| Abstrakt: |
Tests were conducted in the field to determine the interrelationships of surface drag, surface roughness, plant residue cover, percent of soil material less than 0.42 mm in diameter, and soil loss obtained by means of a portable wind tunnel. The tests were conducted at Garden City, Colby, and Manhattan, Kans. on plots prepared especially to obtain a range in residue cover over a range in soil structure. The data obtained were analyzed according to standard multiple regression and correlation procedure and presented in terms of regression equations. The exponential regression equations provided a satisfactory expression of the functional relationships. Factors effecting variation in results between the different locations were cited. The regression equations illustrate the effect of each factor on soil loss. On the basis of relationships secured at three locations, an exponential equation approximating the results of the tests as a whole was developed. In this equation, soil loss, X, in pounds per acre is shown to vary directly as the 2.5 power of the surface drag of the wind and the 3.5 power of the percent of soil fractions less than 0.42 mm in diameter. It varied inversely as the 0.8 power of the weight of surface residue. A simplified clod structure‐residue index of soil loss, wherein the surface drag of the wind is held constant at 3,000 pounds per acre, is presented. |
