162 THE SOILS OF PRINCE GEOBGe's COUNTY 



soils, and are more typically developed. The areas along the stream 

 slopes, being subject to wash from above and also themselves arising 

 from local soil creep and migration, are more irregular in texture and 

 are usually of a less depth. 



The Windsor sand also occurs along the Patuxent River and some 

 of the other larger streams as a low-lying flat-topped stream terrace. 

 The soil texture is the same as that of the upland areas, and the vege- 

 tation and crop value are closely similar, but the position near tide 

 level gives an advantage to the areas in two ways. In the first place, 

 the products of the area are nearer to water transportation. In the 

 second place, many of the areas are so situated that whenever it 

 becomes desirable the waters of upland streams can be turned upon 

 them for irrigation purposes. 



The Windsor sand produces a good grade of tobacco in several 

 regions where it occurs, but it is uncertain, from the fact that its 

 loose, porous character makes it particularly hard to manage during a 

 protracted drought. The same difficulty is encountered in the pro- 

 duction of truck crops. For this reason an intensive system of culti- 

 vation is required, including the incorporation of considerable 

 amounts of organic matter with the soil to form a spongy, moisture- 

 holding mass, as well as to furnish needed plant foods. When, in 

 addition, it is possible to irrigate, and the value of crops produced is 

 sufficient to warrant it, the Avater supply can be controlled and a crop 

 produced every year instead of once in two or three years. As yet the 

 conditions are not such as would warrant so expensive a treatment in 

 the Prince George's areas, but many of them can be irrigated when it 

 becomes desirable to do so. 



The texture of this soil and subsoil is shown by the accompanying 

 table. 



THE SUSQUEHANNA GRAVEL. 



Scattered areas and long, narrow bands of distinctly stony or 

 gravelly soil have been indicated as a special type. The different 

 areas are usually found along steeply inclined slopes or near stream 

 divides. In both cases active stream erosion has removed the surface 



