Optimizing Spinacia oleracea L. yield in semi-arid region: The role of hydrogel in water scarcity mitigation

The study investigated how the combination of hydrogel (HG) and Phosphate-Solubilizing Bacteria (PSB) would improve soil health and enhance spinach (Spinacia oleracea L) yield under water-stress conditions. The study investigates the synergistic effects of PSB with hydrogel (PSB+HG) integration on enhancing soil water retention, nutrient availability, microbial biomass and crop productivity in semi-arid agroecosystems. Five amendments were checked: No addition of manures (control), Di-ammonium phosphate (DAP), DAP with hydrogel (DAP+HG), PSB and PSB with hydrogel (PSB+HG). Several physicochemical and biological analyses were conducted before and after harvest. The combination of PSB+HG has shown superior results compared to the other treatments; it has enhanced the Nitrogen with 242±14.52 kg/ha, water holding capacity with 79 % and microbial biomass carbon with 98±6.64 µg/g. Pearson correlation analysis further revealed a significant positive relationship between soil fertility parameters, specifically between nitrogen and water-holding capacity (r = 0.8021), nitrogen and microbial biomass carbon (r = 0.8028) and water-holding capacity and organic carbon (r = 0.8029). These correlations emphasize the synergistic effects of improved water retention and microbial activity on soil nutrient availability. The enhancement after harvest created a condition suitable for the improvement in the fertility of the soil, increasing the environment suitable for plant growth, leading to a better yield of the Spinach of 27.9±2.01g/m2. Our findings highlighted that effective incorporation of biological agents such as PSB with water-retaining material, such as hydrogel, improves the soil and plant growth, particularly in semi-arid regions where water is a main deficiency that hinders crop production.