118 



The chemical industries supplying plant foods and the purchaser of 

 these products would both be greatly benefited by the inauguration at our 

 experiment stations in the grain growing section of experiments properly 

 planned to solve the question of the most profitable method of supplement- 

 ing the plant food resources of the farms. 



Up to the present time it must be confessed that the purely empirical 

 methods of the fertilizer manufacturers have produced results that yield 

 the farmer better returns than anything derived from the experiments 

 started under the old system by the educational institutions in the grain 

 growing section, but these are far from being the best obtainable. Both 

 farmer and fertilizer manufacturer need the help of the educational insti- 

 tutions in the direction of securing facts relative to the most profitable 

 methods of utilizing plant foods in the production of our great cereal crops 

 — facts that will help and not discourage. 



But such experiments must take into consideration 



The kind of materials to use, 



The avoidance of indirect effects, 



The right methods of application. 



The question of the most profitable amount, and finally 



The rational interpretation of the results obtained. 

 German Kali Works, Chicago, 111. 



