66 SOILS: PROPERTIES AND MANAGEMENT 



In the utilization of soil, climate, particularly as regards 

 rainfall and temperature, plays an important part. Crop 

 adaptation is really more of an adaptation to climate than 

 to soil, although the latter also should be very carefully 

 studied. The climatic relationships in soil formation, 

 in soil chemistry, and in geochemistry in general, cannot 

 be too strongly emphasized, whether the viewpoint be 

 technical, practical, or merely educational. 



52. Geochemical relationships of residual and marine 

 soils. — It is evident from the above that coastal plain, 

 residual, and glacial soils should exhibit certain well- 

 defined general differences due to their mode of formation. 

 The following analyses, which are representative of the 

 provinces in question, illustrate the chemical differences 

 of coastal plain and residual soils : — 



Analyses of Typical Coastal Plain and Rbsibual Soils 



SiOs 

 AI2O3 



P2O5 



CaO 



CO2 



MgO 



NazO 



K2O 



Light Sandy 

 Loam eeom 

 Maeyland 



AvijEage op 

 5 Samples 1 



CoKN AND 



Wheat Clay 

 Loam Soil 



Avbkage or 

 3 Samples 1 



Residual 

 Soil feom 



Virginia 

 Gneiss 2 



92.30 



80.55 



45.31 



3.20 



8.82 



26.55 



.91 



2.67 



12.18 



.05 



.42 



.47 



.41 



.47 



trace 



.08 



.05 



trace 



.35 



.29 



.40 



.50 



.49 



.22 



.70 



1.22 



1.10 



Residual 



Soil feom 



Virginia 



Limestone ^ 



57.57 



20.44 



7.93 



.10 



.51 



.38 



1.20 



.23 



4.91 



^VeiteL., F. P. The Chemical Composition of Maryland 

 Soils, Maryland Agr. Exp. Sta., Bui. 70, pp. 71 and 73. 1901. 



2 Merrill, G. P. Weathering of Micaceous Gneiss in Albemarle 

 County, Virginia. Bui. Geol. See. Amer., Vol. 8, p. 160. 1879. 



3 Diller, G. S. The Educational Series of Rock Specimens. 

 U. S. Geol. Survey, Bui. 150, p. 385. 1898. 



