Jiongchang Zhao

and 3 more

Soil water is a crucial factor for the growth of vegetation and sustainable development in water-limited areas. After large-scale vegetation restoration on the Chinese Loess Plateau, understanding the relationship between vegetation and deep soil moisture has become a crucial focus in current research. In this study, we selected artificial forest ( Pinus tabulaeformis, Robinia pseudoacacia, and Platycladus orientalis), apple orchard, secondary forest and farmland as the research objects, and native grassland as the control, using soil drilling techniques, we systematically monitored the soil water content of 0-10 m soil layer over two hydrological years, and explore the effects of different vegetation types on soil water deficiency. The results showed that: (1) The deep soil water various significantly among different vegetation types, which indicating the depth of the influence of vegetation on soil water has reached 10 m. (2) The mean deficit size values of P. tabulaeformis (0.14), R. pseudoacacia (0.17), P. orientalis (0.07), apple orchard (0.15) and secondary forest (0.10) and farmland (0.27) were positive in 0–1 m, indicating that surface soil water had accumulated during more than half of the sampling periods. In the 2–10 m soil layer, the mean deficit size was negative in all vegetation types except in farmland, leading to soil desiccation. The deficit size was found to fluctuate with soil depth. (3) Soil water deficit degree was affected by a combination of soil properties and vegetation growth. Altitude, soil bulk density and canopy density had a significant impact on soil water deficit. Our results indicate that the current afforestation model could lead to the deficiency of deep soil water. Therefore, in planning future vegetation allocation and management, it is imperative to make reasonable vegetation structure according to the available local soil and water resources.