Mitigating cadmium-stressed spinach by the synergistic effect of vermicompost and selenium: associated heath risks...

Using organic and inorganic amendments as supplements can significantly mitigate abiotic stress conditions. Here, we combined vermicompost and selenium (Se) to assess their impact on the morpho-physio-biochemical traits of spinach under cadmium (Cd) stress. The experiment included two factors: Cd stress (no Cd and Cd applied at 20 mg kg^-1 of soil using CdCl₂) and four treatment combinations, no amendment (control), selenium applied at 1 mg L^-1 using sodium selenate, vermicompost added at a 10% (w/w), and a combined treatment of selenium and vermicompost. Results showed that Cd stress significantly reduced plant growth and physiological parameters compared with the control. In contrast, Cd stress led to increases in proline accumulation and electrolyte leakage, indicating stress responses. Treatments involving vermicompost and selenium, both individually and in combination, improved dry biomass, enhanced soluble sugar content, and modulated enzymatic antioxidant activity. These physiological and biochemical improvements contributed to enhanced tolerance to Cd stress, as indicated by reduced electrolyte leakage. The combined application of vermicompost and selenium proved more effective than individual treatments, resulting in lower Cd accumulation in leaves and consequent reduction in potential health risks. Overall, the synergistic effect of vermicompost and selenium demonstrates significant potential as a sustainable strategy for ameliorating Cd stress in spinach. Future research should explore the long-term efficacy of this combination approach under diverse field conditions to validate its practical applications for mitigating heavy metal toxicity.