10 SOILS OF THE EASTERN UNITED STATES. 



in Iowa winter wheat is one of the prominent small grain crops. 

 In all instances the acreage devoted to this crop is being decreased 

 annually, although the yields are fair, the average from year to year 

 ranging from 10 to 15 bushels per acre. The reason for this decrease 

 lies principally in the general adoption of a crop rotation, well suited 

 to the type, which includes the growing of corn, oats, and grass to the 

 exclusion of wheat. The superior value of this rotation in the main- 

 tenance of the crop-producing power of the soil has been well learned 

 by the farmers in these locations, with the result that wheat growing 

 has been subordinated to the other forms of general farming and to 

 the crops produced in the regular rotation for the feeding of beef 

 cattle and of dairy cows. In fact, the growing of wheat in these 

 locations is practically a survival of the early pioneer conditions 

 while the adoption of the regular rotation marks an advance in the 

 agricultural methods of these States. 



In southern Minnesota, particularly, and to a considerable degree 

 in eastern North Dakota the Carrington loam is known as an excel- 

 lent spring wheat soil. In fact, in the Marshall area, Minnesota, 

 comprising a portion of Lyon County, the Carrington loam taken as 

 a whole excels all other soil types of the area in the production of 

 spring wheat, not only because of the excellent yields, averaging 14 

 bushels per acre through a long period of years, but also because of 

 the superior quality of the wheat grown, making possible its sale for 

 milling purposes at prices above those usually received for wheat 

 grown upon other soil types. Similarly in North Dakota the Carring- 

 ton loam produces an excellent quality of spring wheat and the yield 

 per acre is dependent more upon the methods of tillage of the soil 

 and upon attendant circumstances of rainfall than upon the inherent 

 properties of the soil itself. This is markedly shown in the soil sur- 

 vey of the Jamestown area, North Dakota, where the yields of wheat 

 on the Carrington loam in the eastern portion of the area are nearly 

 double the yields secured upon the same type in the more western 

 portion of the same survey. This is due primarily to the decreasing 

 annual rainfall from the eastern to the western part of a single soil 

 survey area located along the line of critical precipitation so far as 

 wheat production is concerned. 



Thus the Carrington loam may be ranked as an important wheat- 

 growing soil, particularly in the more northern and northwestern 

 regions of its development. 



In the more southern and eastern sections, oats constitute tl 

 dominant small grain upon the Carrington loam, the acreage of thi 

 crop being second only to that devoted to corn. The yields of oat 

 in Indiana, Iowa, and Minnesota are uniformly high, averaging from 

 35 to 45 bushels per acre through long periods and attaining tl 

 high mark of 50 to 60 bushels per acre in favorable seasons uj 



