8 MISCELLANEOUS PUBLICATION 952, U.S. DEPT. OF AGRICULTURE 



Table 3. — Changes in nitrogen content in 0- to 24-inch depths in 2 soils 

 with different rotations and fertilizer treatments, Mandan, N. Dak.. 

 1949-55 1 





Annual application, 

 per acre, of — 



Gain or loss of 

 nitrogen in — 



Rotation 



N 



P 2 5 



Cheyenne 



fine sandy 



loam 



Agar silt 

 loam 



Wheat 



Pounds 







30 







30 



60 











Pounds 

 

 30 

 

 30 

 30 

 30 

 30 



Percent 

 -3 

 + 1 

 -1 

 

 + 1 

 + 1 

 + 1 



Percent 

 — 3 



Do 



+3 



Crested wheatgrass 





Do 



+ 3 



Do 



+2 



Crested wheatgrass and alfalfa 



Crested wheatgrass and sweetclover__ 



+ 3 







i Data from Haas, see footnote 3, p. 7. 



Table 4. — Changes in nitrogen content in 0- to 24-inch depths of Cheyenne 

 soil with different rotations and fertilizer and harvesting treatments, 

 Mandan, N. Dak., 1949-57 1 



Rotation, 1949-55 * 



Annual application 



(1949-55), per acre, 



of — 



Gain or loss of nitrogen 



(1949-57) when 



crop was — 





N 



P2O5 



Harvested, 

 1949-55 



Not 



harvested, 



1949-55 



Wheat 



Pounds 







30 







30 



60 











Pounds 

 

 30 

 

 30 

 30 

 30 

 30 



Percent 

 -3 

 -2 

 -3 

 

 + 2 

 + 2 

 + 2 



Percent 

 -3 



Do 



— 2 



Crested wheatgrass 



— 5 



Do 



+ 1 



Do 



+3 



Crested wheatgrass and alfalfa 



Crested wheatgrass and sweetclover__ 



+ 7 



+ 3 



1 Data from Haas, see footnote 3, p. 7. 



2 All plots cropped to spring wheat in 1956 and 1957. 



grass plots showed nitrogen losses. 

 Nitrogen losses were not decreased 

 in the half of each plot on which 

 the residue was left on the surface. 

 Annual applications of 30 pounds 

 of nitrogen on the crested wheat- 

 grass maintained the initial nitrogen 

 content. Sixty pounds of nitrogen 



produced a slight increase in the 

 nitrogen content of the soil of 

 both harvested and nonharvested 

 plots. 



Furthermore, his data show that 

 phosphorus fertilization of mixed 

 crested wheatgrass and alfalfa or 

 sweetclover produced a slight gain 



