104 THE BOOK OF CORN 



In the case of wheat and grass, an application of 

 organic nitrogen in slowly available forms would not 

 result in an increase in crop, because the conditions 

 that are not favorable to the change of the nitrogenous 

 material in the soil would apply just the same to those 

 applied, and the result would be that the plant could 

 not obtain it. Hence for those crops the nitrogen 

 should be in a soluble and active form, so that it may 

 be readily distributed and that the crop may obtain it 

 at once. Whereas, in the case of corn grown upon land 

 deficient in nitrogen, organic forms, which are likely 

 to change rapidly, owing to the favorable conditions, 

 would be likely to be quite as useful as the soluble and 

 immediately available forms, because these might be 

 carried away from the plant by the rains that are 

 usually abundant during this season. 



From these considerations, it will be observed that 

 no positive and definite rules can be given as to the 

 kind and amount of application, but only broad, general 

 rules, which must be interpreted by the farmer himself 

 for his peculiar conditions. 



RESULTS OF EXPERIMENTS 



The experiment stations of the country, particu- 

 larly those of the eastern and southern states, have 

 carried out experiments to determine the fertility needs 

 of different soils and crops. Widely varying results 

 have been obtained, chiefly for the reasons already out- 

 lined. In a broad general way, the results in the east- 

 ern states show that of the minerals, potash seems to 

 be needed especially for corn, while in the southern 

 states phosphoric acid is the chief constituent lacking, 

 though upon lands naturally poor, the addition of all 

 of the constituents is required, if maximum crops are 

 obtained. 



