THE HAGERSTOWN CLAY. 7 



refuse, the introduction of the terrace system of planting, and by 

 contour cultivation. It is also desirable that after the removal of an 

 intertilled crop, such as cotton or corn, some winter grain should be 

 sown upon the soil, in order that its vegetation and roots may prevent 

 the excessive erosion to which this soil is frequently subject during 

 the winter months. These methods would be sufficient to reclaim 

 thousands of acres which are now lying idle. 



Erosion not only results in a bodily removal of all of the surface 

 soil but also a considerable portion of the subsoil upon the more 

 steeply sloping areas. The less easily detected erosion which removes 

 a small proportion of the surface soil each year has frequently re- 

 duced the surface soil of the Hagerstown clay to a minimum depth of 

 2 or 3 inches. While this depth is maintained by the ordinary proc- 

 esses of cultivation, still there is annually a decided loss of fertile 

 surface soil through washing. In order that the surface soil of the 

 type may be deepened, made more friable and more retentive of mois- 

 ture, it is extremely desirable that the depth of plowing should be 

 gradually increased until an average depth of not less than 6 inches 

 is attained. This will form a permeable surface layer competent to 

 absorb a larger proportion of the annual precipitation and capable 

 of giving a better root hold to the growing crops. 



It is essential that the reincorporation of organic matter should 

 be practiced in conjunction with the deeper plowing of the type. 

 For this purpose, the growing of mixed grasses, clover and timothy, 

 as a part of the regular rotation upon the farm, and the turning 

 under of the sod for the growing of the intertilled crops, either corn 

 or cotton, in regular rotation is considered the best practice. In 

 areas where such a rotation is systematically practiced, very little 

 difficulty is found either with the exhaustion of organic matter in the 

 surface soil or with serious erosion, except upon the most steeply 

 sloping areas. Where it is not possible to maintain the organic mat- 

 ter content and texture of the surface soil in good condition through 

 the ordinary practices of crop rotation, it is extremely desirable that 

 some winter cover crop like winter wheat or winter rye should occa- 

 sionally be grown to be plowed under in the spring for the reincorpo- 

 ration of organic matter in the surface soil after the winter crop has 

 served its purpose of preventing serious erosion. Wherever it is pos- 

 sible the use of some leguminous cover crop like cowpeas, sown late 

 in the season, or soy beans, or even crimson clover, is to be^recom- 

 mended. The benefits to be derived from a leguminous crop are con- 

 siderably greater than from any of the small grains thus used. 



The systematic rotation of crops upon the Hagerstown clay is to 

 be recommended in all of the areas where it occurs. Corn or export 

 tobacco constitutes an excellent intertilled crop to be planted upon 

 freshly plowed sod. Either crop can well be followed by winter 



