The impact of soil salinity on resource inputs in rice cultivation in Syrdarya region

Abstract

This study assesses how soil salinity affects the resource cost structure of rice (Oryza sativa L.) production (water, mineral fertilizers, labor) in irrigated agroecosystems of the Syrdarya region using a normative-analytical approach. Across salinityss classes (low: <0.3%; medium: 0.3-0.6%; high: >0.6%; very high: >1.0%), the functional relationships among water use (10,500-18,200 m³/ha), NPK application (420-720 kg/ha), labor input (68-96 h/ha), and yield (52.4-28.7 q/ha) were analyzed using multivariate regression and optimization models. The results indicate that when salinity exceeds 0.6%, water use increases by 60.0% (ΔW = +6,300 m³/ha), fertilizer use by 52.4% (ΔF = +220 kg/ha), and labor by 29.4% (ΔL = +20 h/ha), while yield decreases by 38.7% (ΔH = -20.3 q/ha). An integrated optimization model developed in accordance with O'zDST 3275:2018, O'zDST 1186:2020, and the FAO-56 and UNESCO-IHP recommendations enables a 24.8% reduction in resource intensity and increases yield up to 48.6 q/ha.