Trade‐Offs Between Maize Productivity Improvement and Topsoil Salinization Risk Under Shallow Burial Drip Irrigation in Semi‐Arid Regions

Drip irrigation is widely used to conserve water and maintain crop production in water‐limited regions. However, how contrasting drip irrigation systems shape soil water‐salt movement, water and nitrogen (N) use, and maize productivity in semi‐arid environments remains poorly understood. Here, we conducted a two‐year field experiment (2019–2020) with a randomized complete block design to compare shallow buried drip irrigation (SBDI) and mulched drip irrigation (MDI). Relative to MDI, SBDI increased grain yield, dry matter accumulation, and N uptake by 5.86%, 3.11%, and 9.58%, respectively, contributin to greater water and N use efficiency. Soil salinity dynamics were closely coupled with soil water movement, representing a remarkable accumulation in the 0–20 cm soil layer under SBDI compared to MDI, owing to higher evapotranspiration. Although both irrigation systems resulted in soil salt accumulation, SBDI was more conducive for chloride ion elution. Partial least squares path modeling, Random forest, and Mantel tests suggested that water N utilization and salt dynamics were highly related to maize productivity. Our findings enrich the theoretical framework for preventing secondary soil salinization by inhibiting soil resalinization via water regulation or interlayer installation. In the future, the integration of SBDI with desalination measures may be a crucial strategy for enabling sustainable high‐yield maize production in semi‐arid regions.