I. FERTILIZER EXPERIMENTS WITH COTTON ON PIEDMONT 



RED CLAY LOAM SOIL 



AND 



II. VARIETIES, CULTURE, AND FERTILIZATION OF COTTON 



ON PIEDMONT RED CLAY LOAM, RED CLAY, AND VAL- 

 LEY SOILS. 



Being a Report of Work with Cotton on the Iredell Test Farm 



IN 1903-'09, Inclusive. 



By B. W. Kilgore, C. B. Williams, G. M. MacNider, and F. T. Meacham. 



GENERAL SUMMARY OF RESULTS OF FERTILIZER TESTS. 



1. The proper fertilization of cotton pays large profits, larger ones 

 than any other staple crop generally grown in the State. What this 

 fertilization should be on this and similar soils is shown by the results 

 of our experiments as given on the following pages. 



2. For the production of cotton on this land nitrogen alone was used 

 at a loss ; potash alone gave small increase in yields and profits ; potash 

 and nitrogen combined were less effective than potash alone, indicat- 

 ing that potash is more important than nitrogen, though neither is 

 very effective, and should not be used alone or combined for cotton 

 on this soil. 



3. Phosphoric acid alone produced decidedly increased yields at 

 good profits in all cases. Nitrogen combined with phosphoric acid 

 did not increase the yields very much over phosphoric acid alone, 

 while potash added to phosphoric acid produced profitable results. 

 Nitrogen, phosphoric acid, and potash combined in a complete ferti- 

 lizer yielded larger returns and profits than either one of th*e three 

 constituents or two of them combined, the indications being that 

 practically two-thirds of the increased yields and profits were the 

 result of phosphoric acid, and one-third of potash and nitrogen to- 

 gether, potash being rather more important than nitrogen. 



The experiments as a whole show that phosphoric acid is the pre- 

 dominant or controlling constituent for increasing yields and adding 

 to profits in growing cotton on this soil. 



