED. II (lured by fields -own broadcasl or drilled in the ordinary manner. Figure 1 -hew- the seed production of an individual plant at the Arlington Experimental Farm, where the average rainfall i- \'-'>\ inches. It is doubtful, however, whether even this method will insure the production of paying crops of alfalfa seed under humid condil ion-. Row cultivation under condition- of ample rainfall is more valuable a- a method id' weed control than for increasing seed yields. At the time when pud formation i- going on. a certain amount of dry weather and heat i- necessary to insure the greatest production of alfalfa seed, even w hen the plants arc isolated. This method promises to lie more successful in sections where the annual rainfall k from 1 ! in -J" inches than elsewhere. Where the precipitation ranges from •jo in l'."> inches thin seeding by broadcasting or drilling in the ordi- nary way may be preferable to row cultivation. Field- -own by either of these method- can he kept up at much less expense. Less frequent cultivation will he necessary, and when needed may he given with an alfalfa renovator or a disk, straight-toothed, or slant-toothed harrow. Under these method-, as in row cultivation, the stand inn-; be very thin if the best results are to he obtained. SELECTION OF SOIL. In the semiarid sections the ordinary arable land, such as i- used for the common farm crops, will prove well adapted to this work so far a- fertility is concerned. Ina-nnich as the child' purpose of culti- vation is moisture conservation, -oil- of large moisture-holding capacity should he used when there i- opportunity for choice. Care should he taken t\ the row method. LCir. _lj 12 ALFALFA IN CULTIVATED ROWS FOR SEED. PREPARATION OF THE SEED BED. The preparation of the ground should be such as to rid it as far as' possible of weeds and at the same time to provide a seed bed which has become well firmed by settling or rolling, or both. In the drier portions of the semiarid regions summer-fallowing the preceding season may be necessary to provide the soil with the moisture required to insure prompt germination of the seed. This implies keeping the field in the cleanest possible culture during the previous summer. Weeds must be controlled and proper tillage must be given after each rain. The soil mulch thus maintained will check evaporation and in the following year place at the disposal of the young plants the greater part of two years' rainfall. In the North, where spring planting is advisable, surface tillage must be continued until seeding time. In many cases it will not be necessary to summer-fallow if the field is devoted to a cultivated crop, such as corn, during the preceding year. In the Great Plains country, when the ground is plowed, immediate harrowing and rolling should follow the plowing. In addition, sub- surface packing is advised for all spring-plowed land, hut may often be omitted in the case of fall plowing, as natural settling sup- plemented by harrowing and rolling usually produces a sufficiently firm seed bed. If firming is not done there will be at the bottom of the new furrow a dry, porous stratum of the old topsoil. This condition, which is present in all freshly plowed fields where the Mil face is dry, may result fatally to the young alfalfa plants, as their roots can not make the necessary development in this layer, containing dry soil, clods, and air spaces. If the field is not to be left fallow long enough for harrowing and natural settling to make the ground sufficiently firm below, this injurious condition should be remedied by subsurface packing with suitable implements. It is necessary that there be sufficient moisture in the soil at seeding time to enable the jDlant to make a sufficiently rapid growth to permit of surface tillage without covering up the young plants. The purpose of subsurface packing is not to prevent loss of moisture, bui to reestablish the capillary column which was inter- rupted by the plowing under of the dry topsoil. Unless this is done the moisture from the lower soil can not reach the roots of the plant. Immediate harrowing also prevents considerable loss of moisture from the new topsoil. In regions where the greater part of the annual rainfall comes during the winter and where the ground does not freeze to a great depth or remain frozen for a long period, as is the case in a large pari of the intermountain area and in the southern part of the Great Plains, it may be undesirable to level and linn immediately after [Clr. 24] \i i \u \ i\ CULTIVATED i;>>\\ S FOB SEED. 13 plowing, as is indicated for the middle and northern Great Plains region. This applies onlj to fall plowed land. The reason Eorthisis obvious, as both these operations may work against the conservation of the winter precipitation by preventing penetration and promoting run off. Rough plowed land under the conditions described hold- a large portion of the moisture due to rain or melted snow and gives it ;in opportunity to soak in after each thaw. Spring-plowed fields in the intermountain area and southern Great Plains should be given the treatment previously indicated for similar fields in the colder por- tions of the ( ireat Plain-. A promising method of securing the desired seed bed, developed l>v Dr. W. J. Workman, of Ashland, Kan-., has been found to give satisfactory results on buffalo-grass sod. The principal difficulty in the growing of alfalfa in cultivated row- for seed is the weediness of the ground during the firsl season after seeding. This is avoided by the utilization of sod land. A L6-inch sod plow is used to cut a furrow -2\ inches deep through the sod, a stirring plow following immediately in the furrow left by the breaking plow and leaving a furrow about s inches deep. On the next round the breaking plow puts the strip of sod in the bottom of the deep preceding furrow. where it is completely covered by the new soil turned up by the stir- ring plow. The harrow i- kept at work to smooth and firm the ground as fast as it is turned, and the alfalfa is seeded with the grain drill while the -oil is still moist. THE PREVENTION OF THE DRIFTING OF SOIL. If the ground is so sandy as to be in danger of drifting or blow- ing during high winds, it is the best practice to seed alternate rows of oat- or barley and to make these rows run at right angles to the direction of the prevailing wind-. The first cultivation of the alfalfa plants will destroy this grain nurse crop, which should in no event he left long enough to injure the young alfalfa plant-. Another method of avoiding the danger of blowing out or drifting in a sandy -oil i- to sow the alfalfa with a walking garden drill between corn or sorghum row - after the last cultivation. This method ha- been tried with success under irrigation on the experiment farm conducted by the Office of Western Agricultural Extension near Fallon, Ne\. In attempting to use the method under dry-farming condition- careful attention must he given to the supply of moisture available lor both plant-, and a- it ha- not yet been put into actual practice in the -emiarid sections it should lir-t he tested on a -mall scale. A third method ha- been suggested l>\ Dr. 11. I>. Shantz, of the Office of Alkali and Drought Resistant Plant Breeding [nvestiga [Clr.24] 14 ALFALFA IN CULTIVATED ROWS FOR SEED. tions, Bureau of Plant Industry, which may prove useful when sod laud is used. This method consists of leaving narrow strips of virgin sod a( suitable intervals through the fields at right angles to the pre- vailing direction of the most destructive winds. A method applicable especially to old fields which show a tendency to blow during high winds has been suggested by Air. X. Schmitz, of the Office of Forage Crop Investigations, Bureau of Plant Industry. This method calls for the seeding of the alfalfa in shallow listed furrows running at right angles to the direction of the prevailing heavy winds. It is necessary that these furrows be shallow, or heavy rains which sometimes occur may bury the seedling plants. If the planting does not take place at the time of listing or if the planting attachment to the lister can not be adapted to this work, a corn drill or check-row planter may be used by making the necessary alterations in the plates, as suggested on page 15. This method of listing may also prove efficient in catching the snow during the winter preceding the planting. Spring harrowing will level the ridges if they are too high at planting time. CHOICE OF SEED FOR CULTIVATION IN ROWS. Other things being equal, seed from plants grown without irriga- tion should be used in preference to any other. The relatively small quantity required when this method is used justifies increased pre- caution and expense to obtain the best seed available. Some few strains of Turkestan alfalfa have given better yields of hay than the ordinary kind under semiarid conditions. However, none of them have shown satisfactory seed-producing capacity. Special dry-land strains of alfalfa that have been developed through unconscious selection in some of the older dry-farming centers of the West prac- tically always exceed in seed production the Turkestan and all other forms of alfalfa thus far introduced. Whenever these kinds can be secured they should be preferred by the farmer. Seed from the drier parts of western Kansas and Nebraska, from the dry farms of Cache Valley, and from the Levan Ridge near Xephi, Utah, will probably. produce the most satisfactory results. METHOD OF SEEDING IN ROWS. Several methods have been used in experiments, but the best result- have been obtained by sowing seed in rows about :'> feet apart. The distance between rows should be governed by the moisture supply that can lie counted on and by the width of the machinery available for use in cultivating. If seeding is done with an ordinary grain drill with shoes 8 inches apart, the stopping up <>f 1 out of every ■> holes will make I he rows l<> inches apart. If, on the other hand, ;3 out of [Cir. :>4] \U \l.i UN I I l.l IV \ i ED l.'"\\ S FOB S] 15 every I boles are stopped up, the rows will be 32 inches apart. The wider distance is recommended, especially in sections where the rain fall is verj scant. Ajiother method which has given good results, especially in hay growing, and which ma\ often prove useful where it is proposed to use the same field for both hay and seed production, is thai of sow- double instead of single row-. This can be accomplished by leaving 2 hole- open and stopping up 3 or I hole- aero-- the drill. The double rows will then he 8 inches apart, while the .-pace left for intertillage will lie 32 or |o inches wide. Experiments with this method which have been under way for two seasons on the San Antonio Experiment Farm of the Office of Western A.gricultural Extension indicate that this method will he useful under some con- ditions. It lias al-o been used with success under Professor Wheeler's direction on the State substation farm at Highmore. S. Dak. Any good garden drill will give satisfactory results. If such an implement is not available it may he found advisable to procure one for use in thi- work. \n ordinary corn drill such a- i- used in drilling corn in listed furrows can lie u-i'<\ by babbitting up the holes in the corn plate and drilling new one- of proper size to drop about 15 alfalfa seeds. If a blank plate is at hand, holes may he drilled into that large enough to drop from 1<) to 20 seed-. The germination value of the and all factor- that tend to lessen the ultimate number of plants niu-t he considered in determining how thickly to seed. The holes should lie close enough to drop seeds at intervals of IV 8 to 12 inches. Mr. Lewis Brott, a pioneer dry-land alfalfa seed producer in western Nebraska, ha- had successful results by using an onion seed plate in a corn drill. RATE OF SEEDING AND THICKNESS OF STAND. In mature stands of alfalfa in cultivated rows the plants should averaj I 1 foot apart in the row. To insure this, it is neces- sary that the plant- be much thicker at first, as their mortality under i\v\ conditions is very high. Satisfactory results have been secured by seeding the alfalfa with an ordinary grain drill so set that it would sow 12 pound- of seed per acre with all the hole- in operation. With I out of every •"> hole- -topped up. approximately 2jj pounds if seed to the acre will he -own. The stand in a cultivated row need he no thicker even at first than that of the row- in ordinary drilled held-, though the row- of the latter are usually only about s inches apart. Where the conditions [Cir.24] 16 ALFALFA IN CULTIVATED ROWS FOR SEED. are not favorable, it is usually best to seed more thickly at first than is necessary and to thin out the plants subsequently to the desired stand. As much as 7 pounds of seed to the acre have been sown in 36-inch rows without producing too thick a stand for satisfactory results during the first season. This rate of seeding is equivalent to 30 pounds per acre drilled in the usual way under conditions of sufficient moisture with the rows 8 inches apart. If difficult}' is experienced in making the drill feed slowly enough, it may be overcome for the most part by mixing corn chop with the alfalfa seed or by reducing the feed in the grain drill with strips of leather. Millet or other seed of similar size may be rendered ungerminable by heating thoroughly in an oven for several hours and then mixed with the alfalfa seed to aid in securing any desired rate of seeding. Sawdust and dry soil are also frequently used for this purpose. It is a very good plan to test the drill first on bare soil with the shoes not touching the ground. In this way it is possible to observe the rate at which the seed is being dropped, and thus a proper regula- tion of the seeding can be secured. There should be an average of from I to 10 plants to the running foot. It has been too often the case that the stand in the row has been too thick for the best develop- ment of the individual plants. In such instances cross-harrowing after a majorit}' of the plants have become well established will be found to be very effective in thinning out the stand. SEEDING IN CHECK ROWS TO PERMIT CROSS-CULTIVATION. Limited experiments with seeding in check rows indicate that with heavy seed-producing plants of satisfactory character very good yields of seed may be secured with hills 30 inches apart in the row. This distance permits of cross-cultivation, hut is rather narrow for most cultivating machinery. The plants being thus isolated on all sides, the production of a maximum seed crop is possible. Xo prac- tical means have yet been devised for seeding alfalfa in check rows on a large scale. It is probable that an ordinary check-row corn planter can lie adapted to this work. It would he necessary to bab- bitt up the holes in the plate and then rim them out to drop 10 to 20 seeds in a place. The surviving plants can later on be thinned to the best plant in the hill. The portion of the field shown on the right of the picture in figure 2 is sown in check rows. It is possible that alfalfa seeded in rows with a wheat drill could be thinned out to practically uniform distance- by cross-cultivation with an ordinary corn plow run at right angles to the rows. The plants, with (he ex- ception of a few midway between the two sets of shovels, would thus be destroyed. [Cir. 24] \! I \i.l \ l.\ ( ll.i i\ \ i ED BOWS FOB SJ 1 7 TIME OF SEEDING. Early spring seeding will usually yield the besl results, as more favorable moisture conditions for the germination and growth of the young plants are present at this time. However, if the soil can be broughl into proper condition of tilth and moisture content, seeding can take place during the late summer if the danger of winterkilling is ii< ii too great. In a climate of moderate severity if a 0-inch growth is made during the fall the plants will probably go through the winter safely, and will -tart out the following spring in much better condition to compete with the weed- than will spring-seeded plant-. In semiarid regions it i- usually impracticable, however, to seed alfalfa in late summer or early fall owing to the lack of moisture necessary to insure prompt germination. In the Dakota- and .Montana. June seeding will probably give the hot results. If seeding i- deferred until early summer and the soil is harrowed or otherwise treated to keep it in proper tilth, nio.-t of the weed -cimI- near the surface will germinate. The las! cultivation given the land before the alfalfa is sown kill- this young growth, thus greatly reducing the trouble with weeds during the firs! season. TREATMENT OF THE STAND THE FIRST SEASON. The well-settled moist seed bed necessarj for the growth of alfalfa furnishes ideal conditions for the rapid development of weed-. Sev- eral cultivations are necessary to hold even those of the first season in check. A 2-rovt cultivator provided with narrow shovels is the most practicable machine for this work. Fender-, or. better, a bos sled. should he provided to avoid the danger of covering up the young alfalfa plant-, and care should he taken to ridge up the rows as little as possible, a- this will interfere with mowing operation-. After the stand has become firmly established ridging can he readily corrected by cross-harrowing. Mr. Bartholomew ha- devised a harrow id' adjustable width which is very useful both in controlling weed- and keeping up the necessary surface mulch. The -tand may he much thicker during the first season than in sub- sequent seasons. Some "I' the plants will be destroyed by cultivation, and the less drought resistant and less hardy plant- will he killed by the dryness of the summer and the cold of the first winter. Unless plant- are so thick a- to crowd one another no thinning should ho done h\ cross-harrowing while the plant- are -till -mall. Experiments in eastern Colorado, eastern Washington, and Cali fornia indicate that under \i-r\ < 1 1\ condition- the plant- should not he clipped the firsl season if they are to make their greatest indi- vidual development. On the other hand, in the Willamette Valley of Oregon it ha- Ken found necessary to clip during the first season. In nn\ event, clipping, if undertaken at all. should he with the sickle [fir. 24] 18 ALFALFA IN CULTIVATED ROWS FOB SEED. bar of the mower set high, and probably should not be resorted to unless it is found impossible to hold the weeds in check by the ordi- nary cultivations. As there is still some uncertainty regarding clip- ping the first season, it is suggested that farmers leave a portion of the field undipped to demonstrate the best practice under various conditions. Should the plants begin to set seed, clipping will he advisable. In cases where it is practicable, hand weeding or hoeing maj' be used to supplement horse cultivation. TREATMENT OF THE STAND AFTER THE FIRST SEASON. The treatment of the stand during subsequent seasons will differ very little from that of the first season. The plants should average not more than four to the foot. In the spring or early summer of the second season, if the natural methods of thinning out have not been severe enough it will be necessary to harrow crosswise lightly to accomplish a further reduction in thickness of stand. It may also be worth while to go over the rows with a hoe as soon as the plants commence to set seed, cutting out undesirable individuals. This operation will involve considerable time and expense. However, as there is such great variation in the value of different plants, this procedure may be justified at least until strains of known high value for the conditions at hand have been selected and propagated for use on a field scale. Row-sown alfalfa fields that have not been properly thinned will not give maximum seed yields on account of the various injurious effects of crowding which have already been discussed. If it is impracticable to reduce the stand by hoeing or by use of the ordinary harrow it may be done by cross-disking with a disk harrow. The disk's should be so adjusted as to cut out the proper number of plants, which will depend, of course, upon their original thickness in the rows. THE RIGHT CROP TO LEAVE FOR SEED. Experiments at Stockton. Ivans., show clearly that at that place no crop later than the second will yield returns that will he at all satis- factory. Retarded growth during the dry part of the summer defers ripening until so late in the season that cold night- prevent the ma- turing of the seed. On the other hand, if the first spring growth is devoted to seed production the flowers are likely to become overmature before the best season for seed development arrives. Frequently also, largely on account of the variation in location of the zero point of growth" in the different individuals composing any strain, the first spring growth matures very unevenly. °Brand, Charles .T. Peruvian Alfalfa: A \f Agriculture, pp. S l I. L907. [Cir. 24] \i i \i I \ IN I ill IV \ I ED R0\* S FOB SEED. 19 For these reasons it is recommended, especially for the Great Plains and the cooler part- of the intermountain area, that the first growth of the second and subsequent year- be clipped so early that the time of seed setting will fall in midsummer or slightly later, when favorable conditions arc likely to obtain. The problem as to what crop should be left for seed under the vary- ing conditions of different areas has not yet been fully worked out. It may be well for seed growers to try by simple experiments along this line to get definite information on this point. One row may be given an early clipping and then left to go to seed; another a later clipping, while still another may be left for seed after the first crop has been cut for hay. and so on. The- temperature and moisture re- quirements \\ ill largely determine the best practice in this regard, but the necessary presence of suitable insects must not be overlooked. HARVESTING THE SEED CROP. The harvesting of alfalfa seed grown in cultivated rows does not differ materially from that in broadcasted fields. The accompanying illustration (fig. 3) shows a bunching device used by Mr. Lewi- Brott, of Sextorp, Cheyenne County. Nebr., for dropping the cut plant- in Pn m ■. g machine with dropper attachment In i I of alfalfa In cul- tivated rows in western Nebraska. The rows in this case arc one-half mile 1" windrow- without shattering the pods. The row- in this instance are 36 niches apart and weir seeded with a corn drill fitted with an onion seed plate set to drop at l' 1 inch interval-. With the row- 3 feet apart a mowing machine with a 6 fool cutter bar i- necessary if 24] 20 ALFALFA IN CULTIVATED BOWS loll SKIP. two rows are to be cut in each swath. This arrangement does away with the necessity of having an extra man to remove the newly cut bunches from the path of the mower at the next round. A mower with a 5- foot cut has been found to be too short to be satisfactory in cutting two rows at once. It is probable that a center-cut mower with one horse attached at each end of the cutter bar will prove better adapted than even the 6-foot side-draft machine. In planning to sow alfalfa for seed in cultivated rows the farmer should make his plans from the very beginning with a view to using to the best advantage the available machinery. In adapting the grain drill to secure the proper distance between rows, the mower with which the cutting is to be done must be kept in mind, as well as the cultivators that are to be used in controlling the weeds and keeping up the dust mulch. Thrashing may be done either from the field or from the stack. The latter method is probably the better, as curing in the stack seems to improve the quality of the seed. The haste necessary in order to keep the machines busy when thrashing is done from the field results in considerable waste. Whichever method is employed in handling the seed crop it is necessary that a tight-bottomed rack be used or there will be much loss of seed. Such a bottom can be secured by the use of matched flooring or by spreading canvas or a tarpaulin over the bottom of an ordinary open rack. Thrashing may be done in any one of three ways; the regular alfalfa huller, an ordinary grain separator supplied with a hulling attachment, or a grain separator fitted out with alfalfa sieves may be used. The last has been found to give very satisfactory results. Failure to appreciate the fact that the ordinary thrashing machine can be adapted to the thrashing of alfalfa has resulted in the loss of the seed crop on many fields in sections where seed production is not often attempted or, if attempted, is successful only in abnormal years or where it is carried on incidentally to other farming indus- tries. In using the ordinary thrasher it is recommended that the concaves be inverted in addition to inserting the special clover or alfalfa sieves. POSSIBILITIES OF SEED PRODUCTION IN CULTIVATED ROWS. Too much must not be expected from the method of growing alfalfa described in these pages. There are large areas in and around the regions to which this method is adapted where no amount of cultivation and isolation of the plants will bring success. On the other hand, there are thousands of acres now lying idle which with intelligent management will yield profitable crops. Maximum or [Cir. 24 j \[.l \l r\ IN ( I'l.l l\ Al in ROWS FOB SE] I'. 21 "bumper" crop-, must nut be expected under (lie prevailing con- ditions. The results obtained in the experiments thus far conducted with this method indicate that it gives especial promise in Utah, in east era Colorado, and in the western portions of Kan-as, Nebraska, and South Dakota. Yields of seed at the rate of ■> bushels to the acre have been obtained. The possibilities of the method when only in- dividual plants of large seeding capacity are used is indicated by the fact that plants removed 30 inches each way from other plants have given yields which if equaled by an acre of such plants at the same distance apart would rival the seed yield produced under the most favorable conditions in the present seed-growing sections. The method is a comparatively new one and should lie tested on it- own merits in each area or even in each community. Where rea- sonable doubt as to it- success under given condition- of rainfall. etc., exists, growers should at first devote only a small area, say 2 to 5 acre-, to row cultivation, increasing the size of the held if the results justify it. Seed production under the best conditions is somewhat uncertain. The certainty of profitable yield- of hay in most alfalfa-growing sections deters many farmers from letting their fields -land for seed. The light yield of hay procurable under ordinary conditions in the semiarid regions make- the growing of seed a more promising un- dertaking than in sections when' hay production is very profitable. It is probable that under very dry conditions the yield of hay in cultivated rows will also exceed that of a broadcasted stand. Com- plete data are not yet at hand, hut calculated yield- per acre based on the weight from a typical rod length of row are given in the accom- panying table: Tabu I. — Estimated yield of hay and seed t<> tin acre when «\u\U<\ \s grown in cultivated rows. Variety. weight of hay. Dry weight of hay. Weight of Beed. Pounds. I»r\ land at fulfil (Brott's) L) Turkestan alfalfa (S. P. I. No Lffi J . ill ruinate. 1,154 167 The yields of hay given in this table are from one cutting obtained on an upland field near Potter, Nebr., sixteen months after seeding. The mean annual rainfall at Kimball, the nearest point for which pre cipitation records are available, is about II inches, [n both L905 and 1906 this mean was exceeded considerably, but in L907 the total was 15 inches, while up to the end of September, L908, tl d showed [Cir.24] 22 ALFALFA IX CULTIVATED ROWS FOR SEED. 13.85 inches. Mr. Lewis Brott, on whose farm this experiment is under way, secured 150 bushels of seed from a thinly sown, broad- casted field of 50 acres in 190G. This yield was obtained from an old stand. DEVELOPING VALUABLE STRAINS FOR SEED PRODUCTION. Experiments under way at the Arlington Experimental Farm, near Washington, D. C, at Pullman, in the eastern part of the State of Washington, and elsewhere tend to prove that heavy-seeding propen- sity is heritable to a marked degree. In consequence of this, a race of unusual excellence could readily be secured by propagation of the progeny of individuals selected on this basis." When alfalfa is grown in rows to permit of intertillage, it is much easier to make selections than in broadcasted stands, chiefly hecause individuals in rows have better opportunity for expression of their normal character. In addition, the comparative isolation of the plants gives readier access to them. At first thought it might appear that in thinning out stands of row-cultivated alfalfa, only individuals of the greatesl seed-producing capacity should be left. A second thought quickly reveals the fallacy of this idea, as the ultimate purpose of all alfalfa growing is hay production. Selection based on seeding habits alone will develop this side of the plant unduly at the expense of its forage-producing capacity. The highest type of alfalfa for use in areas where seed production is the primary purpose in growing the crop is one that combines satisfactory hay and seed producing quality in symmetrical proportions. It is recommended that the selection of desirable plants commence as soon as the preliminaiy seeding has developed plants large enough to show their value. The field should be inspected row by row. and seed of the selected plants should lie gathered in advance of the regular harvest. The relatively small quantity of seed secured in this way should be sown with great care to make it cover the greatest possible area of ground. The plat of alfalfa thus secured will pro- duce seed of much greater value than that obtained from unselected plants. If this method is carried out. materially increased crops of seed may be secured without detracting from the hay value of the strain. Indeed, both the hay and the seed producing capacity may he increased by the process. Tf it i- impracticable to secure sufficient seed from selected plants for all of the new seedings that one desires to make, the selected seed a Some progress along this line lias already been made by Mr. P. K. Blinn and others. Mr. Blinn, who is in charge of the State substation at Rocky Ford. Co]p., has published the results of his investigations in Bulletins Nos. 121 and. 128 of the Colorado Agricultural Experiment station. [Cir. 24] ALFALFA IN CULTIVATED BOWS FOB S] 23 should be plained separately, and thai harvested from this plat should be used for subsequent seeding. This method will also afford an opportunity for demonstrating the relative value of selected as compared with unselected stock. CONCLUSION. The results obtained by farmers on a field scale, as well as of the experiments thus far conducted, indicate that the growing of alfalfa in cultivated row- for seed in the semiarid regions oiler- every promise of success. The method is recommended particularly for those sections where on account of the light rainfall but one crop, or at besl two crops, of alfalfa hay can be secured in each season. V\! to the problem of providing and maintaining a firm, moist bed, the controlling of the weed- oiler- the greatest difficulty. This i- especially true during the first season, when their rapid growth makes it difficult to control them by cultivation owing to the danger of covering the small alfalfa plant-. It i- expected that the machinery now in use in mosl communities can he adapted to i lie growing of -eed in rows. While the results indicate that the row method of culture will probably become an efficient factor in the development of the semiarid regions, too much must not lie expected of it. Those undertaking the work will be pioneers. I 'o them will fall the task of developing new devices and special adaptations of the implements at hand, upon which will de- pend in a large measure the practical success of the method. The alfalfa plant requires hut a -mall supply of moisture when seed setting i- going on. Heavy -eed crops are to a large extent dependent upon the prevalence during this time of a certain amount of dry weather and heat. In many part- of the semiarid regions an unusually favorable combination of these condition- i> present. The power to regulate by surface tillage the supply of -oil moisture makes the method of growing alfalfa in cultivated rows for -eed id' especial promise in those part- of the Great Plain-, intermountain area, and other sections where the average annual rainfall range- from 14 to 20 inches. Appro\ ed : .1 \ \m - Wilson, •■/// '//' . [i/rii ult in, . Washington, D. ( '.. January / . [CIr.24] O UNIVERSITY OF FLORIDA 3 1262 08928 9507