LEGUMES AND GRASSES 



31 



Department of the Nebraska Agri- 

 cultural Experiment Station began 

 cooperative studies on the Pierce 

 Soil Conservation District farm in 

 Pierce County. Chief soil conser- 

 vation problems were: (a) prevent- 

 ing wind and water erosion and (b) 

 increasing crop yields through im- 

 proved soil fertility. 



They reported that wind and 

 water erosion were controlled ef- 

 fectively by (a) keeping the land 

 covered with a vigorous-growing 

 crop as much of the time as possible 

 and (b) keeping the residue from 

 the previous crop on the surface to 

 prevent soil movement by wind 

 when there was no crop growing on 

 the land. Large yields of residue 

 were necessary to protect the soil 

 in the interval between crops. 



They found that supplemental 

 nitrogen was necessary to improve 

 grain and forage yields. Their ini- 

 tial effort to supply more nitrogen 

 was by growing more legumes. 

 Their tests proved that vetch and 

 partridgepea can be grown on these 

 sandy soils without special soil 

 treatment but that lime and phos- 

 phate improved their growth and 

 effect on succeeding crops. Sweet- 

 clover, lespedeza, and alfalfa were 

 grown successfully where the soil 

 has been limed and phosphated 

 (table 22). 



Vetch and biennial sweetclover 

 were considerably more effective in 

 increasing corn yields than the other 

 three legumes. Inorganic nitrogen 

 also produced profitable yield re- 

 sponses when applied to nonlegume 

 grains and grasses. 



Comparisons between legume and 

 commercial nitrogen were limited 

 to rye in 1952. Vetch was more 

 effective in increasing rye grain 

 yields than was 33 pounds of am- 

 monium nitrate. Partridgepea was 

 about equal to 33 pounds of ammo- 

 nium nitrate. Unfortunately, other 

 rates of nitrogen were not used. 



Duley (16) reported on yieldsTin 

 different cropping systems and fer- 

 tilizer treatments under stubble 

 mulching and plowing in eastern 

 Nebraska. Soil type was Sharps- 

 burg silty clay loam, rolling phase, 

 at the University of Nebraska. He 

 gave yields from legume and non- 

 legume rotations during years of 

 varying moisture supplies (table 

 23). 



His data (table 23) indicate that 

 in certain years higher yields were 

 obtained from the nonlegume rota- 

 tions than from rotations including 

 sweetclover. These were usually 

 the years of extreme moisture con- 

 ditions, either too wet or too dry. 



Duley (16) conducted a separate 

 fertilizer experiment with corn on 

 sub tilled land for 3 years (table 24). 



Table 22. — Average yields of corn in legume and nonlegume rotations and the 

 increase from the legume, Sandy Land Farm, Pierce, Nebr., 1951-62 12 



Previous-year crop 



2-year mean 



corn yield, 



per acre 



Increase, per 

 acre, over 

 no legumes 



Vetch 



Biennial sweetclover. 

 Annual sweetclover. 



Lespedeza 



Partridgepea 



No legumes 



Bushels 

 59.6 

 56.6 

 47.2 

 35.8 

 32.4 

 27.0 



Bushels 



32.6 



29.6 



20.2 



8.8 



5.4 



» Data from Duley and coworkers (20). 

 2 1 ton of lime per acre was applied in 1950; 



711-108—64 5 



pounds P2O5 per acre at legume seeding in 1950 and 1951. 



