The Bulletin 



41 



The rate of application is based on the amounts of phosphoric acid, 

 nitrogen and potash known to be removed by maximum yields. This 

 may seem high to some but many such yields are yearly obtained in the 

 State and over tAvice this amount has been produced on a measured 

 acre. Ea'cu on these more or less depleted soils, a yield of nearly 80 

 bushels per acre on Charlotte field No. 2 has been obtained by the use 

 of commercial fertilizers alone. In order to secure the required amount 

 of plant food, it was necessary to apply tbe following amounts of ma- 

 terials for corn : 



13 per cent dried blood — 1,138 pounds. 

 16 per cent acid phosphate — 331 pounds. 

 50 per cent sulphate of potash — 170 pounds. 



In calculating for maximum yields of corn, wheat, oats, cotton and 

 red clover the following figures were used in determining the applica- 

 tions of blood, acid phosphate and manure salt required per acre: 



•Applied only 40 lbs. N., assuming that two-thirds of it was taken from atmosphere. 



Lime was applied at the rate of 1,000 pounds of rock lime per acre 

 annually, except in 1912 and 1914 it was left off of the Gastonia, Iredell 

 Field E, and the two Charlotte fields. On the soil type fields, the fer- 

 tilizing materials were always carefully weighed out each year and ap- 

 plied uniformly broadcast over the plats. As soon as applied they were 

 immediately harrowed or disked in and seeding of the crop made. 



ANALYSES OF SOILS OF EXPERIMENTAL FIELDS. 



Below will be found the amounts of nitrogen, phosphoric acid, potash 

 and lime in the top and in the subsoil of the soil of each of the experi- 

 mental fields. The top soil is calculated as weighing 2,000,000 pounds 

 per acre to the depth of 6^^ inches ; and the subsoil as weighing 8,000,- 

 000 pounds to a depth of 28 inches beneath the top soil. From the 

 chemical analyses the calculations are made of the number of pounds of 

 each of the plant food constituents contained in top and subsoil of each 

 field. 



