ANALYSIS BY THE UNITED STATES BUREAU 137 



They have suffered from decomposition and solution more than have the 

 Piedmont and Appalachian soils, and there has often been a greater .separation 

 of the finer from the coarser particles. " 



"The tables show that the residual soils, Chester mica loam, Porter's black 

 loam, and Cecil clay, contain more plant-food constituents than do the Coastal 

 Plains soils. This is especially true of the phosphorus, the potassium, and the 

 magnesium." 



"The sandy and the silty glacial soils are somewhat similar in percentage 

 composition. Owing to the latter consisting to so large an extent of such fine 

 particles, it might have been supposed that decomposition and leaching would 

 have affected them more . . . but the silty soils are loessial for the most part, 

 and were formed from material blown by winds from glaciated areas and 

 deposited where now found, or of material that has since been reworked by 

 water. Minerals rich in alkalis and alkaline earths, being relatively easily 

 crushed, would form a larger percentage of these silty soils than they do of the 

 original glacial soils ; so that even if there has been a tendency to impoverish 

 them by leaching, their originally greater richness enables the loessial soils 

 to compare well with those strictly glacial." 



In Table 22 are reported the total amounts of phosphorus, po- 

 tassium, magnesium, and calcium found by the Bureau of Soils in 

 2 million pounds of ignited soil for the surface soil of each of the 

 27 type soils, and also the amounts in the acid-soluble portion of 

 one subsoil, or underlying greensand marl. 



While these soils " were selected to represent all classes those 

 of low, of medium, and of high productivity," Bulletin 54 gives no 

 information as to the agricultural value of the different soils. 

 Fortunately, the Annual Reports of the Bureau of Soils contain the 

 descriptions made by the soil survey men concerning the common 

 crops and normal crop yields produced on each of these soils, and 

 thus a correlation is made possible between chemical composition 

 (as recently determined by actual ultimate analysis) and produc- 

 tive capacity, of these important and extensive types of soil (as 

 reported in previous years from field investigations). Even here 

 the student is advised not to accept opinions expressed, predictions 

 made, or conclusions drawn, unless clearly supported by chemical 

 facts or by long-continued agricultural experience. 



In each of the following descriptions the first paragraph is quoted 

 from Bureau of Soils Bulletin 54 (December, 1908), and the 

 second paragraph is quoted from the Annual Report of the " Field 



