Feature and Influence of soil particle fractal dimension in the dune-meadow ecotone of the Horqin Sandy land

• 1、Inner Mongolia Agricultural University Water Conservancy and Civil Engineering College, Hohhot 010018, China

Abstract：The volume fractal dimension model was used to calculate the particle fractal dimension of 49 sampling points in the dune-meadow ecotone in the Horqin Sandy land and established the relationship between fractal dimension (D) and the different particle level for discuss the correlation between soil fractal dimension and the soil physical properties as well as soil nutrient in semiarid cold area. Resulted showed that :(1) Soil fractal dimension varied from 1.33-2.50 and it had a tendency of decrease from the meadow 、farmland in the middle of the study area to the sand dune in the north and south. The fractal dimension has the significantly difference of the different landforms and different landuse. Soil fractal dimension increased in the following order: sand dunes-semi-mobile and semi-fixed dune - fixed dune - farmland -meadow.(2) Fractal dimension was significantly positively logarithmic correlated with clay content and silt content, but significantly negatively logarithmic correlated with sand content. 100um diameter can be regarded as a critical diameter .The more the >100um content, the lower the fractal dimension; otherwise, the higher fractal dimension.(3) There existed significant correlations between fractal dimension and soil nutrient. The correlation between fractal dimension and electronically conductively 、pH、the content of SOM 、total nitrogen、total phosphorus was significantly positive，but negative with total potassium . When fractal dimension is larger than 2, the correlation between D and bulk density was negative. But , its positive with saturation moisture content

Keywords： soil fractal dimension soil physical and chemical properties；soil nutrient Horqin sandy land