230 Report on Crop Production. 



to be 'Continuously used. The outcome of extensive experiments 

 for four years on four farms presents good reasons for question- 

 ing the wisdom, under the conditions involved, of applying more 

 potash on potatoes than any other ingredient. It is now a trite 

 statement, but a true one, that each farmer must discover for 

 himself the fertilizer needs of his farm. Such experiments as 

 these are suggestive, but the results are put to their be^ use 

 when they serve as the basis for similar observations by indi- 

 vidual farmers. 



One fact, no less important than any other mentioned, to which 

 these experiments point, is that the proportion of available plant 

 food in the soil is only one factor in crop production. It is not 

 enough that a plant have within reach all the raw materials 

 from the mineral world that it needs for luxuriant growth. Its 

 environment must be congenial both in the soil and out of il^ 

 if the raw materials are to be appropriated to the maximum 

 extent. This means that soil texture and warmth, conditions 

 which are largely dependent upon culture and the supply of 

 humus, must be given careful attention. The result of neglect- 

 ing these conditions can never be fully overcome by the liberal 

 purchase of fertilizers. 



