CLEARING OF STEEP SLOPES 285 



not been properly developed. Many rivers formerly navigable 

 have now become so filled with sediment that they cannot carry 

 boats of even moderate size. Other rivers have to be dredged 

 constantly to permit of navigation. 



Injures Crop Production. In crop production, ditches are very 

 often the cause of greater machinery cost and repairs. Moreover, 

 a crop cannot be .cared for and harvested most efficiently when 

 the field is full of ditches, nor can the land be prepared for planting 

 at as low a cost as when no ditches are present. 



CAUSES OF EROSION 



Nature's vs. Man's Way. It is the natural tendency for the 

 soil to creep down slopes or to be washed away. However, when 

 the ground is covered with leaf mold, grass, or other vegetation, 

 the creeping is comparatively slow. During rains, especially in 

 forests, the water is intercepted by the trees and drips down 

 quietly without causing any beating effect on the soil. Moreover, 

 the layer of leaf mold in the forest, grass in the open, and the organic 

 matter in the soil permit the rain to soak gradually into the ground 

 and not wash over it. In this way a steady source of water is pro- 

 vided the springs and streams. This accounts for the clear, steady 

 streams which come from virgin forests; and it also explains why 

 the pioneer farmers found so many more springs which flowed the 

 year round than may be found today. 



The development of our lands for agriculture marks the begin- 

 ning of excessive erosion in this country. It was quite necessary, 

 to be sure, that the primeval forests over the greater portion of 

 the country should be cleared away to give place for corn and 

 grain, but in the doing of it, it was entirely possible to greatly 

 lessen and even prevent the excessive damage done to the soil. 

 It has been largely because of man's activities, therefore activi- 

 ties which were carried on with but little or no thought to the 

 future that this problem of soil erosion is so serious today. 



Clearing of Steep Slopes. The clearing of non-agricultural 

 lands is one of the main causes of unnecessary erosion. Thousands 

 of acres on slopes too steep for successful farming should never 

 have been cleared, but because they were cleared, thousands of 

 acres have become ruined. Such cleared lands have been cheap. 

 Settlers moved on to them, and moved off again after they hastened 

 devastation by improper methods of farming. Many lands should 

 have been only partially cleared. 



