Variation in soil infiltration properties under different land use/cover in the black soil region of Northeast China

Soil infiltration properties (SIPs) of infiltration rate and saturated hydraulic conductivity significantly affect hydrological and erosion processes, thus, knowledge of SIPs under different land use/cover are vital for land use management to control soil erosion for realizing the sustainable development of the small agricultural watershed. Nevertheless, few studies have been carried out to investigate the differences in SIPs and their dominant influencing factors between different land use/cover in the black soil region of Northeast China. Therefore, eight typical land use/cover were selected to clarify the variations in SIPs between different land use/cover and further identify their dominant influencing factors. SIPs of initial infiltration rate (IIR), steady infiltration rate (SIR), and saturated hydraulic conductivity (Ks) were determined under eight typical land use/cover (forestland, shrub land, grassland, longitudinal shelterbelt, transverse shelterbelt, agricultural road, and cropland of Zea mays L. and Glycine max (Linn.) Merr) using a tension disc infiltrometer with three pressure heads of −3, −1.5, and 0 cm. The results of one-way ANOVA analysis showed that SIPs varied greatly between different land use/cover. Shelterbelt plant with Populus L. had the maximum IIR, SIR, and Ks, and then followed by shrub land, agricultural road, cropland, grassland, and forestland. Spearman correlation analysis indicated that SIPs were significantly correlated with soil and vegetation properties. Redundancy analysis revealed that differences in SIPs between different land use/cover were dominantly attributed to the differences in soil texture, field capacity, and plant root mass density, which explained 79.36% of the total variation in SIPs. Among these dominant influencing factors, the results of structural equation model indicated that the indirect effects of plant root and soil texture played the most important role in variations of SIPs via affecting soil texture and pore characteristics. These results have significant implications for the precise prediction of watershed hydrological and erosion processes, also provide a scientific basis for guiding the distribution pattern of land use in the cultivated watershed.