CHAPTER XVIII. 

 TESTING THE NEEDS OF THE SOIL. 



Farmers generally imagine that they can have a chemical analysis of 

 their soil made, and thus find out what are its needs. Chemists have long 

 ago found out that a soil analysis will be of little use in determining the 

 needs of the soil for plant food. A soil may be entirely unproductive, and 

 yet chemical analysis may show that it has in it all the elements of fertility; 

 but they may be in such an insoluble form that plants cannot get them. 

 Many have, therefore, paid more attention to the chemical composition of the 

 different crops, and from these data have tried to compound fertilizers that 

 are especially adapted to each crop grown. WJiile this is an advance over the 

 soil analysis it is not really what the farmer needs to know in regard to his 

 particular soil. A certain crop may require plant food in a complete fer- 

 tilizer in certain proportions, and yet the farmer buying such a fertilizer may 

 be spending money needlessly if his soil is already sufficiently stocked with 

 any one of these constituents. 



Hence the only way to determine what the land needs is to experiment 

 on the land itself. Plants in their growth on the soil will tell you what the 

 chemist cannot tell. It will tell you what particular form of plant food it is 

 deficient in and which you have no need for buying. Farmers generally buy 

 fertilizers according to their commercial valuation, and while that may be 

 their true value on the market, the value of the article on their land may 

 be a very different thing, and they may be spending money for what they do 

 not need and be buying too little of what they especially need. The farmer 

 can find this out for himself, and no one else can tell him beforehand. The 

 needs of soils vary so greatly, even on the same farm, that true farm economy 

 indicates that the farmer must be himself an experimenter in order to dis- 

 cover what no Experiment Station can discover for him. But any of the 

 Experiment Stations in the various States will readily help the individual 

 farmers in their States in conducting these experiments. We would impress 



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