Zeolites for Sustainable Agriculture: From Soil Amendment and Nutrient Retention to Environmental Remediation and Next-Generation Delivery Systems

Abstract

Agricultural intensification has increased pressure on soil, water and nutrient resources while accelerating nutrient losses, salinity, contaminant mobility and other environmental impacts. Zeolites—crystalline, hydrated aluminosilicates characterised by interconnected channels, cages, high cation-exchange capacity and reversible water sorption—offer a multifunctional mineral platform for addressing several of these challenges simultaneously. This review synthesises the supplied literature on natural and synthetic zeolites and reframes it around the central question of how zeolite structure and surface chemistry can be translated into measurable gains in agricultural resource-use efficiency and environmental protection. The evidence indicates that zeolites can modify soil physical properties, increase water retention, buffer soil acidity, retain ammonium and other cationic nutrients, reduce nutrient losses, and support slow-release fertiliser systems. Their adsorption and ion-exchange properties also underpin applications in heavy-metal immobilisation, pesticide removal, wastewater treatment and controlled delivery of agrochemicals. Natural clinoptilolite is particularly attractive because of its abundance, comparatively low cost and strong ion-exchange behaviour, whereas synthetic and modified zeolites provide opportunities for tailoring pore structure, surface charge and selectivity. However, responses are highly context dependent: soil texture, mineralogy, zeolite composition, particle size, application rate, pH, contaminant speciation and amendment combinations can alter outcomes. Recent research increasingly emphasises zeolite–biochar, zeolite–compost, organo-zeolite and nanozeolite systems, but field-scale validation, long-term environmental safety, economic assessment, standardised characterisation and life-cycle analysis remain insufficient.