

LETTERS OF SUMITTAL 





WASIIIXGTOX, D. C., June 20, 1904. 



SIR: In order to test, in an adequate manner, the field 

 methods which had been, devised for the determination of sol- 

 uble salts in soils, and in order to be able to study the same 

 soil under conditions where the yields were certain to be meas- 

 urably different, it was decided to develop systematic differ- 

 ences in each of the eight soils, chosen for the investigations of 

 1903, by the application of definite quantities of manure in 

 multiple amounts upon different portions of the areas where 

 crops were to be grown. 



Manure was chosen to develop these differences because it is 

 acknowledged to be the best general fertilizer known, and be- 

 cause it is a universal by-product of the farm whose most eco- 

 nomical use demands much fuller knowledge than is yet avail- 

 able. The quantities of manure chosen, were small 5, 10, and 

 15 tons per acre in order better to test the sensitiveness and 

 reliability of the methods, by not developing too large differ- 

 ences ini the soluble salt content of the soil, and in order to gain 

 more definite knowledge of the relative and absolute efficiencies 

 of manure when applied broadcast to soil in different amounts. 



The results herewith submitted are those which relate to the 

 influence of different amounts of manure upon the water-soluble 

 salts 1 which may be recovered from: soils with distilled water; 

 and those which show the absolute and relative efficiencies, the 

 first season, of different amounts of manure when applied 

 broadcast to soils and well plowed under. 



The fitting 1 of the soils, application of manure, planting and 

 general care of the crops, were under the immediate charge of 

 W. O. Palmier, J. W. Xelson, J. O. Belz and A. H, Snyder; 



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