Effect of waste-derived synthetic zeolite on soil hydraulic properties and soil water storage parameters in sandy-loam soils

• SWRC were used to infer mechanisms driving changes in soil hydrological behaviour under zeolite treatments. • Optimization of water management in coarse soils, improving aeration and water availability for plants. • Synthetic zeolites are used as soil amendments to improve soil structure, hydraulic parameters, and SWSP properties. Zeolites are used in agriculture to amend soil chemical and physical properties. They have complex internal frameworks that enable them to alter soil texture and structure, with a direct influence on the soil’s hydrological behavior, enabling better control of groundwater contamination and more efficient irrigation management practices. This ability provides opportunities to optimize water and solute movement in coarse-textured soils while enhancing nutrient availability due to their high cation exchange capacity and water retention. In this study, a series of laboratory experiments were conducted on sandy-loam soils with different pedological characteristics, mixed with a synthetic zeolite derived from fly ash, a byproduct of coal combustion. Repacked soil samples were amended with three different zeolite concentrations (2 %, 5 %, and 10 % by weight) and subsequently analyzed for their hydraulic properties and soil water storage parameters (SWSPs) of agronomic interest. Consistent with recent research findings, our results indicate that zeolite influences soil pore-size distribution. Specifically, total soil porosity increased, with mesoporosity and microporosity rising by approximately 11% and 13%, respectively. The effects induced by zeolite showed a direct correlation with the selected soil hydraulic properties and SWSPs. Our study shows that in coarse-textured soils, incorporating an appropriate dose of zeolite enhances water retention within the soil profile while preventing excessive saturation in the root zone.