Seasonal soil water dynamics under different tree plants and mulching treatments in the Loess Hilly Region of China

There is large-scale deep soil desiccation in the Loess Plateau due to excessive vegetation rehabilitation over the years. It is the key to soil desiccation in the Loess Plateau in response to the lingering concern about the role of plant reintroduced and water restoration in areas with deep soil desiccation. However, not much studies have been done to address this deepening concern. To that end, large field soil columns were used to simulate dry soil and measure dynamic soil water changes in the 0–10 m soil layer under different mulching treatments. The results showed that under severe desiccation of deep soil layer, reintroduced plants relied on local rainfall for normal growth. Here, a new soil water balance emerged in the dry soil layer due to the different water uses of the reintroduced plants. Generally, deep-rooted perennial plants induced severe soil desiccation. Surface mulching treatments strongly influenced soil water restoration, with restoration rates of 23.5 cm/season for stone mulching, 23.5 cm/season for tree branch mulching, 38.8 cm/season for cloth mulching and 30.6 cm/season for white plastic film mulching. The findings of the study are critical for sustainable ecological construction especially as it relates to soil water restoration in Hilly Loess China.