1020] FIELD CROPS. 331 



luillol hay grown on adjoinin;,' plats. The averagt> hay yiehl for ilu,' hist two 

 years was 0,058 lbs. jtcr acre, as compared with S,-'2{) li)S. i'or sorf^luini and 

 3,997 lbs. for (Jolden millet. 



Among tlie results secured from improving field crops by breeding and selec- 

 tion, soy beans in the variety test plats px'oUiiced numerous natural hybrids, 

 sliowing that artificial liybridization is not necessary to produce new sorts. 

 Corn selected continuously for 13 years from plants producing no suckers 

 slioweil no advantage in yield and quality over corn not so selected and pro- 

 ducing sui'Ivers freely. The results of cooperative pasture experiments indi- 

 cate at this time that redtop, Kentuclcy blue grass, and slieep's fescue are the 

 most promising grasses, and alsike clover and white clover the most promising 

 leguminous plants for pasture purposes ou the greater part of the uplands in 

 southern Indiana. 



Experiments in tlie failure of clover led to the conclusion that lime, organic 

 matter, and fertilizers, especially acid phosphates, are important factors in 

 restoring clover-sick land. In one experiment an application of wheat straw 

 as organic matter resultetl in a clover hay yield of 3,200 lbs. per acre the lirst 

 year, as against an average of 1,440 lbs, on untreated land, wlule on land 

 receiving lime 2,SSS lbs. and on land treated with fertilizers 3,000 lbs. per 

 acre were secured. In an experiment conducted for five years the clover hay 

 yields on limed land averaged 3,404 lbs. as against 2,656 lbs. on initreat':(l hiuil 

 in one test, and 3,516 lbs. as against 2,074 lbs. per acre in laiother. In a third 

 experiment the yield of clover hay on untreated land was 1,350 lbs., with iime 

 2,660 lbs., and with both lime and phosphate 4,930 lbs. 



[Report of the department of agronomy], G. Roberts {Kentucky Sta. Rpt. 

 191S, i>t. 1, pp. 22-28). — The work for the calendar year 1918 was continued 

 mainly as previously noted (E. S. R., 39, p. 422). 



The status of the woi-k on the soil experiment fields in vari.)us p.irts of the 

 State is briefly described, and the results with tobacco on the Greenville field 

 and with sweet clover on the Berea field are reported. The tobacco was grown 

 in a 3-year rotation with wheat and clover, and the soil v.-as either left mi- 

 treated or received different combinations of 2 tons of limestone, 600 lbs. of 

 acid phosphate and 150 lbs. of sulphate of potash per acre applied only to the 

 tobacco crop, and 100 lbs. of nitrate of soda per icre used on the tobacco and 

 wheat crops. The average yield of five tobacco crops given the complete appli; 

 cation without limestone was 1,209 lbs.; limestone and acid phosphate 1,119 

 lbs.; the complete aiiplication with limestone 1,108 lbs.; and lin)estone, acid 

 phosphate, and nitrate of soda, 1,047 lbs. per acre, as against 456 lbs. per acre 

 without hvatment. The best yield of clover, 4,313 lbs. per acre, the average 

 of ft.ur crops, was secured with limestone and acid phosphate, and of wheat, 

 28.2 bu. r»er acre, the average of two crops, with limestone, acid phosphate, and 

 nitrate of soda. 



The sweet clover, on soil receiving lime and acid phosphate and seeded in the 

 spring of 1916, produced 278 lbs. of marketable uiduilled seed per acre. The 

 straw was s])read on the ground and plowetl imder in the fall. The succeeding 

 corn crop in 1918 yielded 40 bu. per acre as compared with 20 bu. on untreated 

 soil on which sweet clover would not grow. 



The results of cultivation experiments with corn for eight years showed Imt 

 little variation in the yield from the different methods of cultivation. No cul- 

 tivation, with simply scraping off the weeds, gave .52 bu. per acre and from seven 

 to eight cultivations 4 in. deep gave 55.2 bu. per acre, these being the lowest 

 and highest yields, respectively, in the series of tests. When soy beans were 

 drilled in the rows with the com or in alternate rows the total value of the 



