Study on Soil Infiltration Capability and Its Impact Factors of Different Land Use Types in Purple Soil Region

Soil infiltration capacity is the hot spot topic of soil erosion studies and soil physical and chemical properties have great influence on it. A new infiltration method point-source infiltration method is used to precisely evaluate the infiltration capacity in different purple soil land use types. And correlation analysis on soil physical and chemical properties and soil infiltration capacity of different land use types is performed. Results show that: (i) there is a large difference among soil physical and chemical properties in different land use types, soil water content, non-capillary porosity, capillary porosity, content of > 0.25 mm aggregates and organic matter content in the top soil are greater than those in the subsoil; (ii) soil infiltration capacity shows differences among different land use types. Land use shows great effects, in general, initial infiltration rate and average infiltration rate decrease in the order: woodland slope> slope farmland> grassland, steady infiltration rate decreases in the order: slope farmland>woodland> grassland and the time reaching stable state decreases in the order: slope farmland> woodland>grassland; (iii) correlation analysis shows that there is a significantly positive correlation between initial infiltration rate and wet sieve MWD value and structural damage rate, and it has a significantly negative correlation with capillary porosity; (iv) steady infiltration rate and non-capillary porosity show the significantly positive correlation, and it has a significantly negative correlation with the soil bulk density; (v) the average infiltration rate and non-capillary porosity and structural damage rate show a positive correlation and the correlation coefficient is large and there is a negative correlation between average infiltration rate and soil bulk density and capillary porosity, and the absolute value of correlation coefficient is relatively large. The results of this research can provide the theoretical basis for soil infiltration study in purple soil area.