164 THE SOILS OF PEIJSTCE GEORGE^S COUS^TY 



other regions have proved valuable for the production of grapes, but 

 reforestation is recommended for the majority of the areas found in 

 Prince George's County. 



THE EEONARDTOWN LOAM. 



The LeonardtoAvn loam comprises a total area of about 70 square 

 miles. It lies entirely within the upland portion of the county, occu- 

 pying the highest levels in the southern part of the county and cover- 

 ing the gentle slopes along the border of the Piedmont Plateau. In 

 the southern part of the county the surface of this soil type is flat or 

 only gently rolling, while in the northern part it occurs somewhat less 

 typically developed as a rolling or sloping surface. In all cases this 

 soil type is bordered by areas of stony or gravelly soil. In other por- 

 tions of the Coastal Plain this soil was originally occupied by exten- 

 sive forests of white oak. When this timber is removed the areas 

 occupied by the Leonardtown loam usually grow up to pitch pine 

 unless cultivated. A considerable portion of this soil type in the 

 southern part of Prince George's County is still covered by white- 

 oak forest, but in the northern part of the county it is almost entirely 

 under cultivation. 



The soil itself consists of a yellow silty loam having an average 

 depth of about 10 inches. It is underlain by a heavier yellow loam, 

 which usually grades into a mottled loam at a depth of from 28 to 32 

 inches. At this depth the subsoil becomes brittle and crumbly, and 

 a close examination shows that it consists of thin layers or lenses of 

 clayey loam, which are separated from one another by thin seams 

 or pockets of sand. Where the entire thickness of the soil formation 

 does not exceed 5 or 6 feet the subsoil may also contain some fine 

 gravel. Along the borders of this soil type the sand and gravel 

 become more prominent as the soil becomes thinner, and the Leonard- 

 town loam grades off into more stony or gravelly types. The entire 

 area of the Leonardtown loam is underlain at varying depths by a 

 bed of coarse gravel mingled with sand, which reaches the surface 

 along the margins of stream valleys. This gravel and sand give rise 

 to another type of soil, elsewhere described, and also play an impor- 

 tant part in the natural underdrainage of the Leonardtown loam. 



