oct.i4,i9i8 Fertilizer Potash Residues in Hagerstown Silty Loam 8i 



second year after the application show a greater potash excess than those 

 to which the potash fertiUzer is directly applied. 



(6) On crediting the fertilizer potash with the excess only of the 

 potash in the crops from the fertilized soil, the crops have used not more 

 than one-fourth of the potash dressings applied, leaving a residue of 

 1,300 to 1,400 pounds of fertilizer potash to be otherwise accounted for. 

 The higher solubility in weak solvents of the potash in the fertilized 

 soil accounts for enough of this residue to correspond to crop requirements 

 through a few years. The larger amount of potash dissolved from the 

 fertilized soil by strong, hot acid accounts for practically the entire 

 residue, but the close correspondence in potash quantities here observed 

 is doubtless an accident due to the particular conditions of temperature 

 and duration of solvent action maintained. 



(7) Taken as a whole, the conclusion is warranted that much of the 

 potash applied as fertilizer remains in the surface soil in a state highly 

 available to crops; that most of it remains there in a condition of lower 

 availability, and that the losses by drainage have probably not been great. 



LITERATURE CITED 

 (i) Brown, B. E., and Skinner, J. J. 



1908. AN INVESTIGATION OF THE CAUSES OF VARIATION IN SOn. FERTILITY AS 

 AFFECTED BY LONG-CONTINUED USE OP DIFFERENT FERTILIZERS. In 

 Penn. Agr. Exp. Sta. Ann. Rpt. 1907/08, p. 26-68, 4 fig. 



(2) CoLLiNSON, S. E., and Walker, S. S. 



igi6. LOSS OF FERTILIZERS BY LEACHING. Fla. Agr. Exp. Sta. Bui. 132, 20 p., 



5%- 



(3) Dyer, Bernard. 



1894. ON THE ANALYTICAL DETERMINATION OF PROBABLY AVAILABLE " MINERAL*' 



PLANT FOOD IN SOILS. In Jour. Chem. Soc. [London], v. 65, p. 115-167. 



(4) FrEar, William, and White, J. W. 



1910. A STUDY UPON A LOWER SILURIAN LIMESTONE SOIL. In Penn. Agr. Exp. 

 Sta. Ann. Rpt. 1909/10, p. 163-235, i pL 



(5) Gilbert, Henry. 



1894. DISCUSSION [of paper BY BERNARD DYER — ON THE ANALYTICAL DETERMI- 

 NATION OF PROBABLY AVAILABLE " MINERAL" PLANT FOOD IN SOILS]. 



In Proc. Chem. Soc. [London], v. 10, no. 134, p. 37-48. 



(6) HiLGARD, E. W. 



1906. SOILS . . . 593 p., illus. New York, London. 



(7) King, F. H. textbook op the physics op agriculture . . . ed. 2, 604 p. 



Madison, Wis. 



(8) PingreE, M. H. 



1906. THE influence of nitrogenous, phosphatic, and potassic fertilizers 



UPON THE percentage OP NITROGEN AND MINERAL CONSTITUENTS OF 



THE OAT PLANT. In Pcnn. Agr. Exp. Sta. Ann. Rpt. 1905/06, p. 43~S3- 



(9) Washington, H. S. 



1904. MANUAL OP THE CHEMICAL analysis OF ROCKS, cd. 1,183 p. NcW York. 



