The Bulletin. 11 



FERTILIZING THE COTTON CROP. 



In the use and application of commercial fertilizers great care and 

 judgment should be exercised. The fertilizer bill is usually the 

 largest item of expense that enters into the production of the crop, 

 and since an insufficiency of any one of the elements of plant food 

 places the limit on the power of the soil to produce and renders value- 

 less, so far as the immediate crop is concerned, any over abundance 

 of the other plant food elements, due consideration should therefore 

 be given to the soil in respect to its deficiencies in the various elements 

 of plant food, in order that these elements may be purchased and 

 applied in quantities proportionate to the needs of the soil and re- 

 quirements of the crop. 



It may be well to consider how much of the plant food elements, 

 nitrogen, phosphoric acid and potash, are removed from the soil of an 

 acre of land, in the production of a crop of five hundred pounds of 

 lint cotton, that we may better understand the requirements of the 

 cotton plant, to produce a given amount. According to a summary 

 of experimental work with cotton by Mr. B. W. Kilgore, State 

 Chemist, thirty pounds of nitrogen, twelve pounds of phosphoric acid, 

 thirteen pounds of potash, are removed in the seed and lint (900 

 pounds seed and 500 pounds lint) and this does not vary greatly from 

 the average of several analyses, and may be assumed as approximately 

 correct. One and one-half pounds nitrogen, one-half pound phos- 

 phoric acid and two pounds of potash are removed in the lint. Twenty- 

 eight and one-half pounds of nitrogen, eleven and one-half pounds of 

 phosphoric acid and eleven pounds of potash are removed in the seed. 

 Sixty-seven and seven-tenths pounds of nitrogen, twenty-six and one- 

 half pounds of phosphoric acid, and fifty-nine and three-tenths pounds 

 of potash enter into the production of the stalks, leaves, burs, etc., 

 making a total of ninety-seven and seven-tenths pounds of nitrogen, 

 twenty-eight and one-half pounds of phosphoric acid, and seventy- 

 two and three-tenths pounds of potash removed from the soil by a 

 crop of this size. However, more than two-thirds of the nitrogen and 

 phosphoric acid, and nearly five-sixths of the potash are returned to 

 the soil in the stalks, leaves, burs, etc., and if the seed are returned 

 to the land on which they grew, and the lint only is sold, very little 

 fertility has been removed from the soil in the production of the 

 crop. And if the seed were exchanged for meal, at the present ratio 

 of exchange, pound for pound, or if they were sold and the proceeds 

 invested in fertilizers and these fertilizers applied -to the soil from 

 which the seed came, there would be a large balance of plant food 

 to the credit of the soil, and the five hundred pounds of lint would be 

 more than free, so far as depletion of soil fertility is concerned. It 

 is seen in the light of the foregoing facts that when only the lint is 



