The Bulletin. 9 



I. FERTILIZER EXPERIMENTS WITH COTTON ON PIEDMONT 



RED CLAY LOAM SOIL 



This is the second of a series of Bulletins giving the results of 

 experiments to determine the fertilizer needs of different crops on 

 different type soils. The first report, issued as the June (1910) 

 Bulletin^ gave the ''Results of Fertilizer and Variety Experiments 

 with Cowpeas on Piedmont Red Clay Loam Soil." 



WORK REPORTED. 



Cotton is our leading money crop. More commercial fertilizer is 

 used in fertilizing and growing this crop than any other. It re- 

 sponds readily and profitably to proper fertilization. Some ten 

 years ago systematic experiments wei'e begun to determine the ferti- 

 lizer or plant-food requirements for the most economical production 

 of cotton on our different cotton soils. 



On the following pages are recorded the results of seven years' 

 fertilizer and variety tests of cotton on the Iredell Test Farm of this 

 Department, extending through the years 1903-1909, both inclusive. 

 The work is being continued to collect further data, when cotton is 

 grown as it has been in the work here recorded, as well as in rotations 

 with other staple crops and soil-improving crops. 



LOCATION OF FARM AND CHARACTER OF SOIL. 



The Iredell Test Farm is located near Statesville, in Iredell 

 County, well up in the Piedmont (foothill) section of the State, the 

 elevation being 950 feet above sea-level. The main type of soil on 

 the farm is red (cecil) clay loam, the subsoil being a moderately 

 heavy clay, but the surface soil has sufficient sand in it to make it a 

 clay loam rather than a clay, though when freshly plowed it would 

 to a casual observer be looked upon as red clay. The main types of 

 soil in the Piedmont are cecil sandy loam (gray land), red (cecil) 

 clay loam, and red (cecil) clay, the latter two being the predomi- 

 nating types. The clay and clay-loam types are rich in potash, very 

 poor in phosphoric acid, the amount of nitrogen depending on the 

 organic matter in the soil. Analyses of samples of soil from the 

 unfertilized plats, on which these experiments were conducted, show 

 that the soil contains about the following number of pounds of plant 

 food per acre (to a depth of ten inches, estimating the weight of this 

 ten-inch acre soil to be three million pounds) : 



Nitrogen (N ) 2,010 pounds. 



Phosphoric Acid (P2O5) 2,280 pounds. 



Potash (KoO) 12,540 pounds. 



Lime (CaO) 12,840 pounds. 



