Integrating Biofertilizers in Nutrient Management of Millets: A Review of Advances and Prospects

Abstract

Millets, often called “nutri-cereals,” are gaining renewed attention for their resilience, nutritional value, and adaptability to marginal environments. However, their productivity is still restricted by poor soil fertility and inefficient nutrient management. Integrating biofertilizers into millet cultivation offers an eco-friendly, cost-effective, and sustainable alternative to conventional fertilizer practices. This review synthesizes recent advances in biofertilizer application, nutrient dynamics, and their combined effects on millet growth, yield, and grain quality. Biofertilizers such as Rhizobium, Azospirillum, Azotobacter, and phosphate-solubilizing bacteria (PSB) enhance nutrient availability by fixing atmospheric nitrogen, solubilizing phosphorus, and mobilizing micronutrients, while mycorrhizal associations improve root absorption and stress tolerance. Evidence suggests that inoculation with appropriate microbial strains can increase millet yield by 20–30%, improve nutrient uptake efficiency, and maintain soil health. The review further highlights the influence of processing on millet's antioxidant potential, where techniques such as germination and malting significantly enhanceing the bioavailability of phenolic compounds and antioxidant capacity. Policy recommendations to promote millet production include strengthening seed inoculation protocols, optimizing organic–inorganic fertilizer combinations, and integrating biofertilizers within national nutrient management frameworks. The convergence of biofertilizer technology with sustainable agronomic practices holds immense potential to revitalize millet cultivation, improving nutritional security, and reducing chemical fertilizer dependency in smallholder farming systems.