Silicon Nano-Fertilizer-Enhanced Soybean Resilience and Yield Under Drought Stress.

Abstract

Drought stress threatens agriculture and food security, significantly impacting soybean yield and physiology. Despite the documented role of nanosilica (n-SiO₂) in enhancing crop resilience, its full growth-cycle effects on soybeans under drought stress remain elusive. This study aimed to evaluate the efficacy of n-SiO₂ at a concentration of 100 mg kg^-1 in a soil medium for enhancing drought tolerance in soybeans through a full life-cycle assessment in a greenhouse setup. To elucidate the mechanisms of n-SiO₂ action, key physiological, biochemical, and yield parameters were systematically measured. The results demonstrated that n-SiO₂ significantly increased silicon content in shoots and roots, restored osmotic balance by reducing the Na⁺/K⁺ ratio by 40%, and alleviated proline accumulation by 35% compared to the control, thereby mitigating osmotic stress. Enzyme activities related to nitrogen metabolism, including nitrate reductase (NR) and glutamine synthetase (GS), improved by 25-30% under n-SiO₂ treatment compared to the control. Additionally, antioxidant activity, including superoxide dismutase (SOD) levels, increased by 15%, while oxidative stress markers such as hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) decreased by 20-25% compared to the control. Furthermore, yield components were significantly enhanced, with pod number and grain weight increasing by 15% and 20%, respectively, under n-SiO₂ treatment compared to untreated plants in drought conditions. These findings suggest that n-SiO₂ effectively enhances drought resilience in soybeans by reinforcing physiological and metabolic processes critical for growth and yield. This study underscores the potential of n-SiO₂ as a sustainable amendment to support soybean productivity in drought-prone environments, contributing to more resilient agricultural systems amidst increasing climate variability. Future research should focus on conducting large-scale field trials to evaluate the effectiveness and cost-efficiency of n-SiO₂ applications under diverse environmental conditions to assess its practical viability in sustainable agriculture.