Soil Salt and Water Regulation in Saline Agriculture Based on Physical Measures with Model Analysis

Enhancing crop production in the saline regions of the Yellow River Delta (YRD), where shallow saline groundwater is prevalent, hinges on optimizing water and salt conditions in the root zone. This study explored the effects of various physical methods on soil water and salt dynamics during the cotton growing season in these saline areas. Three approaches were tested: plastic film mulching (FM), plastic film mulching with an added compacted soil layer (FM+CL), and ridge-furrow planting (RF). The HYDRUS-2D model (Version 3.02) was used to analyze changes in soil water and salt content in the root zone over time. The results showed that subsoil compaction significantly lowered salt build-up in the root zone, especially in the top 20 cm. Film mulching was crucial for reducing water loss in the Yellow River Delta. Crop transpiration increased by 7.0% under FM and 10.5% under FM+CL compared to RF planting. Additionally, FM+CL reduced soil salinity in the top 10 cm by 11.5% at cotton harvest time compared to FM alone. The study concludes that combining film mulching with a soil compaction layer is a promising strategy for local farmers, addressing soil water retention, salt management, and boosting cotton yields.