Abstract
In Kazakhstan, food safety is a pressing issue due to water and soil pollution. This study examined the effect of natural zeolite as an alternative hydroponic substrate on the physicochemical properties of the medium and the physiological and metabolic responses of two agricultural crops: Medicago sativa L. and Lactuca sativa L. BET analysis revealed that the zeolite possesses a substancial specific surface area (22 m²/g), ensuring effective moisture retention and gradual nutrient release. After plant cultivation, these parameters decreased moderately, confirming the filling of the pores with organic compounds without loss of key properties. In experiments with Medicago sativa, zeolite provided better aeration and stable moisture, promoting the development of a branched root system and increased seedling viability compared to an artificial substrate. Metabolic analysis of three Lactuca sativa varieties revealed cultivar-specific adaptive responses. Zeolite increased the synthesis of fatty acids and their derivatives, reflecting membrane-protective restructuring, while sugar and terpenoid content varied depending on the variety. The results confirm the suitability of zeolite as a stable substrate for hydroponic production, allowing for optimized water consumption, improved root development, and enhanced physiological stability of plants.