8 SOILS OF THE EASTERN UNITED STATES. 



lar adaptation of the Hagerstown loam to the production of Kentucky 

 bluegrass predispose the areas of this type toward a natural grass 

 covering. This peculiarity everywhere tends to minimize the difficul- 

 ties experienced with erosion. 



In general there is a satisfactory amount of organic matter in the 

 surface soils of the Hagerstown loam. Wherever this supply has been 

 depleted by the long-continued cultivation of intertilled crops, the 

 restoration of organic matter is easily possible through the production 

 of cowpeas, of which the roots and stubble should be incorporated in 

 the soil, or through the laying down of the soil to grass and the plowing 

 in of the sod at the end of two or three years' time. Little difficulty 

 is experienced in maintaining the organic supply of the surface soil 

 where these practices are in vogue. 



Although in certain regions the Hagerstown loam has been culti- 

 vated for a period of more than 150 years with practically no appli- 

 cations of any mineral fertilizers and without any diminution of 

 crop yield, yet the application of organic manures and particularly 

 of large quantities of burned stone lime have been general through 

 the best tilled and most fertile localities where this type is found. 

 In more recent years also the application of mineral fertilizers, par- 

 ticularly in connection with the growing of the small grain crops, 

 has become more general. The fertilizers thus applied are usually 

 complete commercial mixtures with a large content of phosphoric 

 acid and only moderate percentages of potash and of nitrogen. 

 Satisfactory increases in the yield of wheat from such applications 

 are generally reported, whether the source of phosphoric acid has 

 been the phosphate rock, bone meal, or other organic source. 



One of the peculiarities of soil treatment upon the Hagerstown 

 loam, particularly in the Pennsylvania and Maryland areas where it 

 occurs, has been that of heavy applications of lime at least once in 

 the five-year rotation commonly practiced upon this soil type. 

 Although the Hagerstown loam is directly derived from limestone 

 rock, the method of its derivation is such, through the solution of 

 the lime carbonate, that the noncalcareous impurities in the rock 

 constitute the greater part of the residue which remains to form the 

 soil and subsoil. Thus, though the soils of the Hagerstown series, 

 including the Hagerstown loam, are limestone soils, they are not 

 necessarily calcareous soils. At the same tune lime rock is present 

 at little depth upon practically all farms where this soil occurs and 

 upon the majority of such farms there are outcroppings and ledges 

 of the rock. Even the early settlers in southeastern Pennsylvania 

 soon learned to burn this rock lime in their own kilns, using timber 

 cut upon the farm for firewood. The practice of using this burned 

 stone lime upon the soils of the Hagerstown series began during the 

 period of the Revolutionary War and has been conducted uninter- 



