4 SOILS OP THE EASTERN UNITED STATES. 



SURFACE FEATURES AND DRAINAGE. 



The greater portion of the Carrington silt loam occupies the un- 

 dulating to rolling prairie country lying between the main drainage 

 ways of the upper Mississippi Valley. It is found at altitudes rang- 

 ing from 750 feet to 1,100 feet in the more eastern areas of its oc- 

 currence, and from 1,000 feet to 1,300 feet above sea level in the 

 Northwestern States. In surface configuration it ranges from low 

 ridges and undulating plains to nearly level stretches of prairie 

 country. In any small area of the type the extreme variations in 

 elevation are inconsiderable and its total range in altitude is due to 

 its deposition over the varied surface of the low plateau of the upper 

 Mississippi Valley. 



The natural drainage of the Carrington silt loam is good over all 

 of the more rolling portions of its area. Within the more level tracts 

 natural drainage has frequently been supplemented by the installa- 

 tion of tile drainage and the areas thus reclaimed have become very 

 productive portions of the type. Only a small percentage of the 

 total area of this soil has required such treatment. Local depressions 

 and extremely, level tracts may still be improved by further attention 

 to this feature. In such areas the surface silty loam is frequently 

 darker, more waxy, and less easily tilled than the typical upland 

 occurrences of the type. 



Erosion does not constitute a serious problem in any areas except 

 along the immediate banks of deep-cut streams draining this soil. 

 Such areas are most frequently pastured or, in the eastern timbered 

 areas, maintained as a farm wood lot, so that the main body of the 

 Carrington silt loam is not subject to losses from this source. 



LIMITATIONS IN USE. 



The Carrington silt loam is sufficiently loamy and coherent to be 

 best suited to the production of the grains and grasses. Only where 

 the type departs from its normal characteristics is it particularly 

 adapted to special crops. In depressed areas where there has been 

 an unusual accumulation of organic matter and where artificial 

 drainage has been established, this soil is recognized as adapted to 

 the production of cabbage and of sugar beets. The total area de- 

 voted to these crops is small, and they are grown to meet unusual 

 facilities for marketing at beet factories or in the larger cities. 



The type is found in an extensive region within which there are 

 considerable variations in the mean annual precipitation from east 

 to west and in temperature from north to south. In all of the more 

 eastern and southern areas the rainfall is sufficient for maturing the 

 general farm crops suited to the warmer temperate latitudes. In 

 the extreme western areas of its occurrence there is occasionally a 



