28^ Illinois State Dairymen's Association. 



Prevention of Sheet Washing. 



It would commonly be taken for granted that the thing of 

 first importance in this discussion is the matter of preventing the 

 formation of gullies in cultivated fields, but this is not the case. 

 The beginning of the trouble is usually due to sheet washing, and 

 as a rule gullying occurs in the latter stages of the general pro- 

 cess of land ruin. If we can prevent sheet washing we will 

 lessen very largely the possibilities of gullying in cultivated fields. 



Four general methods are employed for the prevention of 

 sheet washing : First, the growing of cover crops to decrease the 

 movement of water and soil ; second, increasing the organic mat- 

 ter content to bind the soil particles together; third, using 

 methods of tillage to check the velocity of the run-off and to 

 cause greater absorption; and fourth, by terraces and hillside 

 ditches, thus modifying the steepness of the slope, and conducting 

 the surplus water off at such slope as will produce little or no 

 washing. 



1. Cover Crops. — In the management of rolling land a 

 rotation should be adopted that permits the land to be in pasture 

 and meadow for a large part of the time, or that at least keeps a 

 covering of vegetation on the soil so much of the time as possible. 

 Before these rolling and hilly lands were brought under cultiva- 

 tion they were largely covered with vegetation of some form. 

 The leaves of trees and fallen branches, together with the smaller 

 perennial, biennial, and annual plants, formed a covering that 

 very effectually prevented the soil from washing. The rainfall 

 was held by the layer of leaves and mold and the run-off was 

 given off slowly to the streams. As soon as the protecting forest 

 was removed the run-off was materially increased, the water run- 

 ning ofT in a flood almost as fast as it fell. The upland timber 

 soils of the state were usually in poor physical condition to begin 

 with, or became so after a few years of cropping, and this condi- 

 tion allows only comparatively slow percolation. The soils should 

 be kept covered with vegetation as much as possible. If a culti- 

 vated crop is grown such as corn, a cover crop should be grown 

 in the corn to protect the soil from washing during fall, winter, 

 and spring. This crop can be put in just before or after the last 

 cultivation. Rye is one of the best, because it lives through the 

 winter and makes a fair growth of top and an abundance of fine 

 fibrous roots that hold the soil particles in place. It may be left 



