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 The person charging this material is responsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below.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 L16I O-I096 Eleven Years of Soybean Investigations Varieties Seeding Storage *. ^ r - '1 1 V- - . * * -. ' f. f+F. Bulletin 462 University of Illinois Agricultural Experiment Station CONTENTS PAGE PLAN OF VARIETY TRIALS 124 PERFORMANCE OF DIFFERENT VARIETIES 126 Northern Illinois 126 Central Illinois 130 Southwestern Illinois 137 Studies on Quality of Soybean Hay 137 SEEDING PRACTICES: EFFECTS ON YIELDS 141 Rate and Method of Seeding 142 Date of Seeding 146 EFFECTS OF STORAGE ON QUALITY OF SOYBEANS 149 Long Storage Reduced Stand and Yield 149 Shrinkage in Storage 152 Germination Tests of Stored Beans 155 Chemical Composition of Three- Year-Old Beans 159 SUMMARY AND RECOMMENDATIONS 163 APPENDIX: CHARACTERISTICS OF 66 VARIETIES AND STRAINS OF SOYBEANS.. . 166 The authors acknowledge the assistance of W. J. MORSE, J. L. CARTTER, and L. F. WIL- LIAMS, Bureau of Plant Industry, U. S. De- partment of Agriculture, particularly in the matter of identification and description of varieties. Urbana, Illinois January, 1940 Publications in the Bulletin series report the results of investigations made or sponsored by the Experiment Station Eleven Years of Soybean Investigations VARIETIES, SEEDING, STORAGE By W. L. BURLISON, C. A. VAN DOREN, and J. C. HACKLEMAN" OYBEANS have attracted more attention and have been more rapidly and more widely adopted than any other new crop ever introduced into Illinois. During ten years the Illinois acreage of soybeans harvested for grain expanded more than fivefold, from an average of 369,000 acres a year during 1924-1928 to an average of about 2 million acres during 1934-1938. b They have been grown far more extensively in Illinois than in any other state in the country, Illinois having since 1934 planted about half the total United States acreage of beans for threshing. The rapid development of soybean production in Illinois is not surprising when the reasons for it are considered. In the first place, soybeans are a remarkable crop, having a greater variety of uses than any other corn-belt crop, and they will thrive and yield well under a wide range of soil and seasonal conditions. Contributing further to their popularity have- been improvements in varieties and in production methods, in machinery for production and harvest, in manufacturing processes, marked expansion in the use of protein supplements in livestock feeding, and considerable expansion in industrial uses of soybean oil and meal. Also, farmers have gained experience in growing the crop. In the development of better production methods and higher yield- ing varieties better adapted for commercial grain production, the Illi- nois Station has long played an active part, investigations having started about forty years ago. The first publication one oh varieties was issued in 1897. Bulletin 310, "Growing Soybeans in Illinois," brought the data down to 1926. The present bulletin reports and analyzes data accumulated during the eleven years 1927 to 1937 inclusive. m W. L. Burlison, Chief in Crop Production ; C. A. Van Doren, formerly Assistant in Crop Production ; and J. C. Hackleman, Professor of Crops Extension. b The interest promises to increase still further, inasmuch as the Illinois soybean acreage in 1938 was higher than in 1937, and in 1939 was 24 percent higher than in 1938. Grove, E. W. Soybeans in the United States ; recent trends and present economic status. U. S. Dept. Agr. Tech. Bui. 619. 1938. 123 124 BULLETIN No. 462 [January, TABLE 1. ILLINOIS SOYBEAN PRODUCTION: ACREAGE AND YIELD, HAY AND BEANS, 1919-1937 (Acreages grown for soil improvement or forage, and acreages of soybeans mixed with other crops, are not included) Grown for hay Grown for beans Total acres in beans and hay Date Acres Total Average yield, acre-yield, hay hay Acres Total Average yield, acre-yield, seed seed 1919... (thou- sands) 12 (thousands of tons) 105 247 260 230 262 306 360 374 372 731 577 381 1 138 1 404 753 1 140 tons i.so 1.80 1.30 1.25 1.25 1.25 1.30 1.30 1.20 1.40 1.55 1.10 1.20 1.50 1.05 1.28 (thou- sands) 3 4 17 65 92 115 106 140 184 186 226 410 428 388 361 724 1 334 1 076 1 140 (thousands of bu.) 30 46 167 812 1 288 1 380 1 431 1 750 2 392 3 069 3 842 6 970 7 704 7 760 5 415 13 756 24 012 17 216 22 800 bu. 10.0 11.5 9.8 12.5 14.0 12.0 13.5 12.5 13.0 16.5 17 17 18 20 15 19 18 16 20 (thou- sands) 429 463 514 720 950 760 707 1 672 2 270 1 793 2 043 1920 12 1921..." 15 1922 70 1923 137 1924 200 1925 184 1926 210 1927 245 1928 277 1929 288 1930 310 1931 522 1932 372 1933 346 1934 948 1935 936 1936 717 1937 903 PLAN OF VARIETY TRIALS Fields. Varieties of soybeans have been tested on the DeKalb field in northern Illinois, at Urbana in central Illinois, and at Alhambra in southwestern Illinois for many years. As just stated, the results reported here are for 1927 to 1937 inclusive. Planting. In all the regular variety trials planting was done in rows 24 inches apart. The seed was inoculated each year until the crop had appeared on all fields in each rotation at least twice. Seeding was done, as a rule, as soon as corn planting was completed in the respective regions. It was done as uniformly as possible at the rate of 55 to 65 pounds an acre on a well-prepared seedbed. Selection of varieties. During the eleven years of tests reported here approximately* 65 varieties and strains were studied, not includ- ing many newer selections and the importations under preliminary trial at Urbana. Since the beginning of regular variety trials at this Station in 1906 some three hundred or more varieties and strains have been studied, tho many have proved of little value and are not reported The number is given only approximately because in extensive trials of this kind there is almost always some duplication of strains or varieties, and the duplication may not in all cases have been detected. 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 125 20 " I- f GROWN FOR HAY GROWN FOR BEANS TOTAL GROWN 1937 '35 '36 37 FIG. 1. SOYBEAN ACREAGE IN ILLINOIS, 1927-1937 Adaptability of soybeans to Illinois farming is evident in the marked increase in production during recent years. Total soybean acreage in 1937 was approximately five times that in 1927. Illinois has a much greater acreage of soybeans than any other state. either in this bulletin or in the preceding report, Bulletin 310. Varieties and types included in the trials have been obtained from the plant- breeding division of the Illinois Station, from other experiment stations, and from foreign countries. Varieties have been dropped from the tests if for any. reason they did not seem promising for Illinois. Extent of shattering, type of bean, market quality, and yield have been guiding factors in choosing varieties to be continued in the trials. Sometimes a variety that seemed promising has been replaced by a new variety having all the good qualities of the old and other desirable ones in addition, or by one having all the good features of the old in superior degree. Comparing yields. The annual yields of the different varieties and the "comparable" average yields of varieties grown for three or more years are given in Tables 2 to 13. The "comparable" averages rather than simple averages should be used as a basis for judging relative yielding capacity of the different varieties since the effects of seasonal 126 BULLETIN No. 462 [January, variations, introduced by some varieties having been grown for fewer years than others, are to some extent eliminated in the comparable averages. Comparable average yields were arrived at in the following man- ner: First the total yield of a given variety over the period of years during which it was grown was computed as a percentage of the total yield of the check variety over exactly the same period of years. This percentage is an index of the yield performance of the given variety. Next, the average yield of the check variety over the full eleven years of the trials was multiplied by the percentage rating of the given variety. The result is the comparable average yield per acre, of the given variety. Example: Total acre-yield of Manchu Selection (Table 2) during the four years 1934-1937=110.1 bu. Total acre-yield of check variety, Mandarin, during same four years, 1934-1937 = 88 bu. 110.1 -=-88 = 1.251, or 125.1 percent, the percentage rating of Manchu Selection. Average acre-yield of check variety, Mandarin, during eleven years = 21.8 bu. 125.1 percent of 21.8 bu. = 1.251 X 21.8 = 27 bu. per acre, the comparable average yield of Manchu Selection. PERFORMANCE OF DIFFERENT VARIETIES Northern Illinois The crop experiment field at DeKalb, where the soybean variety trials for northern Illinois were made, consists of dark loessial and drift soils of slight to medium acidity. It is not tile-drained but is sufficiently rolling to drain well naturally. Crop residues or manure and some rock phosphate have been applied to the soil, but no limestone has been used. One of the greatest difficulties in growing soybeans at DeKalb is that of frost damage, since the growing season is too short for many varieties. In the trials, therefore, effort has been made to find varieties that would mature early enough to escape the frost. Because of the frost problem soybeans did not appear regularly in the rotation on the DeKalb field until 1926. Grain production. Of the 15 varieties and strains tested for three or more years at DeKalb during the eleven years, 7 produced 25 or more bushels an acre (Table 2). Mandarin, a very early bean used as the standard for comparison in these northern Illinois tests and 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 127 SLaSil J=PE I 8*0 -3| >>& ovots**-* NfJOO -00 J, 3 8, .2 o^ot^tsoo 00 00 **5 P*3 :S :-- - :-- 4) 3 H x . l/)00l/>"500 r*5 c*5 f- ' 00 O es '^< ts cs -cs tf> rt " "* " i; J5 00 OvOOOO . (S -ooocs oooots eo -o> M (NW> S V O t-^ -^OO -ro Si : : : :% O^ *O O*O* -^"00 OOlO tSO "n 5 n o a : : : : : r^io' : :^ a^ --ot-: S vO c Ov 2 M.O 3 9,^0 ' -10 -X 1 5" g."oc |2-i CMCMCMCMCQ M*)N~*4 ariety was ' the total e of the E Agricultl J ~V >iT3 S ||:| i M i ! 1 ! id ' ' J> '. ' ' '< 2 P '< average y: obtained b imbers use U. S. Depi il H :^ V) *-* .<- 3SQ 3 C 3 g Co g-g 2 S g S _g . . . . g. . -OQ ^;j d ; ;^.s- w jgSg | : jljaq S2.2| SSSS S^Q^u 19 ^ ":S& jp*. 3 .:: ^a^gx cS B Ji S|S33 isjjl Igill ^ ^ ^ ^ ioUoKU Comparable itage rating was b The serial n Plant Industry, 8 -B 128 BULLETIN No. 462 [January, grown continuously at DeKalb for more than ten years, ranked eleventh, having a comparable average yield of 21.8 bushels an acre. Three selections of Manchu were among the highest yielding varieties. Black Eyebrow was a very satisfactory early bean, with a comparable average yield of 25.3 bushels an acre, but it is not suitable for com- mercial purposes. Mukden, Mandell, and Strain B are promising new beans. Funman likewise appeared promising, but it was dropped from the tests in 1939 because it is no longer being carried by seed dealers and consequently is not available to farmers. Hay production. Rather late-maturing varieties can be grown in northern Illinois for hay even tho, because of the short growing season, they are not suitable for grain production. Most of the varieties grown at DeKalb were early grain beans. The hay yields of most of the grain varieties were, however, higher than the hay yields of the two hay varieties that were used Chestnut and Wisconsin Black (Table 3). But these results should be considered only tentative since, with the exception of Illini, no variety was tested for more than two years. Illini averaged 2.5 tons of hay annually during the three years 1930, 1934, and 1935. Straw production. With the widespread use of combines there has developed considerable interest in soybean straw as a residue to be turned under ; moreover, some farmers still recognize soybean straw as a valuable roughage for livestock. Records were kept, therefore, of TABLE 3. DE KALB FIELD: HAY YIELDS OF 16 SOYBEAN VARIETIES, 1930, 1934-1935 Comparable . . . . Number average Percent Acre-yields Rank Variety of years grown yield per acre of check 1930 1934 1935 1 2 3 4 5 5 7 8 9 10 11 12 12 14 15 16 Manchu 1 tons 3.02 2.91 2.69 2.60 2.50 2.50 2.45 2.42 2.22 2.03 .98 .66 .66 .55 .38 .25 120.6 116.3 107.4 103.8 100.0 100.0 97.9 96.9 88.8 81.0 79.1 66.5 66.2 62.1 55.2 49.8 tons 2.75 2.28 2.28 i'.is 2.22 1.51 1.13 tons 2.61 2.65 2 '.22 2.23 1.63 2.31 1.06 1 '-'4 1.59 tons 2.99 2.76 2.81 2.57 2.S9 2.49 2.60 1.82 i!66 l'.2S Mandell 1 Dunfield 1 Mukden 2 Illini (check) .. 3 Wea 1 Funman 2 Manchu Sel. (Thomas) . . . 1 2 Manchu (Thomas) .... 2 Manchu (Wisconsin) . 2 Ito San 2 Chestnut 1 Mandarin 2 Wisconsin Black 2 Cayuga 1 See footnote a. Table 2. 1940\ ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 129 (2 5 g. s ; >'K^ > Li t, 00 -0 : :22 : SS- O O> \O 00 00 (SOD '2;~ H K ' '<& ' . 00 00 1^ to ^O OOtsOCK OOO 'X?^ uj **) ** ^ s .~ . oooor^. t>.t^m O O OOt^ o ^^ ;^ ; .10 -in s m Tf (} . -~ .0-, a ^ :^ : 00 -Q O -^ 00 O O -00 o -^ ;_; o, OOTlJ "> sg ^ .'I I (NIO .10 * a : ^ ooo -p c 5ts -5 .. ^ oo -o -o two years : : : : : : : :g : : W -00 ->O i one or a : : : *. r~ See foot -s ., ...... No data taken in 1935 iiyi "c" : : ^ : ,j s is- i* i l i a. Table 2. ' -^j. :cX : c c- : c 3 C'S 3 C'C 5^3 3 c ^3 * fl <5^|8 ^3-g o o rt g;-- rt 3 rt ^^Su.^ SSS 2< .Q <; -Q ,; Q : : : - Cw o- 3 to '_: S^D ">f !DS ... '!2CO ^^ J2 C i flJ ^J3 "^ v y3 o o*"? *. &S'CQ t- c cTj c S ^Cfl^jH^ **^- M 33U HSSacS SSSoQw See footnote 130 BULLETIN No. 462 [January, the yields of straw from the different varieties of soybeans grown in these tests. Of the varieties grown for grain at DeKalb for three years or more, Illini yielded the most straw (1.31 tons an acre, comparable average), followed by Black Eyebrow and Manchu (Table 4). Central Illinois Soybean variety trials for central Illinois have been conducted at the University farm at Urbana, on plots in the South-Central rotation, a four-year rotation of corn, corn, corn, and soybeans. The field consists of a dark-colored corn-belt soil. Rock phosphate was applied at the rate of a ton an acre every four years up to 1929, and a light application of limestone was made in 1903. On the plots that are operated under a grain system of farming, crop residues have been returned; while on a corresponding group of plots representing a livestock system, farm manure has been applied. Grain production. Of 26 varieties grown for three years or more at Urbana, 10 yielded more than the check (Manchu), and 15 had comparable averages of 30 bushels or more an acre (Table 5). Of the eleven leading varieties, Manchuria 13-177, Dunfield, Illini, and Manchu were among the popular types, and all four were grown for ten or more years. Tho yielding well during six years in the tests, the variety 04002-B USDA, has never become very popular because of the color of the seed and susceptibility to lodging. Hay production. In the South-Central rotation 25 varieties of soybeans that have been grown for three or more years have been cut for hay (Table 6). Ebony, grown at Urbana for thirty-three years, is used as a standard for these comparisons. All the varieties included are to a greater or less extent all-purpose beans, that is, beans almost equally well adapted for grain or for hay production. Thirteen of the 25 varieties had comparable average yields higher than Ebony, which yielded 2.54 tons of hay an acre for the eleven- year period. Of those thirteen varieties, Manchuria 13-177, Harbinsoy, Mansoy, Macoupin, and Dunfield deserve particular mention because they have given good yields of grain as well as of hay. Several of the varieties having high hay yields were also among the highest grain producers (Table 5). Straw production. The straw yields of 26 varieties are reported in Table 7. Manchu, used as the standard, produced an average yield of 1.18 tons of straw an acre. Thirteen varieties yielded better than 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 131 C X. l-g . . . 0voc * -o.o. in -o ts .0- - -10 **** Oir-iooo oo o *$ TJ ts rss ts 0> VOO S -CMfS -O -00 ts oo . .ss . "><*> < * 5 "> ^f -Tj>(NW5 ts -(Npg oo 00'* . i/j . . Oi -O "> 10 (S -iOiO OiOOfS (S -O CS oo -cso -S -CM P4 " WXNW5 -Oi moors (S -*> r- . -00 r^N^ ' r*5 . \O O O>Q -vooo ' 00 Tf . .*> . ^-r^ fsooo; m .(^^5 ro .csr- * -oo 0-0 -MO CNfS -N O> N5 -CS r<5 IO CN1/5 tstscscs i one or 1 o w>5 VO10 -00 .1*5 ... . . .(S) . . . .00 ies growi Wj . . . . ^i NcN ^i u ooooo cococococo COCOCOCOCO COCOCOCOCO o>a>oooot- CM CM CM CM CM CM CM CM CM CM CM . .** . < ;*7 ; ? :< ; : S 'Q ' :> igj : '< '.< '. "a ' Q -Q f ^mr-'-nJ CM" ,, O~. . : :Q 2 2 'S y . . ^ j o !o "O C njN C C o u 2 ^ rt rt o O **5 1 Mukden . . 2 Harbinsoy . .3 Ebony 4 Indiana 558 5 Mandarin. 6 Wilson-Five ;c/3 :cfl M R j| liSli lll j :*? rtf ? 1 l u ^& 2 (o fS O O O OO Tf ^ ^H oO S^5 a : '8 '* 00 oo o ^ CStNtStS -S - 00 -CSCS -**TjO -*f~001Ot~- 00 -WOO -00^ - CN - S3 . -<0-0 00*00-0, 00 fS r*5 ^ *> cs -MCS -cststs fscNcscsts -oo o 1O f*5 1O wo years oo g -"''" <*) (N CS CS one or t WJ so NOO csoo W 1OO> a i-JSS 00 -r- (N -t- -00 k s : : : : : : :^ : : : : :^ V _ _ _ _ OOOOO _ _ _ _ r S ot-t-r*o touu*u*u O*GN^Ov9> OOOOOOOOt*^ oooootooo .cnOT.no m-r^^co NO<=><=><=> " 4CaC4C4C4 CMCvJCMCMCa CQCMCJCQCvJ C4CMC4C4OI COVaeQCQN r* . ^ -^ : : :* : ; '% ' : - i ; : 1 ; ; ^ S& S J^ : S ; :^S ^.s -s ^S^z^ ^^n*? S a "^5 ^iS^ 02^- ^CG ci^ k> f *- o ^ rt aJ2 **> rt 3 ^^ ** rt O^g rt SscS<< SSQnS ; OjC/3 "5 > '"JD rtW c i J^23- -*|Jo feoc - ^ *^ . L>^?iotJ: ^- i ^ - i^ >2c/5 ^.^^.^ O^OOOvO -"{SfS^'lO ^ ' A o : n"e e -cj-'w .Z*- 1 *%3 S** S^ KOM3 -OOTj- O - - - _ . ._ . . .^ "^^ * Ti . . . -O -oooo ^ o> t^ oo t^ co oo oo i^* ^o . ^o -^ 0) 00 -ts -QCS . wo year -o -o S" -O O O O O i one or i : : : : : : : : : :g M . . -o -oo -o o -o Lies grow o -o -oo -oo \r> -ro -cs -0000 u 1 lOr*5W5t- lOfStSCS^n ^tfO^QOO CCoor^Oio fO*^(Ncs>OO exouicoot i-coeMMea -~ 2 =o^ ..-.^jo nSSSSS ' 1 ! !t~ '.'.'.'.' :< :15^ : : : : : : : : ^ yiy iiiil ;J5 ; 2 , .^5 :^i Q : : : : : '.% u K O "O ! tS"*S'Wj<'O li^l^ S|8H| ^=1=^S fSbfl U ^O "S^c^C S C WI w'^'SSfco 134 BULLETIN No. 462 [January, Manchu, the five highest being Macoupin, Morse Selection 230, Type 117, Morse, and Manchuria 13-177; Three others (Scioto, Harbinsoy, and Mansoy) which have been generally grown on Illinois farms with satisfaction, were also among the higher producers of straw. Yields on other areas at Urbana. Yields of soybeans grown on four other series of plots at the University farm are reported in Tables 8, 9, and 10. Fifteen or more varieties were grown for three or more years in each location. As the plots varied in fertility, a summarized comparison of the annual yields cannot be made, and the results are therefore presented only as separate annual records. Among the better yielding beans were Illini, 04002-B USDA, Manchu, Dunfield, and Manchuria 13-177. These are about the same varieties as those that led in yields on the South-Central rotation. TABLE 8. URBANA FIELD, MISCELLANEOUS PLOTS: HAY YIELDS OF 21 SOYBEAN VARIETIES, 1929-1935 Variety Number of Northwest rotation" South- west ro- tation, 11 1931 Mumford plots North- Central rota- tion, d 1935 years grown 1929 1930 1932 1933 1934 Mansoy 6 tons 3.22 3.12 2. SO 2.64 2.56 3.10 3.36 3.02 2.96 2.82 2.30 2.80 2.26 2.56 tons 4.31 3.82 3.93 3.61 3.92 3.56 3.87 3.79 3.65 3.23 3.02 2.85 3.30 3.53 tons 3.43 3.45 3.51 3.34 3.09 3.72 3.37 3.37 3.56 2.93 2.86 3.51 3.79 3.34 3.34 2.62 tons 3.00 3.57 3.35 2.94 3.27 2.76 3.06 2.97 2.98 3.41 3.28 2.80 2.57 2.47 2.85 3.19 tons 3.51 3i48 3.51 3.27 2.95 3.23 2.89 3.37 2.98 3.01 3.18 2.94 3.15 3.76 tons 3.93 2.37 2.99 3.19 2.59 3.23 2.74 2.47 2.36 2.91 2.65 3.18 2.46 1.84 tons 3.63 3.19 3.57 3.76 3.45 i!95 3.63 3.52 3.51 3.19 Dunfield 6 Manchuria 13-177 4 4 Manchu 6 Peking 7 Harbinsoy 7 7 Manchu (Perry King) .... 5 54610-3 USDA* , . . 5 04002-B USDA* 6 Ilsoy 7 Wilson-Five 7 Virginia , 7 Ebony 7 Illini 7 Varieties grown one or two years only Aksarben 2 2.74 4.06 Morse 2 2.62 3.59 A.K. 146 1 1.87 Midunk 2 2.66 2.31 2 3.00 1.97 Northwest rotation consisted of corn, soybeans, potatoes, and alfalfa, the alfalfa remaining on the same field while the other three crops completed two cycles. b Southwest rotation consisted of corn, oats, ctover, and wheat. Soybeans appeared in the rotation when clover failed. No definite rotation was in use on the Mumford plots during these years. d North-Central rotation consisted of corn, corn, spring grains, and clover, with soybeans when the clover failed. "The serial numbers used are those of the Division of Plant Exploration and Introduction (formerly known as Division of Foreign Plant Introduction), Bureau of Plant Industry, U. S. Department of Agriculture. ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 135 111 I?" "> -CN -(NCSfSCS Ji olt^di * <3< <^vO OOOO'* 00 00 f) ^^ O CS f) ^^ O CS O f -rr> n fO (*5 <5 c OOOO 000 . oo '(S~H 5 :<^ f5 ro f*5 -H n (^ -00 O tsts?3 -< ss OMN --H i/>>O -0 OOOO -\O ClOvOOt- tSCSCSr*>~*- -m \r> s 1 1 1 z s <*5 u -* -00 OilO NfO U1^00(SNOO Is TJIO< -o oovoooo ooooaoooo 9. -fOW5 a ->/>oo 1 co" Id HH g 1 "3, B WJ tO ^ J^(O '^Ht^ -T*O> S tSOvOO-H OOOO>W -WO -^00 t^Ov - OA > * i M >H Mumfo M fO S^'^-.'^ '^^'' '.'"'.'' c, lOOulO'i 1 ift^Of^ N--OOOWO c "O^f^t^io r-Jcs^cNts tststs-H^ 8 f/5 55 1 a_ I 5 * u, O ---- inifl -1/500 O Ov 8 CS ^. _ r^ T)< N HN OO^O.O*00 a g H >H < K i o M O n V, t^OOf^CSt^ IO -1/500 (NOO^CSt^O -nfJOO'-i O -OO O*O>OOOOOOv o years only cs o es o\ H C^ io i < n one or tw o -J cs * O'C'C'Oio 10 -10^ ts <* ^ TJ> \n ^H o : : : : : 8 : : : : .LLANEOUS rthwest rota oo (N co 00- -W5 -\O (* tM -N Varieties gt 5 cn KH s Q* d Z o> r ts S : : : : : _;:::: j : :^ :^ to -O -O -O OOOO -O a -t- . _ . - -in ^in^cs -fs ooooo -o 00 00 1/5 O *1* **> 10. URBANA FI] Number = n > fc| ^& t^OOuliOOO r- -T ~ X r~ 00 00 00 00 >O O -irs^*-"- ts^^tscs Table 8. | t M ; ;a 1 i ; :R : ; i i I ij ti ; ;3 ; : ;g footnotes, 1 ^ ;4^ 1 gb.5-?>, &llil 5 ll 1 ? Bfisl SS^gs =^-ac-5 5-^rt^oS c8rtcd~rt 23O._ ffi^SSw SSS^K Ss>QS5 rt' i^ If id g*li^ SISI3 13111 1 1940} ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 137 Southwestern Illinois The Alhambra field, where the variety tests for southern Illinois have been made, consists of dark loessial soil of medium to strong acidity. Only one soil type has been mapped on the field; namely, brown-gray silt loam on tight clay (Putnam silt loam). The land is practically level, the west half being tile-drained and the east half surface-drained. Because of the impervious nature of the subsoil, drainage is not satisfactory. A rotation of corn, oats, soybeans, and wheat with a seeding of sweet clover as green manure has been practiced on this field. No animal manure has been applied. To the plots in the tests reported here limestone and rock phosphate have been applied. Grain production. Of 16 varieties grown at Alhambra for three years or more, five had higher comparable yields than Illini, the check, which gave an average of 22.2 bushels an acre (Table 11). Six varieties (Morse Selection 230, Scioto, Mansoy, Macoupin, Manchuria 13-177, and Illini) deserve special note. This selection of Morse, how- ever, will probably never become widely popular, because of the color of the dry bean, which is green. Type 119 also should be mentioned as a very promising bean, tho data on it are given for only one year, 1937. In that year it yielded higher than any other variety in the test, and in 1938 and 1939, not reported here, it also did outstandingly well. Hay production. Soybeans were harvested for hay at Alhambra only three of the eleven years of these tests. The results, reported in Table 12, should therefore be considered merely tentative. Nine of the eleven varieties grown all three years yielded more hay than Illini, which produced 2.07 tons an acre. Of the highest ranking varieties (Macoupin, Mansoy, Manchuria 13-177, Peking, and Virginia) only Peking and Virginia are strictly hay beans; the others are primarily grain beans, tho they are suitable also for hay production. Straw production. Yields of straw from 15 varieties of soybeans grown for three or more years at Alhambra are listed in Table 13. Illini, averaging a little less than a ton of straw a year, produced less straw than any other variety. The five that produced the most straw were Ebony, Peking, Scioto, Virginia, and Ilsoy. Studies on Quality of Soybean Hay In order to determine the percentage of leaves, stems, and pods in different varieties of soybeans, samples of the varieties grown on two rotations at Urbana during 1931-1934 were separated into the various 138 BULLETIN No. 462 [January, e ^ |-s . VOK>^ * -(S.OOCS oo ooioOMO't (N \O (N O\ IO CSCSeSCS(S -{NfMtN OOOOO^OO ts x)ts rocscscMo) cs cscs 1^ -1O -^" * -O s ' ' .j '-.:' . . . .0. ties gro .^^ .^ -(N -CS 1 to mature I 1 6, Table 2 . . .^ . . . . '. o . . '.' '.'..'.'. r* . . .** 2" . . . . :<:::: B * ' I : 8% I : : l i ; : : Kites (J ail( "5 : '*'* 1 : ^ : : u5 ; xo.3 -g :2oics gs 1 rss||: ^Qcuc c^Cl-bC o.Sartrt .-OgS" SwSSS 5SQXi> -S *> si Illlll ill 111 llli HI j 1 1 * 19401 ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 139 TABLE 12. ALHAMBRA FIELD: HAY YIELDS OF 17 SOYBEAN VARIETIES, 1933-1935 Comparable Number average Percent Acre-yields Rank Variety of years grown yield per acre ol check 1933 1934 1935 tons tons tons tons 1 Macoupin 3 2 .74 132, 2 3, .43 2. 41 2.38 2 Mansoy , , 3 2 .68 129. 4 3 .07 2, 85 2.13 3 Manchuria 13-177... 3 2 .66 128 3 3 .17 2 .42 2.39 4 Peking 3 2 .60 125 6 3 .04 2 .56 2.21 5 Virginia 3 2 .55 123, 3 3 .03 2 ,46 2.18 6 Ebony ... 3 2 .54 122. 7 2 ,49 2 ,32 2.82 7 Wilson-Five 3 2 .49 120 ,4 .4 .08 2 .49 1.92 8 Kingwa 3 2 .29 110 8 2 .90 1 .90 2.09 9 Dunfield 3 2 .11 102 1 2 .15 2 .26 1.94 10 Illini (check) 3 2 .07 100, 2 .43 2 09 1.70 11 Ilsoy 3 1 .67 80. 9 1 .66 1 .90 1.47 Varieties grown one or two years only Morse 2 3 .42 2 .53 Norredo 1 2.11 54563-3 USDAb 1 2.10 Harbinsoy 2 2 .17 2.45 Morse Sel. 230 1 2.01 Scioto 1 1.94 b See footnotes a and 6, Table 2. parts and weighed. A total of 115 separations were made on 16 differ- ent varieties during the four-year period. Each plot was sampled by removing all plants in areas containing 33 square feet each in six well- distributed locations. Each variety was sampled when it was in the best condition for making good-quality hay, which was before the leaves began to drop but after most of the beans in the pods were well filled. A composite sample of approximately 10 pounds was separated into leaves, stems, and pods. Each fraction was dried in an oven. The varieties differed appreciably in percentages of leaves, stems, and pods (Table 14), but the differences recorded here should not be taken as conclusive evidence of true varietal differences, for the num- ber of samples from each variety was not large enough to assure that it was entirely representative. There were, however, enough total separations to give a fairly accurate idea of the proportions of leaves, stems, and pods in soybean hay in general. As an average of all the varieties sampled, approxi- mately one-third of the hay was leaves, another third was stems, and the other third was pods, on the basis of oven-dry weights. The hay varieties as a group (Ilsoy, Virginia, Wilson-Five, Peking, Ebony, and Kingwa) averaged slightly fewer leaves, but slightly more stems and pods than the grain varieties. There is thus no basis, in these 140 BULLETIN No. 462 [January, P 3* HJ 8 SB$g a: S OJS3 :? j g :2S PO r~ <*) 00 Pi 5 ^ -Nt-f5 -.10^ -- ^-H^,ro oo -t^... -...-,._ \r> n ^0 -* ^,00^ . -H * -H0004 IO ^H ro 00 Ot 2 * M 5 -T^,H"^ ' * ^H*^^H" '. ^ Ov 00 00 *O ID m HS o : ; ^ J*^3CS -CSf^ ^ < -r^l/^Ov - .Tf.t- tN "5 *VOVOOOO ^ "5 5 :^ :^ : j :^;^;^; Ov^Ot-a- -^o - -oo -oo O o o\ C4 o i, -O -OO -OO s -PO ** 04-< ooooo wo years Ov 00 o ... 10 -ro NO -OO oo *<) wj - t^-o i one or "^ 0* o c^ f*} o O O Lies growl o 00 100-1-0 * 1 rt 1 ; : ; . '. '.o '.'.'. j^:::: : : : : 1? : :<; : : E? :<^ . *o . .N . : : :"v.B : _-^-2 i- o _c o a o cs lllll ill! III! 111III 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 141 TABLE 14. SOYBEAN HAY: LEAVES, STEMS, AND PODS IN GRAIN-TYPE AND HAY-TYPE SOYBEAN VARIETIES SAMPLED BEFORE HARVEST, URBANA, 1931-1935 (Weights are given in pounds per acre on an oven-dry basis) Percent each part was of Variety Type* Leaves Stems Pods Total total weight Leaves Stems Pods Ib. Ib. Ib. Ib. Harbinsoy . . Grain 2 148 2 182 1 663 3 993 36 36 28 Macoupin Grain 2 324 2 354 1 919 6 597 35 36 29 Mansoy Grain 2 613 2 255 1 962 6 830 38 33 29 Manchu . . Grain 2 392 I 824 1 803 6 019 40 30 30 Dunfield Grain 2 420 1 784 2 058 6 262 39 28 33 Manchuria 13-177 . . Grain 2 605 1 935 2 487 7 027 37 28 35 Ilsoy .. Hay 1 837 1 836 2 190 5 863 32 31 37 Virginia .. Hay 2 075 2 123 1 523 5 721 36 37 27 Wilson-Five .. Hay 1 714 2 211 2 171 6 096 28 36 36 Peking .. Hay 1 996 2 044 2 365 6 405 31 32 37 Ebony Hay 2 245 2 Oil 1 868 6 124 37 33 30 Kingwa .. Hay 2 097 1 886 2 061 t> 044 35 31 34 Illini . . Grain 2 024 1 628 2 171 5 823 35 28 37 54610-3 USDAb Grain 2 322 1 685 2 174 6 181 38 27 35 Manchu (Perry King) Grain 2 153 1 830 1 948 5 931 36 31 33 04002-B USDAb . . Grain 2 112 1 504 1 685 5 301 40 28 32 Average Hay varieties 1 994 2 019 2 030 6 043 33 33 34 Grain varieties 2 312 1 898 1 987 <> 197 37 31 32 All varieties 2 192 1 943 2 003 6 138 36 32 32 Varieties listed as "grain" type are those having seed suitable for commercial purposes. Many of these varieties are suitable also for hay. Varieties listed as "hay" type do not ordinarily have grain suitable for commercial purposes. b The serial numbers used are those of the Division of Plant Exploration and Introduction (for- merly known as Division of Foreign Plant Introduction), Bureau of Plant Industry, U. S. Department of Agriculture. data, for any recommendation to farmers to change their present practice of using so-called grain-type beans for the production of hay. Samples of the field-cured hay also were taken from the varieties grown on two rotations in 1931 and on one rotation in 1932, 1933, and 1934. Seventy-eight samples were collected, and the weights of leaves, stems, and pods were compared with the weights obtained by sampling plots before they were cut for hay. Approximately 74 per- cent of the leaves, 77 percent of the stems, and 89 percent of the pods (by dry weight) were retained by the soybean plants during the field-curing process (Table 15). SEEDING PRACTICES: EFFECTS ON YIELDS The best method, rate, and time of seeding soybeans in order to obtain maximum yields of grain was a matter on which opinions and practices differed widely during the years when soybeans were becom- ing established as a farm crop in Illinois. Tests to determine the relative merits of the different practices were therefore begun at Urbana in 1926 and continued thru 1932. 142 BULLETIN No. 462 [January, TABLE 15. SOYBEAN HAY: LEAVES, STEMS, AND PODS RETAINED IN FlELD-CURED HAY, URBANA, 1931-1934 (Weights are given in pounds per acre on oven-dry basis) Leaves Stems Rotation and year Before harvesting In field- cured hay Before harvesting In field- cured hay Southwest, 1931 Ib. 2 234 Ib. 1 606 1 436 1 797 1 905 1 857 1 720 Ib. 1 748 1 405 2 029 2 870 2 473 2 105 Ib. 1 573 1 381 1 829 1 971 1 316 1 614 South-Central, 1931 1 931 1932 2 250 1933 2 773 1934 2 430 Average 2 324 Pods Percentage of parts retained Rotation and year Before In field- harvesting cured hay Leaves Stems Pods Southwest, 1931 Ib. 1 674 Ib. 1 670 71 9 90 99 8 South-Central, 1931 1 404 1 498 74.4 98.3 106.7 1932 ... 1 951 1 997 79 9 90 1 102 4 1933 2 070 1 425 68 7 68 7 68 9 1934 1 846 1 412 76 4 53 2 76.5 Average .... 1 789 1 601 74 01 76 67 89 49 Rate and Method of Seeding In an effort to determine the most desirable rate for seeding soy- beans and the best method of planting them, comparisons were made with different amounts of Illini beans planted in rows 24 inches and 8 inches apart (grain-drill width). Beans seeded with a grain drill in 8-inch rows are usually said to be "drilled solid," as distinguished from those drilled in rows far enough apart to retain the row appear- ance thruout the growing period. Where the beans were drilled solid, the rates of seeding ranged from 48 to 282 pounds an acre. In rows 24 inches apart the rates ranged from 32 to 147 pounds an acre. The soybeans drilled solid were cultivated with a rotary hoe two or three times during the early part of the growing season; those in 24-inch rows were cultivated three times with a rotary hoe and two or three times with a duck- foot cultivator. Each rate of seeding for each distance of planting was made in duplicate. Row seeding gave best yields. Acre-yields of grain were higher where the beans were seeded in rows 24 inches apart than where they were drilled solid. Average yields from plots drilled solid at the various rates of seeding were all below the average yields from plots drilled in 24-inch rows at the same rates (Table 16 and Fig. 2). In two years, 1929 and 1932, each plot seeded in 24-inch rows yielded 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 143 TABLE 16. RATE AND METHOD OF SEEDING: EFFECT ON YIELD OF SOY- BEAN GRAIN, ILLINI VARIETY, URBANA, 1928-1932 Range in rates of seeding per acre* 1928 1929 1930 1931 1932 Five- year average yield Exact rate Yield Exact rate Yield Exact rate Yield Exact rate Yield Exact rate Yield 24-inch rows (bean drill) More than HOlb. . . Ib. bu. 147.4 30.9 Ib. bu. Ib. bu. Ib. bu. Ib. bu. bu. Average 126.6 30.0 30.5 126. i 46.1 46.1 111.1 21.3 21.3 114 25.9 25.9 122 31.0 31.0 31.6 70-110 pounds 89.7 31.6 79.5 32.6 90.4 42.5 80.0 45.3 79!i 23\6 70.6 19.9 79 26A 100 35.0 80 36.5 Average 50-70 pounds 32 . 1 68.9 33.8 43.9 68.2 46.5 21.8 26.4 68 28.0 35.8 32.0 Average 53.8 32.3 33.1 56.9 46.3 46.4 59.3 20.5 20.5 .. 2S.O 58 35.4 35.4 32.7 30-50 pounds 45.7 45.6 46.1 20.5 44 31.1 44 37.3 38 8 25 8 33.9 18.0 32 31.8 32 37.4 Average 25.8 45.6 19.3 31.5 37.4 31.9 8-inch rows (grain drill) More than 2 10 Ib.. . 243.5 30.3 285.7 41.0 282.4 14.3 Average 170-210 pounds.. . . Average 230.4 29.3 29.8 196.9 29.7 239.5 39.4 40.2 192.0 38.1 230.2 15.3 14.8 192.0 16.8 223 24.8 24.8 227 24.6 24.6 180 25.2 26'.B 27.5 130-170 pounds.. . . 169.4 17.9 154 26.0 Average 146.0 28.5 28.5 143.1 38.1 38.1 144.0 17.3 17.6 1138 26.1 26.1 143 25 . 2 25.2 27. i 90-130 pounds 121.4 18.4 111 27.4 121 26.2 95 29.4 96.0 38 99.8 19.3 Average 50-90 pounds. . . . 29.4 38.0 18.9 27.4 48 24.7 26.2 88 27.9 28.0 51 27.8 Average. . . 24.7 27.9 26.3 The rates used are grouped in wide ranges so that the averages will reveal differences despite seasonal influences on yields. more grain than the highest yielding plot drilled solid. In the three remaining years (1928, 1930, and 1931) 13 of the 18 plots seeded in 24-inch rows produced more grain than the highest yielding plot drilled solid. Likewise, in tests made in 1930, Illini soybean plants seeded in rows 24 inches apart had a larger number of pods per plant and matured earlier than the plants drilled solid (Table 17 and Fig. 3). Those seeded in 24-inch rows at the rate of 1 bushel an acre produced an average of 20 pods per plant, 8 percent of which were immature on September 23 ; whereas those drilled solid at the rate of 2 bushels an acre produced an average of 8 pods per plant, with 48 percent immature. Rates of 1 bushel an acre for soybeans in 24-inch rows and 144 BULLETIN No. 462 [January, 2 bushels an acre for those drilled solid are very frequently used by Illinois farmers. Where the rates of Illini seeding in 1930 were practically equal (1.9 bushels an acre in 24-inch rows and 2.0 bushels in 8-inch rows), the plants in the 24-inch rows averaged 16 pods per plant, 12 percent of which were immature on September 23 ; whereas those drilled solid had 8 pods per plant, 48 percent of which were immature. Plants pro- duced from beans drilled solid at the extremely high rate of 4.7 bushels 170-210' 130-170 L 90-130 50-90* jZJ>*ji>J%%^^ /// / %tf%^ YIELDS PER ACRE 24' ROWS 777* 8" ROWS Four-year average, 1928-1930, and 1932. 'Two-year average, 1931 and 1932. FIG. 2. YIELDS OF SOYBEANS PLANTED AT VARIOUS RATES IN Rows 24 INCHES APART AND IN Rows 8 INCHES APART, 1928-1932 From the standpoint of yields obtained, no important advantage was held by any one rate of seeding over the other rates. Seedings in rows 24 inches apart consistently yielded more than those drilled solid. TABLE 17. RATE AND METHOD OF SEEDING: EFFECT ON NUMBER OF PODS PER PLANT AND MATURITY OF SOYBEANS, ILLINI VARIETY, URBANA, 1930 Method of seeding Rate of seeding per acre Number of plants in 10 sq. ft. Number of pods per plant Percent immature pods b Yield per acre 24-inch rows (bean drill) Ib. 33.9 13 28 12 bu. 18.0 59.3 111.1 . . 121 4 21 27 56 20 16 8 8 12 48 20.5 21.3 18.4 282.4 122 4 75 14.3 Average of four well -distributed counts. b Pods which, on September 23, were still green in color were classed as immature. 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 145 FIG. 3. GROWTH OF SOYBEANS AS INFLUENCED BY METHOD AND RATE OF SEEDING Strikingly fewer numbers of pods per plant were produced where the seeding rates were heavy, tho the increased number of plants resulting from heavy rates of seeding tended to maintain acre-yields. Seedings of 1 bushel per acre in rows wide enough apart to be cultivated and of 2 bushels when drilled solid are common in Illinois. an acre averaged only 4 pods per plant, of which 75 percent were immature on September 23. Plants from beans seeded in 24-inch rows at the lowest seeding rate (.5 bushel an acre) averaged 28 pods per plant, and of these 12 percent were immature. Yield not only consideration. Altho in these tests a higher yield of grain was obtained by planting the beans in rows, this fact does not necessarily justify row planting. Relative growing costs, competition with other crops (mainly corn) for labor and equipment, and relative control of weeds must also be taken into consideration. Growing costs are usually higher when the beans are planted in rows far enough apart to be cultivated, for two or three cultivations with a row cultivator are usually required in addition to the cultiva- tions with a rotary hoe that are usually given to beans planted by either method. Moreover the cultivations are likely to compete with 146 BULLETIN No. 462 [January, corn for labor and equipment, because they usually come at the time when corn needs to be cultivated. On the other hand, planting beans in wider rows so they can be cultivated with a row cultivator gives better control of weeds than is possible when the beans are drilled solid with a grain drill. For weed control in soybeans drilled solid farmers usually depend on two or three cultivations with a rotary hoe while the plants are young and the shading out of the weeds after the plants have grown large enough to cover the ground. Some farmers not already faced with a serious weed problem have been able to control weeds in beans drilled solid. Nevertheless in many localities failure to control weeds in beans is causing the weed menace to become increasingly acute. No optimum rate of seeding determined. Increasing or decreas- ing the rate of seeding did not consistently affect the grain yield of the Illini soybeans grown in these tests (Table 16 and Fig. 2). Of the soybeans drilled solid, those seeded at 90 to 130 pounds an acre gave the highest average yield for the five years of the test, altho the yearly results varied considerably. In 1928 and 1929, for example, the seedings that were made at more than 210 pounds an acre gave the highest yields, while in 1932 the 50-90-pound seedings gave the high- est yields. When the beans were planted in 24-inch rows, 50 to 70 pounds an acre gave the highest average yield, tho again there was much variation from year to year. In 1930 the highest yields were obtained from seedings within the 70-110-pound range, and in 1931 and 1932 from seedings within the 30-50-pound range. In view of such similar grain yields from different rates in the same year, and the wide year-to-year variations in yields from seed- ings at the same rate, it is evident that farmers cannot have much confidence that increasing the rate of seeding above a moderate rate (about 1 bushel an acre for beans drilled in 24-inch rows and l}/2 bushels drilled solid) will increase the yield of grain. Nevertheless, except when seed is high-priced, there is some justification for planting at rates a little higher than these, because of the greater likelihood of obtaining a good stand under adverse conditions. Particularly where beans are drilled solid, a heavy stand is desirable as an aid in weed control. Date of Seeding In an effort to discover the best time to seed soybeans, plantings were made over a period of six years at six 10-day intervals, beginning May 1 each year and extending to June 20. Twelve varieties, at least ten each year, were seeded in rod rows replicated four times. 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 147 TABLE 18. DATE OF SEEDING: AVERAGE YIELDS OF 12 VARIETIES OF SOYBEANS SEEDED AT DIFFERENT DATES, URBANA, 1926-1931 (Bushels per acre) Date of seeding 1926 1927 1928 1929 1930 1931 Average May 1 22 20 19 12 12, 15 .0 .4 ,7 ,9 5 ,0 29.8 34.7 37.2 33.8 31.8 23.2 13.9 15.1 14.7 14.6 13.9 12.7 27.2 25.0 24.9 26.4 25.6 20.4 23.2 23.4 23.7 21.8 21.0 17.9 May 10 .. 23 .1 ,9 ,7 , .5 22 22, 22, 24. 23 ,3 5 ,6 5 ,5 May 20 22 June 1 20 June 10 17 June 20 .. 12 In general the early seedings of soybeans yielded more grain than the later seedings, the yields of each of the May seedings averaging higher during the six years than those of either the June 1 or June 10 seedings by approximately 2 bushels an acre, and higher than those of the June 20 seedings by about 6 bushels an acre (Table 18 and Fig. 4). During five of the six years the highest yields were obtained from May seedings. There was no marked difference in the average yields obtained from the May 1, May 10, and May 20 seedings. Of 67 comparisons involving the twelve varieties over a period of 'six years, the May 1 seeding yielded highest 19 times; May 10, 14 times; May 20, 14 times; June 1, 7 times; June 10, 8 times; and June 20, 3 times (Table 19). In one of the 67 comparisons the yields ob- tained from the May 1 and the June 1 seedings tied for highest rank, and in another the May 10 and May 20 seedings tied for highest. May seedings returned the higher yield in 72 percent of the trials. MAY 1 MAY 10 JUNE 20 (6 YEARS 1926-1931) FIG. 4. AVERAGE ACRE- YIELDS OF SOYBEANS PLANTED AT DIFFERENT DATES Tho the May seedings averaged higher yields than the June seedings, no great decrease occurred until the June 20 seeding date. The results shown here are averages of twelve varieties. 148 BULLETIN No. 462 [January, TABLE 19. DATE OF SEEDING: YEAR-BY-YEAR YIELDS OF 12 VARIETIES OF SOYBEANS SEEDED AT DIFFERENT DATES, URBANA, 1926-1931 (Bushels per acre) Variety and date seeded 1 1926 1927 1928 1929 1930 1931 Average Manchu May 1 38 .1 42.2 17, ,0 37.9 33.80 May 10 18. 25, 35 ,7 44.3 16 ,9 33.9 28.97 May 20 16. 5 23. 6 31. 6 49.5 16. 9 36.9 29.17 June 1 IS. 1 24. 4 22, 3 44.0 14. ,1 37.3 26.20 June 10 16 .5 26 ,9 26 ,0 46.8 13. 4 36.0 27.60 June 20 14. 6 29. 7 14 33.6 13, 7 28.6 22.37 Wilson-Five May 1 33.0 11 .9 21.7 22.20 May 10 30.9 14 .1 20.3 21.77 May 20 27.9 12 .8 22.9 21.20 June 1 31.0 12 .3 19.2 20.83 June 10 26.1 14 ,5 20.8 20.47 June 20 12 .2 18.2 15.20 Columbia May 1 21 .8 9.4 19 ,0 25.1 18.83 May 10 . 27, 24 5 19 ,7 23.6 16 ,6 27.8 23.20 May 20 26. 19 ,8 15 ,6 38.0 17. ,2 27.0 23.93 June 1 23. 7 20. 7 8, ,1 26.8 16. 7 32.4 21.40 June 10 18. 9 16. 5 9 12 ,9 31.4 17.02 June 20 16. 1 10 ,7 23.1 16.63 Chestnut May 1 25 .3 38.7 9 ,8 24.4 24.55 May 10 17. 9 13. 7 24, ,7 41.9 13, ,9 22.4 22.42 May 20 16. 1 15. 1 25. 2 30.8 15. 3 20.9 20.57 June 1 18. 19. 4 21 ,7 37.1 15, .8 22.5 22.42 June 10 11. 8 22. 2 19. 6 28.7 13. 8 19.6 19.28 June 20 9. 5 19, 8 14 :9 25.0 11 8 13.2 15.70 Guelph May 1 19 6 18.3 6.9 23.1 16.98 May 10 16. 1 22, 2 19 ,2 17.4 9. 18.7 17.10 May 20 16. 1 28, ,3 18 .2 25.1 9 6 18.9 19.37 June 1 18. 4 22. 6 10 ,3 26.1 10 9 18.2 17.75 June 10 11. 3 20. 3 11. 7 26.4 9. 4 16.7 15.97 June 20 8. 1 25. 19.9 11. 1 15.2 15.86 Virginia May 1 26 .7 38.1 14 .3 27.5 26.65 May 10 26. 32 ,6 27 ,1 50.4 15 .8 24.9 29.47 May 20 27. 4 32. 26. ,7 51.2 14 25.1 29.40 June 1 21. 8 35 4 43.9 15, ,5 27.5 28.82 June 10 21. 3 32. is, 4 38.3 17, 7 24.3 24.83 June 20 12. ,8 24, ,5 16 ,4 19.8 18.38 Hurrelbrink May 1 14 ,4 32.5 15 .3 31.1 23.33 May 10 12 ,7 30.5 14. ,1 25.3 20.65 May 20 10 ,6 37.4 13, ,6 20.4 20.50 June 1 4, ,7 36.3 14, ,2 16.8 18.00 June 10 .S 1 13 .3 20.0 12.80 June 20 11, 9 17.9 14.90 Wisconsin Black May 1 15 .9 22.3 13 .7 19.5 17.85 May 10 6 ,2 9 .9 16 .3 34.5 16 .9 18.5 17.05 May 20 8. ,5 11 ,8 22 ,7 35.9 14 .9 22.3 19.35 June 1 10 10 .4 16 .7 34.7 16 .1 23.3 18.53 June 10 14, ,7 18 ,4 20 .1 30.9 15 .3 26.4 20.97 June 20 7 .1 18 .8 16 .0 22.4 13 ,2 19.6 16.18 Morse May 1 26 .3 36.7 18 .7 31.2 28.23 May 10 . 36 ,9 22 ,6 26 .6 48.9 20 .3 30.6 30.98 May 20 35 .9 28 .8 22 .3 52.1 20 ,1 27.4 31.10 June 1 32 ,1 24 .5 13 .2 17 .8 37.4 25.00 June 10... 26 8 .0 17 .7 32.9 21.15 June 20 21 ,3 14 .2 25.2 20.23 194O\ ELEVEN YEARS OF SOYBEAN INVESTIGATIONS TABLE 19. (Concluded) 149 Variety and date seeded* 1926 1927 1928 1929 1930 1931 Average Hamilton May 1 15 .0 27 .1 15.1 32.5 22.43 May 10 . 31 ,2 25 .9 14 4 29 ,6 14.9 27.4 23.90 May 20 28 ,9 22 ,1 12, ,4 31 ,9 15.4 29.8 23.42 June 1 21 .3 23 .1 11 ,6 16.7 31.6 20.86 June 10 19 .4 28 .8 10 ,9 14.8 28.7 20.52 June 20 12 ,7 21 ,2 14.3 20.3 17.13 Midwest May 1 18 ,4 27 .6 13.5 23.7 20.80 May 10 24 ,1 25 .1 16 6 27 .6 13.0 19.9 21.05 May 20 24 ,1 20 .2 14 6 30 ,9 12.4 19.1 20.22 June 1 20, 3 19 ,8 11. 23, 8 11.1 21.5 17.92 June 10 13 ,7 24 .0 4, ,6 23 ,1 11.1 22.2 16.45 June 20 9 9 18, 4 10.7 19.0 14.50 Ebony May 1 20 .4 31 .3 11.5 28.7 22.98 May 10 . 27, ,9 31 ,1 11. 3 36, 8 15.5 30.4 25.50 May 20 29, 8 23 ,6 16, 5 35 .3 14.1 28.6 24.65 June 1 26. 5 25, ,9 9. 6 34. 1 13.9 29.5 23.25 June 10 22, ,7 32, ,0 10. 4 34, 4 13.3 28.1 23.48 June 20 13. 3 30. 7 15, 12.5 25.2 19.34 Dates seeded in any particular year were as near to dates recorded as climatic and soil conditions permitted. The highest average yield of each variety except Wisconsin Black was obtained from one of the May seedings (Table 19). Wisconsin Black, an extremely early variety, had the highest average yield from the June 10 seeding. EFFECTS OF STORAGE ON QUALITY OF SOYBEANS Soybeans stored for various periods of time and at different depths in the bin were tested for germinability, for stand and yield when planted, for shrinkage, and for chemical properties. Little experimental work on these problems had been done before these tests were made. Long Storage Reduced Stand and Yield Poor stands of soybeans, apparently resulting from the use of old seed or seed improperly stored, have been fairly frequent in Illinois, and consequently many inquiries from soybean growers have been received at the Illinois Station regarding the probable usefulness of soybean seed of different ages when stored under various conditions. Tests designed to answer these questions were begun in 1926. Half-bushel bags of seed of five varieties (Manchu, Lexington, Morse, Ilsoy, and Ebony) grown in 1926 were stored indoors in metal cans, and each spring beginning in 1927, seed from each variety was 150 BULLETIN No. 462 [January, TABLE 20. AGE OF SEED: EFFECT ON STAND AND YIELD OF SOYBEANS, URBANA, 1927-1934 Age of seed* Stand Yield Percent Compared with preceding year Compared with stand from new seed Bushels per acre b Compared with preceding year Compared with stand from new seed New 68 percl. points perct. points -2 -'2 - 8 -10 -12 -22 -13 -35 -16 -51 - 9 -60 - 3 -63 - 4 -67 29.6 28.9 27.6 28.2 25.4 18.2 11.1 6.1 2.1 bu. -".7 -1.3 + .6 -2.8 -7.2 -7.1 -5.0 4.0 bu. - ".1 - 2.0 - 1.4 - 4.2 -11.4 -18.5 -23.5 -27.5 1 year 66 2 years 58 46 4 years 33 5 years 17 6 years 8 7 years 5 8 years 1 "New" seed is seed used the year after it is grown; seed one year old is seed used the second year after it is grown; and so on. b Averages of five varieties, given in Table 21. planted in the field in rod rows / YIELD'' V (>,. ., .cr.) O I Z 3 4 5 t 7 6 AGE OF SEED IN YEARS FIG. 5. PERCENTAGE STAND AND ACRE- YIELD OF ILLINI SOYBEANS GROWN FROM SEED STORED ONE TO EIGHT YEARS The seed rapidly lost its viability after being in storage more than two years, but yields did not fall off markedly until the seed was more than three years old. replicated four times. Seed described in the following discussion and tables as "new" was that used the first crop season following its production. One- year-old seed was that used in the second crop season following pro- duction, and so on. The average yield of all varieties from the one-, the two-, and the three-year-old seed was only slightly less than the yield from new seed (Tab'* 20 and Fig. 5) ; but when seed stored four years or longer was used, yields were sharply reduced. The stand of plants, which is of course dependent upon field germi- nation, declined rapidly when seed older than two years was used. If weeds had not been well controlled by row cultivation, yields might have declined more rapidly as the number of plants was reduced. The black and the brown varie- ties, Ebony and Ilsoy, retained their vitality and yielding ability longer than the three lighter colored varie- ties Manchu, Lexington, and Morse 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 151 (Table 21 and Figs. 6 and 7) ; but in all varieties stands declined consistently with increasing age of seed. TABLE 21. AGE OF SEED: STAND AND YIELD OF FIVE VARIETIES OF SOYBEANS GROWN FROM SEED OF DIFFERENT AGES, URBANA, 1927-1934 Numbers of Age of seed seasons averaged Manchu Lexington Morse Ilsoy Ebony Stand Yield Stand Yield Stand Yield Stand Yield Stand Yield New . 8 perct. 64 58 44 29 13 2 bu. 33.6 34.4 29.7 27.3 22.1 6.6 1.4 perct. 69 59 55 46 29 13 7 1 bu. 25.5 23.1 20.8 22.4 24.8 14.0 6.9 .9 perct. 61 64 52 42 24 7 4 1 bu. 34.6 32.5 32.3 33.2 29.3 20.1 8.2 .7 Perct. 73 75 69 62 48 36 12 11 6 bu. 28.1 28.4 31.1 30.4 25.2 24.2 20.0 22.6 10.5 perct. 72 75 71 62 53 29 18 10 bu. 26.1 26.0 24.2 27.8 25.7 26.0 18.8 6.2 1 year 8 2 years 7 3 years 6 4 years 5 5 years 4 6 years 3 7 years 2 8 years 1 "New" seed is seed used the year after it is grown; seed one year old is seed used the second year after it is grown; and so on. I , 20 MORSE LEXINGTON 012345676 A6I OF SEED IN VEARS FIG. 6. ACRE- YIELDS OF FIVE VARIE- TIES OF SOYBEANS GROWN FROM SEED STORED ONE TO EIGHT YEARS Except for one variety, Manchu, yields did not fall off consistently as a result of loss of viability from stor- age until after the seed was four years old. Fluctuations during the first four years were due mainly to seasonal differences. 1" a 3 4 s AGE OF StED IN YEARS FIG. 7. PERCENTAGE STAND OF FIVE VARIETIES OF SOYBEANS FROM SEED STORED ONE TO EIGHT YEARS After the second year, stands de- clined steadily and rapidly. Stands declined more rapidly and consistently than yields, shown in Fig. 6. Even tho stands were very poor, yields often were satisfactory when weeds were fully controlled. 152 BULLETIN No. 462 [January, Shrinkage in Storage Tests on the shrinkage of soybeans stored under farm conditions were started at the Illinois Station in October, 1929. Approximately 215 bushels of Illini soybeans, weighing 12,905 pounds, were stored in a portable crib (Fig. 8). The beans had a moisture content of 11.1 percent. Crib and contents were weighed at weekly intervals. An empty check crib was weighed each time, so that any change in weight of crib could be eliminated in weighing the beans. The greatest loss in weight (73 pounds, about one-half of 1 percent) was during December, 1929, shortly after storage began, and the FIG. 8. GRAIN-DRYING AND STORAGE PLANT USED IN STORAGE STUDIES The drying and storage plant consists of eight cribs mounted on wheels so that they may be moved onto a track scale mounted in the center of a 200-foot track. Losses or gains in weight of grai* / during storage are thus readily measured. The sides of the cribs are of open construction, but for storage of soybeans they are sealed inside of the studding. greatest gain in weight (101 pounds) was during April, 1930 (Table 22). The weight of the soybeans varied directly with the relative humidity of the air and inversely with temperature (Fig. 9). During seasons when humidity was highest and temperatures lowest, the soybeans gained in weight; during the hot, dry summer months they lost weight. Altho no weights were taken of the beans at different levels in the crib, it was apparent that gains and losses in weight were not uniform thruout the depth of the crib, for there was marked variation in the maximum and minimum moisture contents of the beans from the various levels (Table 23 and Fig. 10) and this would affect their weight. Those on the surface had a maximum of 18.0 percent moisture 1940} ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 153 TABLE 22. MONTHLY WEIGHT CHANGES: ILLINI SOYBEANS STORED OVER FIVE-YEAR PERIOD, URBANA Year Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Pounds gain or loss from original weight of 12,905 pounds* 1929 23 19 26 21 3 11 -73 30 42 78 10 5 1930 . 52 88 45 79 28 -2 51 14 51 34 -5 101 47 58 43 39 100 39 60 56 -2 64 45 37 36 -52 46 13 45 4 21 22 -11 -41 -33 -39 9 15 4 -16 -11 15 24 -3 2 1931 32 1932 63 1933 17 1934 26 1935 -3 32 48 29 58 51 26 14 -8 8 17 15 Monthly average relative humidity and daily mean temperature (F.) Humidity 82.4 79.8 78.2 67.8 65.1 59.7 58.5 62.9 69 3 68.5 76 5 83 2 Temperature . 33 33 36 53 64 77 80 77 71 57 43 32 Because of variations in weight within a given month, the monthly weights were determined by averaging the weekly weighings. 100, 80 I" 9 "> ii * fc 41 JAN. FEB. MAR. APR. MAY JUNE JULY PT. OCT. NOV. DEC. FIG. 9. AVERAGE MONTHLY SHRINKAGE OF ILLINI SOYBEANS, RELATIVE HUMIDITY, AND TEMPERATURE, OCTOBER, 1929, THRU JANUARY, 1935 High temperatures and low relative humidity caused the shrinkage from month to month to be less in late summer than at any other time of year. 154 BULLETIN No. 462 [January, f> s I ^ o AND LABORATORY GERMINATION T DATES Urbana) Laboratory germination of seed from different depths in crib 9 o o o oQ - 1 ^C^5v OOO*O^O*OOI-"lOOb VOOOIOIO^H ^HCS '5J 1 1 10 fc ^ ' _ ^HO^^'OfM^H^^ O~*^*~*^H O*^^HO^H O'*^^^ f^ M 2- O - % ths in cri H^ft ~% ii fferent dep fO oo ^2 >> o * ^ _ ^^^-.(StSNO) (MINCMrOon fS N W5 W) . ffj VO >O fO n Pi < S OW u rt H g > ontent at ^co S "* .^r>-*-*^ tN^^rrj'^, ^,"^;^^ ,s, <> f"^H fc *"^ 0^ a H Moisture 8 1 a i C/J ^c 1 g = 1 J I 1 si! iNNNN |inH |iNN |NN i 10 1 liffi iii ii 1 ; J3 (2 -H CS ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 155 3" 18.0 MAXIMUM PERCENT MOISTURE MINIMUM PERCENT MOISTURE 4 FEET BELOW SURFACE FIG. 10. MAXIMUM AND MINIMUM PERCENTAGES OF MOISTURE IN SOYBEANS AT VARIOUS LEVELS IN STORAGE CRIB, NOVEMBER 26, 1930, TO FEBRUARY 7, 1935 Moisture content in the soybeans at the lower levels of the crib was much more stable than in those at the upper levels. It was this greater uniformity of moisture that was chiefly responsible for the beans at the lower levels retaining their viability longer than the others (Figs. 11 and 12). and a minimum of 7.7 percent, a variation of 10.3 points. Those on the bottom of the crib, 4 feet below the surface, had a maximum of 12.4 percent and a minimum of 10.5 percent, a variation of only 1.9 points. Variations in moisture content of beans from other levels in the crib were intermediate between the variation at the top and that at the bottom. Germination Tests of Stored Beans The germinability of soybeans stored under farm conditions was also studied in connection with the tests just described. Effects of both length of storage and depth of the beans in the crib were in- vestigated. At frequent intervals samples were taken with a grain trier from the surface of the beans in the crib and from approximately 1, 2, 3, and 4 feet below the surface. Samples were collected twenty- six times at more or less regular intervals beginning one month after the date of storage and continuing until the beans were removed on February 7, 1935. 156 BULLETIN No. 462 [January, FIG. 11. GERMINATION OF ILLINI SOYBEANS FROM VARIOUS LEVELS IN THE STORAGE CRIB (A) Samples taken December 30, 1929; (B) samples taken December 1, 1930. The figures shown on the individual squares indicate the depth in the crib from which the samples were taken: S = surface; 1 = 1 foot below the surface; 2 = 2 feet below surface; and so on. 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 157 FIG. 11. Concluded (C) Samples taken July 28, 1932; (D) samples taken April 26, 1934. The superior viability of seed from the lower levels in the crib is again illustrated. CK = Illini seed of preceding season. 158 BULLETIN No. 462 [January, Laboratory tests of germinability. The germirtating quality of the soybeans from the upper levels of the crib deteriorated rapidly in storage, according to laboratory germination tests. On May 3, 1930, when the beans from this crib would normally have been planted by farmers as high-quality new seed, the surface samples germinated only 92 percent, those from a foot beneath the surface germinated 97 per- cent, and those from the lower depths germinated 100 percent (Table 23 and Fig. 11). Four months later, on September 8, the beans from the surface and those from a foot below the surface germinated only 73 and 78 percent respectively, whereas those collected from 2, 3, and 4 feet below the surface germinated 97, 100, and 100 percent. In the spring of 1930 the average germination during the four- month period April thru July varied from 90 percent on the surface to 99 percent 3 and 4 feet below the surface (Fig. 12). In April, 1931, at which time the seed was a year old, germination was further re- duced to 59 and 73 percent respectively at the surface and a foot below the surface, while seed from the deeper levels germinated 93 percent or better. This deterioration of the seed at the upper levels of the crib was caused by the greater absorption of moisture at these levels than at the bottom. The crib used in this study was probably as nearly moisture-proof in construction as the average farm storage crib. Slight amounts of snow sifted under the eaves of the crib, however, during the tests, and contributed somewhat to the poor germination of the surface beans. The germinating quality of soybeans stored in farm cribs thus de- pends not only upon the age of the seed, but also upon the condition of the crib, the moisture content of the beans at the time of storage, and the depth of the beans within the crib. Beans having a fairly high moisture content at harvest cannot, without injury to their viability, be stored as deep in the crib as the beans in this study were stored. Field tests for germination and yield. Beginning in 1932 seed from the stored beans was planted in the soybean nursery in rod rows (four replicates of each sample) to determine germination and yield of two-, three-, and four-year seed taken from the surface and from 1, 2, 3, and 4 feet below the surface of the crib. In these field tests percentage of germination of the seed from each level was lower than in the laboratory tests. Yields from this seed, however, were not as much below yields from new seed as might be expected a fact in keeping with the results in the rate-of -seeding tests (pages 142 to 146). 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 159 Two-year-old seed from the surface and from 1 and 2 feet below the surface, that germinated 12 to 36 percent in the laboratory, germinated only 8 to 20 percent in the field, and the yield in the field was only 45 and 65 percent as great as that obtained from high- quality new seed (Table 24). Two-year-old seed from levels 3 and 4 feet below the surface, that germinated 68 and 72 percent in the laboratory, germinated only 52 and 61 percent in the field and yielded 99 and 92 percent as much as new seed. TABLE 24. DEPTH OF STORAGE: EFFECT ON GERMINATION AND YIELD OF ILLINI SOYBEANS (Seed stored October, 1929 at Urbana; planted in field in 1932, 1933, and 1934) Relative yields from seed of different ages Depth in crib Germination of seed at (new seed = 100) 2 years' 3 years* 4 years* 2 years* 3 years* 4 years* (1932) (1933) (1934) (1932) (1933) (1934) At surface perct. 12 perct. perct. perct. 59 perct. perct. 1 foot below surface 8 45 2 feet below surface 20 65 3 feet below surface 52 7 99 53 4 feet below surface 61 20 2 92 75 9 Check (new seed) 71 24 90 100 100 100 Two, three, and four years after the seed would normally have been used, in this case in 1930. By 1933 all the seed, then three years old, was unsatisfactory for planting. Only that taken from 3 and 4 feet below the surface germinated at all and then only 9 and 45 percent respectively in the laboratory 7 and 20 percent in the field. Yields were only 53 and 75 percent, respectively, as much as from new seed. In 1934 the only four-year-old seed that germinated in the field came from the bottom of the crib 4 feet below the surface, and only 2 percent of it germinated. The yield of beans from the plants grown from this seed was only 9 percent as much as from new seed. Chemical Composition of Three-Year-Old Beans When the beans had been stored more than three years, a number of chemical analyses were made of samples taken from various depths in the storage crib, to determine possible relationships between vitality and chemical composition. This was in January, 1933. The beans were analyzed for acid number, carbohydrate content, iodin number, refrac- tive index, oil content, protein content, percent total nitrogen, and percent soluble nitrogen. 160 BULLETIN No. 462 SURFACE [January, NDJ FMAMJ.JJASON D J F M A MJvJ, A S N J F M A MJuJ, A S N D ( J F MAMJ.JyA S N D,J F M A 1929 1930 1931 1932 1933 1934 NEW SEED ONE YR OLD TWO YRS. OLD THREE YRS. OLD FOUR YRS. OLD ONE FOOT BELOW SURFACE 100 " " b 40 1* 20 10 <** y*"^ / - v x V 20 "I J K 'I Jc N J F MAMJ.J, A S N D J F MAMJ-^AS N D J F MA MJuJyAS OH D J F MA MJuJyAS NO JF MA 1929 1930 1931 1932 1933 1934 NEW SEED ONE YR. OLD TWO YRS. OLD THREE YRS OLD FOUR YRS OLD 100 $ 80 K 70 TWO FEET BELOW SURFACE 20 NDJ F M A MJ.J, AS ON D J F HAMJiJ^AS N J F M A M J.Jy A S N D J F MAMJ.JjASO N D JF MA 1929 19 T ,0 1931 1932 1933 1934 YR5. NEW SEED ONE YR. OLD TWO YRS. OLD THPEE YR5.0LD FIG. 12. GERMINATION AND MOISTURE CONTENT OF ILLINI SOYBEANS FROM VARIOUS LEVELS IN THE STORAGE CRIB, NOVEMBER, 1929, TO APRIL, 1934 (Graph is concluded on next page.) 1940\ 1 00 ^ 90 80 I ELEVEN YEARS OF SOYBEAN INVESTIGATIONS THREE FEET BELOW SURFACE Moisture I Germination 161 20 '1 -I k 8 N J FMAMJi-lyASO ND J F M A MJ.J, AS M D J F M A MJ.J, A SON D J F MAMJ.JyAS ON D J F MA 1929 1930 1931 1932 1933 1934 NEW SEED ONE YR. OLD TWO YRS. OLD THREE YRS. OLD FOUR YRS. OLD FOUR FEET BELOW SURFACE 20 N D J F MAMJu-lyAS OMD.JF MAMJ.JyAS ON D J F MAMJuJyAS ONDJF MAMJu^ASONDJFHA 1929 1930 1931 1932 1933 1934 NEW SEED ONE YR. OLD TWO YRS. OLD THREE YRS. OLD FOUR YRS. OLD FIG. 12. Concluded Wide fluctuations in moisture content of the beans in the upper levels of the crib were accompanied by low germinability of those beans ; and fairly uniform moisture percentages in the lower levels were accompanied by high germinability. Beans from the upper levels were of doubtful worth for seed even in the first planting season following storage. In the samples taken from the surface and from 1 and 2 feet below the surface the acid numbers were considerably higher than in the samples from the 3- and 4-foot depths (Table 25). lodin number, refractive index, oil content, protein content, percent total nitrogen, per- cent soluble nitrogen, and carbohydrate content all varied only slightly in the samples from the different depths. These slight variations do not help to explain the extreme differences in the vitality of the seed. To determine whether diastatic activity, as indicated by loss of carbohydrate content, was limiting germination, further tests were made 162 BULLETIN No. 462 [January, on samples collected from the various levels of the crib on April 18, 1933. No relation, however, was found between diastatic activity and percentage of germination. TABLE 25. DEPTH OF STORAGE: EFFECT ON PROPERTIES OF MEAL, OIL, AND WHOLE GRAIN OF SOYBEANS (Beans stored October 25, 1929, at Urbana, and sampled for analysis on January 25, 1933) Oil Depth in crib Acid number lodin number Refractive index at 25 C. Carbohy- drate" At surface . . . perct. ... . 14.36 2.20 2.39 2.53 1.56 1.09 126.49 128.27 125.49 127.33 127.73 1.4741 1.4740 1.4740 1.4739 1.4739 1 foot below surface 14.14 2 feet below surface 13.43 13.73 4 feet below surface 14.33 Seed Oil Protein Total nitrogen Soluble nitrogen Nitrogen difference At surface perct. 22.5 perct. 34.78 perct. 7.66 perct. 5.94 1.72 1 foot below surface 22.2 34.49 7.26 5.64 1.62 2 feet below surface 22.4 34.97 7.32 5.96 1.36 . . . . 21 36 74 7.64 6 65 99 4 feet below surface 21.8 35.85 7.32 6.24 1.08 Carbohydrate values by diastace hydrolysis of expressed meal. 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 163 SUMMARY AND RECOMMENDATIONS Yields and general performance of approximately 65 varieties and strains of soybeans were tested and observed by the Illinois Agri- cultural Experiment Station during the eleven years 1927 to 1937, in continuation of trials begun at this Station in 1906. The beans were planted on experiment fields in northern, central, and southern Illinois, and the yields of hay and straw as well as of grain were measured. Supplementary tests were made of the proportion of leaves, stems, and pods in soybean hay before and after field-curing. Tests were made also of the effects of different dates, rates, and methods of seeding on yield of grain, of the effects of storage on germinability and chemical properties of the seed, and of amount of shrinkage of beans stored under farm conditions. Illini soybeans were used in these tests on seeding practices and effects of storage. Varieties 1. As the result of these tests the following varieties of soybeans are recommended for grain production in the various sections of Illi- nois. The recommendations are based not only on quantity yields, but also on performance in such other respects as shattering, lodging, color of bean, and time required for maturing. Northern Illinois Southern Illinois Manchu Selection (Thomas) Morse Selection 230 Manchu (Thomas) Scioto Manchu (Wisconsin) Mansoy Strain B Macoupin Black Eyebrow Manchuria 13-177 Central Illinois Illini Illini Dunfield Manchuria 13-177 Manchu 2. Strictly hay varieties did not in general yield either more or better hay than the grain varieties. Thus there appears to be no reason for farmers to change their present practice of growing grain- type beans for hay. 3. Soybean plants of 16 varieties in the best stage of growth for hay production (pods well filled but leaves not yet starting to fall) averaged approximately one-third leaves, one-third stems, and one- third pods, when the different parts were oven-dried and weighed. 4. During the process of field-curing and harvesting 24 varieties of soybeans for hay, approximately 74 percent of the oven-dry weight 164 BULLETIN No. 462 [January, of the leaves, 77 percent of the stems, and 89 percent of the pods were saved. 5. Straw yields of the soybean varieties recommended for northern Illinois averaged 1.14 tons an acre; those for central Illinois 1.20 tons an acre; and those for southern Illinois 1.14 tons an acre. Seeding Practices 6. Beans seeded in rows 24 inches apart gave higher acre-yields than those seeded in rows 8 inches apart. 7. Increasing or decreasing the rate of seeding showed no con- sistent effect, over a period of five years, on grain yields. For beans drilled in rows 8 inches apart, seedings of 90 to 130 pounds an acre averaged slightly better yields than the other rates; and for beans drilled in rows 24 inches apart, seedings of 50 to 70 pounds an acre averaged slightly better yields than the other rates. 8. May seedings produced higher grain yields than June seedings, as an average of 12 varieties; but there were no marked differences in yields from the different May seedings May 1, May 10, and May 20. Storage 9. Beans grown from seed stored indoors in metal cans and planted one, two, and three years after the spring following harvest, averaged slightly lower grain yields than beans grown from seed planted the spring following harvest. Beans grown from seed stored in this way for four years or longer gave sharply reduced grain yields. 10. The moisture content of soybeans taken from various depths in the outdoor test crib varied considerably. Those at the upper levels of the crib absorbed moisture more rapidly than those at the lower levels. This crib was representative of farm cribs in construction and care. 11. The germinability of soybean seed stored in the outdoor crib varied with the age of the seed and its depth in the crib. Beans from the upper levels showed reduced vitality even in the first spring following harvest, and when two years old they were worthless as seed. Beans from the lower levels retained their vitality fairly well until the third season following harvest, but when planted the fourth season they were of little value. 1940] ELEVEN YEARS OF SOYBEAN INVESTIGATIONS 165 12. Greater acidity was found in beans from the upper levels of the outdoor crib after three years of storage than in beans from the lower levels. Other chemical properties (iodin number, refractive index, oil content, protein content, percent total nitrogen, percent soluble nitrogen, and carbohydrate content) were not especially affected by depth of storage. (Characteristics of the soybean -varieties included in the trials reported in this bul- letin are described on the following pages.) 166 BULLETIN No. 462 [January, p >. > 1 2 B A) E B E B ^ j^ E E E E E ^ j^ ^ B B B E 1 HOH O HHHHOO linn 555558 HHHHHO 2> cd > ed ? 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S. Ill's =,y ti^i^g o : ;BO : . . VOQ - ^ - ; i ' ^C/3C/2QQCfl g|H U OT3T3 a) 5 > O V 4J QJ *O ^ 2* O c P c ' o o fs o o o^ oo f*> rt C C C C C^ iiiui lilill IMlil O'O>O< r >rjU5 STf ^ 10 10 * M)H) v w vj *o 120SO 1-40 18023 UNIVERSITY OF ILLINOIS-URBANA