Qbiective The aims were to investigate the impact of different stand conditions on soil infiltration properties, in order to provide a theoretical basis for erosion prevention and ecological management in the region.

Methods Taking four stand types of Pinus tabuliformis, Armeniaca sibirica, Populus davidiana and Caragana korshinskii as the research subjects in the loess hilly and gully region. The soil infiltration process of four typical stands was measured by field double-ring method and indoor experiment in August, 2023. And the soil infiltration characteristics under different stands were analyzed. The further discussions were conducted on the influence of soil physicochemical properties on infiltration and the adaptability of infiltration models.

Results In terms of soil properties, the Populus davidiana stand exhibited the best condition, characterized by the lowest bulk density, the highest soil porosity ratio, and relatively high organic matter content and root biomass. Followed by Prunus armeniaca and Pinus tabulaeformis, and Caragana korshinskii had the worst soil properties. After 45 min of infiltration test in four kinds of artificial forest land, it was found that the initial infiltration rate, stable infiltration rate, average infiltration rate and cumulative infiltration rate of different artificial forest lands were significantly different. According to the evaluation of four infiltration indices and the soil infiltration performance of forest land, which were in the order of: Populus davidiana > Armeniaca sibirica > Pinus tabuliformis > Caragana korshinskii. Based on the Kostiakov, Philip, and Horton models, simulations of water infiltration processes under different stands were conducted, and the Horton model showed the highest fitting precision. After the infiltration experiments, the soil field capacity and saturated water content of various stands were observed to be: Populus davidiana > Armeniaca sibirica > Pinus tabuliformis > Caragana korshinskii. The results of correlation analysis showed that there was a significant negative correlation between 4 infiltration characteristics and soil bulk density (P < 0.01), and significant correlated with non-capillary porosity (P < 0.01), it was positively correlated with soil organic matter content and capillary porosity (P < 0.05).

Conclusion The comprehensive test results show that Populus davidiana can improve the physical and chemical properties of the soil in the loess area and significantly improve the soil permeability and water-holding capacity. This could effectively delay the occurrence of surface runoff, so that the soil to a greater extent to play the ability of anti-erosion, suitable for soil and water conservation work in the promotion.