56 



Fertilizers 



the results obtained by different workers under average 

 conditions. It also shows the recovery of nitrogen from 

 different forms. The values given are far from fixed, 

 since changed conditions of soil, climate, crop and the 

 like may modify them to a considerable extent. At 

 all events, they are a fair approximation of the actual 

 conditions as they exist in most soils. 



Comparative availability of different nitrogenous substances. 



The author's figures in this table furnish a fair basis for 

 comparing the different materials, when used for the 

 same purpose or under the same conditions. If, for 

 example, the increased yield of oats due to the applica- 

 tion of nitrate of soda is 1000 pounds, the yield from blood 

 and cotton-seed meal would be 700 pounds, the yield 



