Equivalent wind-erosion protection from selected crop residues

The wind erosion equation, which estimates annual potential ero-sion, requires that all vegetation (dry weight per area) be expressed as a small grain equivalent (SG)e. Wind-tunnel tests were used to determine that equivalent for five growing crops. These are corn (Zeu mays L.), cotton (Gossypium hirsutum L.), grain sorghum [Sorghum bicolor (L.) Moench], peanuts (Aruchis hypogaeu L.), and soybean [Glycine mux (L.) Merr.] in rows both perpendicular and parallel to flow. Compared with the small grain standard, all the growing crops evaluated in rows perpendicular to flow effectively prevented erosion. Because measured or estimated amounts of aboveground biomass are needed in determining (SG)es, simple power equations relating biomass to plant height were developed. For short-term application of the wind erosion equation by crop stage period or in models with daily time steps, an equation was derived for calculating (%)e fro