32 MISCELLANEOUS PUBLICATION 95 2, U.S. DEPT. OF AGRICULTURE 



His data (tables 23 and 24) 

 indicate that nitrogenous fertilizer 

 was more effective than sweetclover 

 in increasing corn yields in 1953 

 and 1955. The optimum rate of 

 nitrogenous fertilizer varied with 

 yield level and rainfall. 



Summary 



Rye and pea green-manure fallow 

 reduced yields of winter wheat, 



spring wheat, and oats below those 

 for ordinary fallow at ScottsblufT 

 and North Platte. At North Platte, 

 in favorable years green manures 

 plowed down 3 years previously had 

 some beneficial effect. In unfavor- 

 able years, pea green manure plowed 

 down 3 years previously reduced 

 wheat yields. Four years of weeds, 

 bromegrass, and sweetclover had 

 no differential effect on succeeding 

 yields of wheat and corn. 



Table 23. — Yields of corn in legume and nonlegume rotations during years 

 of varying rainfall, Lincoln, Nebr., 1947-56 l 



Year 



Rainfall 



Yield, per acre, of 

 corn under — 



Gain or loss, 

 per acre, 





Legume 

 rotation 2 



Non- 

 legume 

 rotation 3 



with 

 legume 

 rotation 



1947 



Verv high. 



Bushels 



27.9 

 80.7 

 61.2 

 101.6 

 20. 5 

 52.7 

 35.3 

 26. 8 

 62. 1 



Bushels 



28.7 

 47. 2 

 46.6 

 62.4 

 23. 5 

 34. 6 

 46. 

 32. 1 

 62.9 



Bushels 

 -0. 8 



1948 



Favorable. __ _ 



+ 33. 5 



1949 





+ 14. 6 



1950_ 



Favorable 



+ 39. 2 



1951 



Verv high. __ _ _ 



-3. 



1953 _ 



Low but timely _ 



+ 18. 1 



1954 



Not timely . _ _ 



-10.7 



1955 



1956 



Low 



do 



-5.3 



-. 8 









Mean__ _ 



52. 1 



42.7 



+ 9. 4 









! 



i Data from Duley (16). 



2 Sweetclover, sweetclover, wheat, corn, oats. 



3 Corn, oats, wheat. 



Table 24. — Yields of corn with no nitrogenous fertilizer and with 4-0 and 

 80 pounds per acre, on subtilled land, Lincoln, Nebr., 1958-55 l 



Year 



Rainfall 



Grain yield, per acre, with 



indicated pounds of nitrogen 



(per acre) 









40 



80 



1953 



Low but timely 



Bushels 

 48.2 

 45. 1 

 31.2 



Bushels 

 51.4 

 44.7 

 39.0 



Bushels 

 61.0 

 48.3 

 31. 1 



1954 



Not timely. _ _ 



1955 



Low. 







' Data from Duley (16). 











