Experimental study of mulching effects on water restoration of deep, desiccated soil in a loess hilly region.

Drought climate and human activity have led to serious soil desiccation in the loess hilly region. Mulching measures can effectively increase rainfall infiltration and reduce evaporation, thus improving soil moisture status. The objective of this study was to explore the characteristics of water restoration of deep desiccated soil under different mulching measures and determine a promising mulching measure. We built large-scale simulation desiccated soil columns in the field (soil columns with an 0.8-m diameter and 10-m depth). Six kinds of treatments were tested: film mulching, gravel mulching, branch mulching, planting of jujube tree (Ziziphus jujuba Mill.) and robinia (Robinia pseudoacacia L.), and bare land as the control. The results showed that different mulching measures can increase soil water storage and alleviate the soil drying phenomenon to different degrees. Compared with other treatments, film mulching is more effective, with larger increment of soil water storage, deeper restoration of soil dry layer, and simple to operate in loess hilly region. So, we recommend film mulching, which is a feasible method to improve the soil desiccation status in hilly loess areas.