92 FIELD CROPS FOR THE COTTON-SELT 



102. Home-mixing fertilizers. — The farmer who 

 makes a practice of purchasing ready-mixed fertiKzers 

 usually pays more for the plapt-foods secured than would 

 have been the case had he purchased the incomplete 

 materials and, mixed them at home. The most economical 

 use of fertiUzers is possible only when a fertilizer test is 

 made and the materials bought, mixed, and applied in 

 accordance with the needs of the soil as indicated by this 

 test. To assume that any particular brand of fertilizer 

 is imiversally best for cotton is also an assumption that 

 all cotton soils are alike as regards their fertilizer needs 

 — an assumption that is grossly absurd. 



103. Time of applying fertilizers. — Such fertilizing 

 materials as acid phosphate, cotton-seed meal, dried 

 blood, tankage, and the potash fertiUzers should be ap- 

 plied either a short while before or at the time of planting. 

 Phosphoric acid is readily fixed in the soil. There is little 

 danger from leaching as it becomes well distributed in the 

 soil and soon changes to insoluble forms. The organic ni- 

 trogenous fertilizers all have to be oxidized and converted 

 into nitrates before they are of value to the crop. Potash 

 is very quickly fixed in the soil by the double sihcates. 

 As a result of these properties of the above materials, 

 experiments have shown iio material gains from the prac- 

 tice of postponing the appUcation of the fertilizers until 

 the crop is up and growing. However, where very heavy 

 applications are to be made, better results are usually 

 secured by saving a part of the fertihzer for intercultural 

 applications. 



If nitrate of soda is to be used, it should be applied after 

 the plants have begun growth. 



104. Methods of applying fertilizers. — When fer- 

 tiUzers are applied to cotton in amounts less than 400 



