THE CARRINGTON LOAM. 9 



and has established an excellent reputation for itself for the produc- 

 tion of corn, wheat, oats, and the tame grasses in all areas where it 

 occurs. Increased occupation of the Carrington loam must, there- 

 fore, take the form of more intensive farming rather than of an 

 extension of tilled area upon the type. 



CROP ADAPTATIONS. 



Since the Carrington loam is distributed over a considerable ex- 

 tent of territory and occurs under varying conditions of altitude, lati- 

 tude, and of mean annual rainfall, there is quite a variation in the 

 adaptation of the type to crops. Thus in the region of southern 

 Michigan and northern Indiana, where it has been extensively 

 mapped, and also in central and northern Iowa corn constitutes the 

 dominant crop upon the Carrington loam, while in Minnesota and in 

 North Dakota spring wheat dominates all other crops. Winter 

 wheat is also grown extensively in Indiana, in conjunction with the 

 production of oats. 



The Carrington loam under proper conditions of rainfall and with 

 a growing season sufficiently long may be considered an excellent 

 soil for the production of corn. The yields secured in Michigan, 

 Indiana, and Iowa average from 35 to 45 bushels per acre over ex- 

 tensive areas, with frequent yields in excess of 50 bushels per acre. 

 Even in southern Minnesota, where the production of spring wheat 

 has long dominated the agriculture of the section, the acreage of 

 corn is being gradually increased, and the yields secured are very 

 satisfactory. They average from 30 to 35 bushels per acre, and with 

 the best methods of farming, including the use of stable manures 

 and the adoption of a definite rotation, these yields may be in- 

 creased. In North Dakota the production of corn is entirely sub- 

 ordinate to that of the growing of spring wheat, although certain 

 early maturing varieties may be grown to advantage, and even the 

 longer growing varieties may be produced as a silage crop for feed- 

 ing to dairy cows. Although the Carrington loam is not a great, 

 dominant corn soil like the Marshall silt loam, it ranks high both in 

 the acreage planted each year and in the yields per acre. While it is 

 thus secondary as a corn producing soil among those of the central 

 prairie States, it still holds an important place in the production of 

 this crop wherever the conditions of rainfall and of length of grow- 

 ing season are favorable. In fact, the Carrington loam is subordinate 

 only to the Marshall silt loam and to the Carrington black clay loam 

 as a corn soil. 



The variation in climatic conditions attendant upon the broad 

 extent of the Carrington loam shows its most striking influence, pos- 

 sibly, upon the crop adaptations of the type in the case of wheat 

 production. Thus in southern Michigan, in Indiana, and to a degree 



