206 



Percentage and amounts per acre of nitrogen in tops and in 



roots and sttibble. 



The quality as well as the quantity of the crop was very 

 favorably influenced by inoculation, the percentage of nitrogen 

 in the tops being practically doubled. The higher the per- 

 centage of nitrogen the greater is both the food value and the 

 fertilizer value of a plant. 



The tops of the rye, including the nearly mature grain 

 and the straw, contained only 0.52 per cent, of the nitrogen, or 

 less than one fifth as much as was contained in the tops of 

 inoculated vetch plants. The roots of rye contained only 0.35 

 per cent, of nitrogen, or about one-fourth as much as the 

 roots of inoculated vetch plants. 



Of intense practical interest are i.he figures showing the 

 amount of nitrogen per acre contained in the several crops. 

 Vetch on one acre contained in the entire plant 105 5 pounds 

 of nitrogen, rye only 26 pounds, or about one-fourth as much, 

 and the dwarfed vetch plants still less than rye. 



We may get some measure of the superiority of inocu- 

 lated vetch over rye as a fertilizer by noting the fact that the 

 nitrogen in one acre of the former exceeded that in an equal 

 area of rye by 79.5 pounds. This 79 5 pounds of nitrogen 

 would represent approximately the amount of nitrogen as- 

 simulated by vetch /?'om the air, it we should assume that vetch 



