224 COTTON CULTURE 



of potash are kainit, muriate and sulfate of potash. Muriate of 

 potash will usually furnish the potash element more cheaply than it 

 can he purchased in either sulfate of potash or kainit. 



Lime. Lime, when used alone, has little or no effect on the 

 growth of cotton, unless the soil is in a very poor physical condition 

 and has a specific need for this material. However, when it is 

 applied with a complete fertilizer the action of lime in rendering 

 more available the other constituents may at times make profitable 

 its use. 



Combination of Fertilizers. The cotton plant requires a bal- 

 anced food. Hence the fertilizing elements are more efficient when 

 combined in a complete fertilizer ; that is, one containing balanced 

 proportions of nitrogen, phosphoric acid, and potash. Of these 

 elements, phosphoric acid is the most important and controls the 

 effectiveness of the others. 



Proportions of the Fertilizing Elements. In the total amount 

 of fertilizer the relative proportions which should be used of phos- 

 phoric acid, nitrogen, and potash, vary according to the needs of the 

 soil. However, the usual proportions of these elements, in a com- 

 plete fertilizer for cotton, are approximately, phosphoric acid 2y 2 , 

 nitrogen 1, potash y 2 . 



Amount of Fertilizer. The amount of fertilizer which may 

 profitably be applied to cotton depends chiefly upon the character 

 and previous treatment of the soil, and to some extent upon the 

 season. On soils of an average fertility, 400 to 600 pounds of a 

 complete fertilizer is usually the most profitable amount, but to 

 include soils of all classes the limits of the application may at times 

 range from 200 to 1000 pounds. 



Method of Applying Fertilizer. The general results of experi- 

 ments in the methods of applying fertilizers to cotton show clearly 

 that drilling is far more efficient than broadcasting, especially if 

 small amounts of fertilizer are used. Fertilizers are drilled either 

 by hand, using for the purpose a long funnel or "guano horn," or by 

 a fertilizer distributor, which drills and covers the material in a 

 single operation. They are usually distributed at a depth of 3 to 4 

 inches below the surface of the soil. 



