52 KNAPP METHOD OF GROWING COTTON 



This gives a total of 14 pounds of plant food 

 in a loo-pound sack. When a ton of such fertili- 

 zer is bought, the purchaser receives nitrogen, 

 40 pounds; water-soluble phosphoric acid, 160 

 pounds; citrate-soluble phosphoric acid, 40 

 pounds; potash 40 pounds. Notice that what 

 is called "available" is the sum of the water-sol- 

 uble and the citrate-soluble phosphoric acid. In 

 this fertilizer we get three things that are of use 

 2 pounds of nitrogen, 10 pounds of phosphoric 

 acid, and 2 pounds of potash to the 100 pounds. 



If cotton seed meal, acid phosphate, and kainit 

 are used to make this fertilizer, it will require the 

 following quantities for one ton of the mixture: 



TABLE I. PROPORTIONS AND VALUE OF COTTON SEED MEAL, 



ACID PHOSPHATE, AND KAINIT REQUIRED FOR A TON OF 

 FERTILIZER OF A 2-IO-2 COMPOSITION 



*The value of fertilizing materials is calculated on the basis of 

 20 cents a pound for nitrogen and 5 cents a pound each for phosphoric 

 acid and potash. 



