LOSS OF NITRATED 



155 



as 100 per cent, and that of the unirrigated as 100 per cent., the 

 manured and irrigated soils then become with 5 tons of manure, 147 

 per cent.; with 15 tons of manure, 188 per cent.; 5 inches of water, 

 106 per cent.; 10 inches of water, 117 per cent.; 20 inches of water, 



5 TONS 

 OF MANURE 



15 TONS 

 OF MAN.URE 



FIG. 23. Diagram showing the influence of manure on the yield and bacterial activi- 

 ties of a soil. The unmanured soil is expressed as 100 per cent. 



108 per cent. Large quantities of irrigation water produced the 

 greatest depressing effect in the presence of 15 tons of manure to the 

 acre. 



Fewer organisms develop on synthetic agar from a cropped than 

 from a fallow soil. The application of manure to a cropped soil 



