I. FERTILIZER EXPERIMENTS WITH CORN ON PIEDMONT RED 



CLAY LOAM SOIL 



AND 



M. VARIETIES, CULTURE, AND FERTILIZATION OF CORN ON 

 PIEDMONT RED CLAY LOAM, RED CLAY, AND VALLEY 

 SOILS. 



Being a Report of Work with Corn on the Iredell Test Farm in 1903-'09 



Inclusive. 



By B. W. Kilqore, C B. Williams, G. M. MaoNider, and F. T. Meacham. 



GENERAL SUMMARY OF RESULTS OF FERTILIZER TESTS. 



1. The right fertilization of corn has paid well on the red (cecil) 

 clay loam soils of 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 corn on this land nitrogen alone was 

 used at a loss ; potash alone was used at a loss ; and from nitrogen 

 and potash combined with each other the increased yields over un- 

 fertilized plats were very small and were not sufficient to cover the 

 cost of fertilizer, the fertilizer application from these two con- 

 stituents having cost $1.2G per acre more annually than the value 

 of the increased yield of corn. This shows that neither nitrogen 

 alone, potash alone, nor nitrogen and potash combined with each 

 other should be used on this land in growing corn. 



3. Phosphoric acid alone produced increased yields at good prof- 

 its in all cases. ISI^itrogen combined with phosphoric acid added de- 

 cidedly to the increased yields and profits, as did potash also when 

 combined with phosphoric acid, though larger yields were obtained 

 from nitrogen and phosphoric acid than from potash and phosphoric 

 acid, indicating that nitrogen is more important than potash for corn 

 production on this soil. Nitrogen, phosphoric acid and potash com- 

 bined in a complete fertilizer gave slightly larger yields, but no 

 larger profits than nitrogen and phosphoric acid and potash and 

 phosphoric acid. 



The experiments, as a w^hole, show that phosphoric acid is the pre- 

 dominant fertilizer constituent for increasing yields and adding to 

 profits in growing corn on this soil and that nitrogen is the next most 

 important constituent. 



