The Research Of Cultived Land Soil's Grannle Fractal Features

In the text, the mechanical constitution of traditional cultived farmland soil granule and protective cultived farmland soil granule was analysed, the fractal dimension of soil grain was computed,and the fractal features of soil granule was researched. At the same time, the soil's erosion experiment of traditional cultived farmland soil and protective cultived farmland soil was done in wind tunnel, after blowing in different speed wind,the fractal dimension of soil granule in surface was got, the fractal dimension of two kinds of farmland soil granule and the changing regulation which is made up of granularity in different wind speed were researched. According to the result, the fractal dimension of soil granule is correlated closely with the constitution of soil granularity degree, so we can replace the mechanical constitution of soil with the fractal dimension of soil granule, it can be used to evaluate the soil's erosion degree of farmland soil as a quantitative norm; the fractal dimension of protective cultived farmland soil granule is bigger than the fractal dimension of traditional cultived farmland soil granule, and in the surface of soil, the fractal dimension of protective cultived farmland soil granule is obviously bigger than the fractal dimension of traditional cultived farmland soil granule, it demonstrates that the condition of protective cultived farmland soil is better than the condition of traditional cultived farmland soil; sufferred blowing in the same speed wind,the changing tendency of the traditional cultived farmland's fractal dimension is faster than the changing tendency of the protective cultived farmland's fractal dimension,it proves that executing protective cultivation and leaving stubbles to cover field can reduce the effect of wind erosion for the farmland soil.