A phytotoxic, cytogenotoxic and respirometric evaluation of a fertilizer composed of multicomponent oxide glasses, designed for sustainable agriculture

Abstract

The excessive use of conventional fertilizers has caused serious environmental problems, including soil salinization and acidification, global warming, eutrophication, and harm to biota, resulting from accumulation of nutrients in the soil. Glass fertilizers emerge as a potential solution by ensuring gradual nutrient release and offering high compositional versatility. However, little is known about their ecotoxicological potential and environmental safety. Therefore, the present study sought to evaluate the ecotoxicological effects of a multicomponent, slow-release glass oxide fertilizer on the test organisms Lactuca sativa and Allium cepa, to analyze their phytotoxic and cytogenotoxic potential, respectively. The fertilizer was evaluated at five concentrations (0.317, 0.633, 1.267, 2.534, and 5.063 g/L), obtained by dissolving the material in water under continuous stirring for 24 to 144 h. Its effects on soil respiration were assessed through a respirometry test, in which the fertilizer was directly applied to the soil at the same concentrations (g/kg). The fertilizer enhanced soil microbial respiration without inducing toxicity. In L. sativa, the germination index showed that only the lowest concentration was non-phytotoxic across all solubilization times. For cytogenotoxicity, the fertilizer did not affect the mitotic index of A. cepa and was genotoxic only at the highest concentration and longest release time. Thus, such results demonstrate a high potential for applicability of the tested glass fertilizer, especially from an environmental perspective, as long as an ideal concentration of use specific to each crop is established.