[The characteristics of soil water and gas transport under different land use patterns in the water-wind erosion crisscross region].

Understanding the effects of land use patterns on soil water and gas transport in the water-wind erosion crisscross region can provide guidance for high-efficiency use of limited soil and water resource in the ecological rehabilitation process on the Loess Plateau. To investigate the cha-racteristics of soil water and gas transport under different land use patterns and to study the relationships between soil saturated hydraulic conductivity (K), air permeability (K) and relative gas diffusivity (D/D), we collected soil samples (0-5 cm depth) from Caragana korshinskii land, abandoned land, alfalfa land, cropland, and bare land. K was measured by constant-head method. D/D was measured by gas chamber method. K under field capacity (FC) was measured using the soil gas permeability meter. Results showed that soil bulk density (ρ) ranked as alfalfa land>bare land>abandoned land>C. korshinskii land >cropland, with that of abandoned land, bare land and alfalfa land being significantly different from that of cropland. Total soil porosity (Φ) ranked as cropland>C. korshinskii land>abandoned land>bare land>alfalfa land. Compared with cropland, Φ of alfalfa land, bare land and abandoned land was lower by 7.5%, 4.7% and 3.1%, respectively. Air filled porosity (ε) ranked as cropland>abandoned land>C. korshinskii land>bare land>alfalfa land. ε of alfalfa land, bare land, C. korshinskii land and abandoned land was lower by 38.3%, 33.6%, 12.8% and 10.1%, respectively, as compared with cropland. Soil K ranked as abandoned land>C. korshinskii land>alfalfa land>bare land>cropland, with that of the abandoned land being significantly higher than the other four land use patterns. Soil K ranked as abandoned land>alfalfa land>C. korshinskii land>bare land>cropland, with that of abandoned land being significantly diffe-rent with cropland. Soil D/D ranked as abandoned land> C. korshinskii land> alfalfa land>cropland>bare land, in which D/D of C. korshinskii land and abandoned land was significantly higher than cropland by 36.8% and 61.6%, respectively. There were significant correlations between K and K, D/D under FC conditions. Land use patterns significantly changed soil permeability. Farmland, abandonment, C. korshinskii, and alfalfa plantation improved hydraulic and gas transport parameters of the surface soil. In contrast, farmland and bare land had poor capability of soil water and gas transport.