Wind Erosion: Processes and Predict ion

Conditions conducive to wind erosion exist when the soil is loose, dry, and finely granulated; the soil surface is smooth and vegetative cover is sparse or absent; the susceptible area is sufficiently large; and the wind is strong and turbulent enough to move soil. Those conditions often prevail in semiarid and arid climates, for example west of the 99th meridian in the USA. The many problems researchers face in determining effects of erosion on crop productivity are represented by Fig. 10-1. A host of interactions determines crop production or yield. One way to isolate the effects of erosion in this complex crop-production system is to translate the problem from practical terms to basic concepts at the process level, where research is performed. Even though wind erosion damages soil, crops, and the environment, we will omit any discussion of environmental damages, other than to cote that future experimental research and modeling should include such impacts on crop yields. In this paper, wind erosion will be linked to productivity through its alteration of surface-soil properties and/or soil depth. This alteration must then be linked to other factors that influence the growth and development of crops. 10-1 WIND EROSION AND CROP PRODUCTION Wind erosion is a set of processes that contribute to the motion of soil from its initiation until final deposition. Neglecting the abrasive effect of aggregate impact on crops, the interface between wind erosion and the crop