216 Fertilizers 



plify the work in the beginning, only the first four plots 

 need be taken. This will reduce the labor, and, at the 

 same time, permit a study of the soil's deficiencies in 

 respect to single elements of plant-food, and the relative 

 needs of the different crops for the various constituents. 



The rate of application to the acre is greater than would 

 naturally obtain in practice, in order to facilitate the dis- 

 tribution of the fertilizer, to furnish a sufficient abundance 

 of the constituent, and to provide against unfavorable 

 conditions. 



Preferably, the application should be made broadcast, 

 and before planting, though for cultivable crops it may be 

 applied later and harrowed into the soil. 



It will be observed that the amounts of fertilizer are 

 one pound to the square rod, or multiple thereof. Thus, 

 in order to insure an equal distribution over the entire 

 area, it may be roughly divided into plots of a square rod, 

 and the required material for each rod applied separately. 

 Careful weights should be made of the yields of the dif- 

 ferent plots, as a basis of comparison. The same ferti- 

 lizers should be used on the different crops of the rotations, 

 and as interest is increased in the work, different forms 

 and amounts of the various constituents may be intro- 

 duced. 



Results that may be attained. 



If it is found that for a certain crop only one of the 

 applied constituents profitably increases the yield, then 

 that should be used until the need of the others is appar- 

 ent. If two are needed to accomplish the results, use 

 two, and so on; though in the long run, or as the prac- 

 tice approaches the "intensive" system, all will doubt- 

 less be required. In "extensive" farming this is a very 



