Sustainable Water Management of Drip‐Irrigated Green Beans: Evaluation of Yield, Irrigation Water Productivity, Soil Moisture and Salinity Dynamics in the Soil by the SALTMED Model Under Organic Soil Mulching and Water Stress

ABSTRACT This study examined how organic mulching and deficit irrigation affect soil moisture and salinity in sandy soils, comparing field data with the SALTMED model outputs. The field experiment featured four irrigation treatments—100% IRg, 75% IRg, 50% IRg and 50% IRg with partial root drying (PRD)—and four mulching treatments: uncovered soil (UC), plastic mulch (PM), rice straw mulch (RSM) and compacted rice straw mulch (CRSM) over the 2022 and 2023 seasons. In 2022, the 50% IRg–PRD with CRSM yielded the highest at 8611 kg ha −1 , while the 50% IRg with UC had the lowest at 6009 kg ha −1 . The highest irrigation water productivity (IWP) was 5.56 kg m −3 under the 50% IRg–PRD and CRSM treatment, and the lowest was 2.45 kg m −3 with 100% IRg and UC. The SALTMED model accurately simulated crop yields with R 2 values of 0.982 and 0.949 across all treatments and high R 2 values of 0.996 and 0.992 for observed versus simulated IWPs. The model showed significant sensitivity in simulating soil moisture and salinity changes across treatments.