MAKING THE SOIL PRODUCE CROPS 



them all into a mixture. Home mixing will not 

 be found profitable where small amounts of 

 fertilizer are used. Those who practice home 

 mixing for the first time should realize that most 

 combinations of ingredients will "set" or harden 

 if not used immediately, necessitating the break- 

 ing up and pulverizing of the mass. When 

 it is broken up after curing, no further diffi- 

 culty should be experienced with "setting" if 

 the mixture is kept in a dry place. The advan- 

 tages of home mixing for the large user lie in 

 lower cost per ton of plant food as a rule; 

 confidence in the quality of the ingredients which 

 he should purchase on the basis of guaranteed 

 analysis; and the setting up of a mixture which 

 study of his soil and the plant requirements has 

 convinced him is best suited for his individual case. 

 Chemical Soil Analysis Not Helpful. There is 

 a mistaken notion that it is necessary to analyze 

 soils chemically in order to fertilize them 

 intelligently. Such an analysis of a reasonably 

 fertile soil will show the presence of the essential 

 elements of plant food, though perhaps not 

 all in sufficient amounts, to produce ordinary 

 crops for centuries to come. Only a small 

 amount of the elements become available for 

 root absorption each year and a chemical 

 analysis will not bring out this most important 

 factor availability. The use of a few simple 



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