Physiological and Soil Health Approaches for Sodic Rice Soil Rehabilitation through Biostimulants and Micronutrients

Sodic soils severely constrain rice (Oryza sativa L.) productivity by impairing soil structure, nutrient availability and key physiological processes such as photosynthesis, ion homeostasis and antioxidant metabolism. High soil pH and excess sodium disrupt Na+/K+ balance, reduce chlorophyll synthesis and induce oxidative stress, ultimately limiting rice growth and yield. This review focuses on the physiological aspects of sodic stress and highlights the integrated role of biostimulants and micronutrients in improving rice performance under sodic conditions. Biostimulants including humic substances, seaweed extracts, protein hydrolysates, plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi enhance root growth, nutrient uptake, antioxidant defense and stress tolerance. Micronutrients such as zinc, iron and manganese support chlorophyll biosynthesis, enzymatic activity and reactive oxygen species detoxification. Their combined application improves photosynthetic efficiency, nutrient use efficiency, soil biological activity and grain yield, offering a sustainable strategy for rehabilitating degraded sodic rice soils.