6 SOILS OF THE EASTERN UNITED STATES. 



Erosion is not a problem in connection with the tillage of this type. 



Locally and particularly upon the morainal ridges to be found 

 within the area of the Carrington loam there are accumulations of 

 bowlders and of smaller stone, which it is necessary to remove before 

 the total area of the type may be subjected to cultivation. In such 

 instances the bowlders are usually removed and used for the construc- 

 tion of the foundations of buildings and the erection of stone fences 

 or. in extreme cases, where the presence of bowlders occurs in connec- 

 tion with the knobs and ridges of the higher moraine, such portions 

 of the type are occupied for grazing purposes only, while the more 

 level and the more nearly stone-free portions of the type are used for 

 tillage. 



In the more southern and eastern regions where the Carrington 

 loam is developed, particularly in the vicinity of Lake Michigan and 

 in north-central Iowa, there is abundant rainfall for the production 

 of all of the usual general farming crops. The temperatures during 

 the growing season are also such that corn may be grown to maturity, 

 while in Indiana and Michigan the climatic conditions induce the 

 production of winter wheat as contrasted with the spring wheat 

 which is grown chiefly upon this type from Iowa westward. In its 

 extreme western development in Nebraska and North Dakota the 

 rainfall is sometimes insufficient to produce fair average yields of 

 ordinary varieties of wheat, and recourse is had to the production of 

 the durum wheat and of emmer in place of winter or spring wheat. 

 Usually, however, through any long period of years the rainfall is 

 adequate for wheat production, and fair yields are obtained whei 

 any attempt is made at crop rotation and the proper care of the soil. 



IMPROVEMENT IN SOIL EFFICIENCY. 



The Carrington loam has been occupied in Indiana and in Michi- 

 gan for agricultural purposes for 60 years or more; in Iowa, for 

 period of 40 to 50 years; in Minnesota, for about 40 years; and ii 

 North Dakota, for only about 30 years. In the older settled regioi 

 the early stages of pioneer farming have passed, and the agricultui 

 has settled down to the usual practices of established farming. Ii 

 such regions crop rotations for the type have been worked out am 

 have usually become prevalent. Some care is taken with regard t( 

 the feeding of the produce of this soil to live stock upon the fai 

 where it occurs, and the stable manures are usually saved and appliec 

 to the land. In these instances the early crop yields of the pioneer 

 days, which were slightly decreased under the continued productioi 

 of corn and wheat for a considerable number of years, have beei 

 restored by the adoption of crop rotation in conjunction with some 

 form of animal husbandry and with the restoration of organic manui 

 to the soil. In the more northern and western sections, where the 



