24 SOILS AND FERTILIZERS 



the largest area of alluvial soil found anywhere in the United 

 States. Rivers flowing through the coastal plain are all 

 well lined with alluvial soil adjacent to their banks. 



24. Marine soils. — Soils of this formation have been 

 made by material carried by rivers and deposited in the 

 ocean, whence they afterwards emerged by elevation of the 

 sea bottom. They, therefore, resemble alluvial soil that 

 has been worked and reworked by sea water. They are 

 generally sandy soils, as the solvent action of water and the 

 pulverizing force of waves has disposed of most of the min- 

 erals except quartz. They are light not only in texture, but 

 also in color. They are nearly always deficient in organic 

 matter. Their sandy nature fits them particularly well for 

 trucking, and it is to that industry that a large area of 

 marine soil is devoted. 



25. Distribution of marine soils. — A fringe of land aver- 

 aging many miles in width along the Atlantic coast from 

 Long Island southward and including all of Florida is com- 

 posed of marine soil. This fringe then turns westward 

 and extends along the Gulf coast in a wide band as far west 

 as the Rio Grande. The alluvial plain of the Mississippi 

 river cuts through the belt, but at this point the marine 

 soil extends as far north as Tennessee. In the aggregate 

 the marine soils constitute a large area of important 

 agricultural land producing cotton, corn and other farm 

 crops, as well as truck crops for which they are especially 

 adapted. 



The following is a statement of the analysis of a typical 

 marine soil from the coastal plain in Maryland : 



Table 5. — Percentage Composition of a Typical Marine 



Soil 



Phosphoric acid . . . 0.05 Magnesia 0.35 



Potash 0.70 Iron 0.91 



Lime . 0.41 Silica 92.30 



