40 FIELD OPERATIONS OF THE BUREAU OF SOILS, 1919. 



The Epping silt loam is residual in origin, having weathered from 

 the underlying Brule clay formation. This is a slightly consoli- 

 dated, pale-pink to almost white clay, which gives the soil its light 

 colored floury character. 



The t^'pe is not extensive in the county. It occurs mostly on the 

 south slopes of the Pumpkin Creek Valley, the largest body lying 2 

 miles southeast of Harrisburg. A smaller area occupies a narrow 

 strip along the northern edge of the Eough broken land, about 4 

 miles southeast of Harrisburg. One of the most typical bodies lies 

 about 2 miles northeast of Bighorn Mountain. 



The topography of the type varies from steeply rolling to undulat- 

 ing, the greater part being gently rolling. It is roughest in the areas 

 adjacent to bodies of Eough broken land. In a few places patches 

 of Brule clay are badly eroded, giving locally a typical bad land 

 topography. Drainage is good and in places excessive. 



The Epping silt loam is unimportant agriculturally, and a very 

 small proportion of it is under cultivation. The land is mostly used 

 for grazing horses and beef cattle. 



The native vegetation consists of buffalo grass, grama grass, 

 blackroot, western wheat grass, and wire grass. On the cultivated 

 areas, wheat, rye, and oats are the principal crops. Spring wheat 

 is grown most extensively. The type is not as productive as most of 

 the table-land soils, on account of its lower organic matter content. 

 Wheat gives an average yield of about 12 bushels, rye 12 baishels, and 

 oats 20 bushels per acre. The land will support from 30 to 35 head 

 of cattle per section the year round, if hay is fed in severe weather. 



The soil is easy to handle on account of its loose, friable structure. 

 It has a tendency to clod when plowed wet, but the lumps are easily 

 reduced. No definite system of crop rotation is practiced and manure 

 is not ajDplied to the land. 



The selling price of the Epping silt loam ranges from $12 to $30 

 an acre, depending largely upon its topography. 



Epping silt loam.^ hasin phase. — There is a small body of Epping 

 silt loam, basin phase, in the vicinity of Harrisburg. which deserves 

 special mention, as it differs considerably from the typical material. 



The soil is a brown to grayish-brown, loose friable silt loam, 8 to 

 10 inches deep. It is high in organic matter, which gives the surface 

 a darker color than that of the main type. The upper subsoil differs 

 little either in color or texture from tlie surface material, but below 

 about 20 inches it becomes slightly lighter in color, being a light 

 grayish brown to gray floury silt. 



The underlying Brule clay formation is nowhere more than 4 feet 

 below the surface and is exposed in places along shallow road cuts. 



The surface of this phase is very flat. It occupies the lowest posi- 

 tion in the general basin surrounding Harrisburg. The type has 



