Methods of Use of Fertilizers 195 



tribution throughout the mass by the percolation of the 

 water through them ; while certain others are so compact, 

 owing to the finely divided particles, that even though they 

 were abundantly supplied with all of the necessary mineral 

 constituents, profitable crops could not be grown because 

 the roots could not readily penetrate, and because the 

 water falling upon the land would not readily pass through, 

 but remain upon the surface. 



In the case of soils with an abundance of lime, physical 

 qualities also exercise a very considerable influence, even 

 though there is a sufficient supply of all of the fertility 

 elements. Certain of them are too cold, others are too dry, 

 and the mechanical condition is such as to prevent the 

 proper and uniform growth of plants. It must be remem- 

 bered, then, that only general rules apply in the use of 

 fertilizers upon soils of the different classes, and that they 

 are modified by both the chemical composition and the 

 mechanical condition of the soils. The best use of a fer- 

 tilizer that is, the greatest proportionate return of 

 plant-food in the crop, all things considered is obtained 

 from its application upon soils that possess "condition," 

 or that are well cultivated or managed. Full returns can- 

 not be expected when they are applied upon soils that are 

 too wet or too dry, too porous or too compact, or too coarse 

 or too fine. It is important that even the best soils should 

 be properly prepared, and it is infinitely more important 

 that those which possess poor mechanical condition should 

 be improved in this respect, before large expenditures are 

 made for fertilizers. 



The influence of previous treatment and cropping. 



In the next place, the previous treatment and cropping 

 of soils should guide in the use of fertilizers, since soils of 



