10 SOILS OF THE EASTERN UNITED STATES. 



areas the native prairie grasses are allowed to remain upon the type 

 to furnish excellent grazing for herds of beef cattle. 



The gentle slopes of the surface, the stone free condition of the 

 soil, its considerable depth, its adequate supply of organic matter, and 

 its excellent texture and structure, rendering tillage operations 

 easy, have led to this complete and efficient usage of the Marshall 

 silt loam. 



The adoption of improved cultural methods within the dry farming 

 areas of central Kansas and Nebraska has constituted the only wide 

 extension of occupation which the Marshall silt loam has experienced 

 during the past 40 or 50 years. Under these improved cultural 

 methods, all of which tend toward the absorption and retention of 

 atmospheric moisture for the use of plants, areas previously con- 

 sidered too dry for the production of crops are now rapidly being 

 utilized for the production of sorghum, Kafir corn, broom corn, 

 millet, emmer, alfalfa, and durum wheat. Under this occupation the 

 last areas of native pasture grasses devoted to the ranging of cattle 

 are disappearing. 



CROP ADAPTATIONS. 



The Marshall silt loam is the great, dominant, Indian corn-producing 

 soil of the central prairie States. Throughout the region where it 

 occurs from central Indiana to central Kansas and Nebraska the 

 yields of this crop reported from the Marshall silt loam are not only 

 above the yields reported from associated soil types, but they are so 

 high that the counties principally covered by the Marshall silt loam 

 are the premier corn counties of these States. In such counties as 

 have been included in the soil surveys, where 50 per cent or more of 

 the total extent of the county consists of this type the average yields 

 of corn per acre, as ascertained from the census reports, range from 

 25 to 35 per cent above the average yields for the States in which 

 such counties occur. In Indiana, Illinois, northern Missouri, and 

 southern Iowa the yields of corn per acre in counties dominated by 

 this type range from an average of 37 bushels to an average of 49 

 bushels per acre. Similarly in eastern Kansas and Nebraska where 

 the rainfall is adequate for maturing large yields of Indian corn, the 

 average yields of this crop in counties dominated by the Marshall silt 

 loam range from 35 to 40 bushels per acre. Even in more western 

 counties, where the rainfall is supposed, popularly, to be inadequate for 

 corn production, yields of 25 to 30 bushels per acre are secured. In 

 all cases it may be asserted without fear of contradiction that the corn 

 yields upon the Marshall silt loam throughout its extent exceed the 

 yields secured upon any other single extensive soil type. In fact a 

 large proportion of the annual corn supply of the United States is 

 secured from States and counties where corn production is principally 

 developed upon this soil. 



