COMMERCIAL FERTILIZERS 109 



Nitrogen 1.65 units @ $4.00 $6.60 per ton 



Phosphoric acid (available) 8.00 units @ 1.20 9.60 per ton 



Phosphoric acid (insoluble) 8.00 units @ 0.40 3.20 per ton 



Potash 2.00 units @ 1.20 2.40 per ton 



Value $2 1. 80 per ton 



It will be seen that the delivered price of the fertilizer is 

 $2 1 .So per ton. These figures will not necessarily hold through- 

 out the United States, but they are representative and illustrate 

 the method of calculating fertilizer values. 



134. Home mixing of fertilizers. It is sometimes cheaper 

 for farmers to secure the raw materials and mix their own fer- 

 tilizers than it is to buy them ready mixed. Such a plan has 

 the further advantage of enabling the farmer the better to adapt 

 the fertilizer to the needs of the soil and the requirements of 

 the crop. For men who are well informed on the matter of 

 fertilizers and who use considerable quantities of such material, 

 home mixing is usually best. 



135. Methods of applying fertilizers. To obtain the best 

 results, fertilizers must be evenly distributed. This is usually 

 done by the use of a fertilizer drill or fertilizer scatterer. In 

 the case of intertilled crops, such as corn, there are devices 

 for distributing fertilizers in the row or hill. Fertilizers are 

 applied in amounts varying from 50 pounds to 1000 pounds 

 per acre, but from 150 to 400 pounds is a fair application for 

 general crops. 



136. Fertilizers for different crops. The soil, as well as the 

 crop, determines the kind and amount of fertilizer to apply. In 

 general, sandy soils are most in need of complete fertilizer, and 

 the dark clay-loam soils are usually in need of nitrogen and 

 phosphorus. On average loam soil which is only fairly fertile, 

 wheat will respond best to the application of a fertilizer contain- 

 ing considerable amounts of readily available phosphates, such 

 as acid phosphate, bone meal, or highly phosphatic mixed ferti- 

 lizer. A fair amount of nitrogen will also usually be profitable, and 

 a small amount of potash will improve the quality of the grain. 

 Corn responds to all three fertilizer elements (Fig. 46), and on 



