Reducing Wind Erosion with Barriers

WHEN wind shear forces on the soil surface exceed the soil's resistance to those forces, soil particles detach and are transported by the wind. Barriers ob-struct the wind and reduce the wind's speed, thus, reducing wind erosion. Application of a model, developed for evaluating ef-fectiveness of a barrier for reducing the capacity of local wind to cause erosion, illustrated: (a) Wind erosion forces are reduced more than windspeed. (b) Properly oriented barriers give much more protection when pre-ponderance of wind erosion forces in prevailing wind erosion direction is high than when preponderance is low. (c) When preponderance of wind erosion forces is low, barrier orientation is almost inconsequential. (d) Because of seasonal variation of wind direction and speed, need for and amount of protection also vary seasonally. Many trees, shrubs, tall growing crops, and grasses, and slat-fences all can be used as barriers to reduce wind erosion.