SOIL EEOSIOJSr IN" THE SOUTH. l3 



N. C. It differs from the others in that the terrace Ihies are not 

 level, but contour the field at a grade of 1^ inches to 14 feet. This 

 terrace is a broad bank of earth mth gently sloping sides. It is con- 

 structed along the hues laid off' by back furrowdng and puUing the 

 soil to this line, thus forming a low dike. This terrace has been 

 described in detail in a Government pubhcation.^ It gives a gradu- 

 ally sloping side both above and below its highest point, so that culti- 

 vation may be carried on across the ridge in any direction. While 

 providing protection to the land it also eliminates the waste land and 

 breeding places for insects afforded by the weeds or grass growing on 

 the terrace ridges. For most agricultural lands it is the ideal ter- 

 race, but it may not be suitable for some soils of a hght character. 



OTHER METHODS OF PREVENTION. 



In addition to the use of terraces to prevent washing of the soU 

 it is generally advisable to plow deeply. By plowing deeply the soil 

 is so loosened that the rate of absorption becomes much greater and 

 the land is enabled to take care of a heavier sudden rainfall. The 

 same thing is accomplished by incorporating organic matter in the 

 son or by use of tile drains. In fact, any method that will assist 

 in the efficient drainage of a soil will also do much toward the pre- 

 vention of excessive erosion. The interstitial spaces become larger 

 in a well-dramed soil, so that the movement of water through the soil 

 is more rapid. Hence a heavy precipitation may be absorbed as 

 rapidly as it falls. 



Prevention of erosion is accomplished by having some vegetation 

 cover the entire surface of the soil. This offers resistance to the 

 water flowmg over the surface and retains it long enough for the 

 soil to absorb larger quantities than would be possible under clean 

 culture. The expedient of alternatmg strips of cultivated soil with 

 grass strips is sometimes resorted to, and on moderately rolling land 

 this is fairly effective. Again, land that would be unsuitable to clean 

 culture may be utilized for orchards with a cover crop on the soil. 



The use of winter crops should find application especially m the 

 Southern States. The winter precipitation, which constitutes a 

 large part of the total, is largely in the form of rain, and in many cases 

 it falls on land barren of any crop. The use of rye or some winter 

 crop would be of great advantage in holding the soil and preventing 

 the destructive erosion resulting from the winter rains. 



The method of using liillsidcs for orcliards and maintaining a grass 

 cover crop has givtsn rise to (considerable discussion as to the relative 

 value of the orchard with such a crop or with clean culture. As a 

 means of preventing wash, the grass is efTectivc, but the general 



» Clr. No. 04, Qureau of Plant Industry, U. 8, Dept. Agr. 



