Optimizing Soil Nutrients in Pearl Millet through Combined Use of Inorganic Fertilizers and Bio-amendments

Abstract

A two-year field experiment was conducted during the Kharif seasons of 2023 and 2024 to assess the impact of inorganic fertilizers combined with Jeevamrutha and Beejamrutha on soil physico-chemical properties and nutrient availability. The study, laid out in a Randomized Block Design comprised 11 treatments and three replications, soil bulk density, particle density, porosity, water holding capacity, pH, electrical conductivity, organic carbon, and available nitrogen, phosphorus, and potassium were evaluated at 0-15 and 15-30 cm soil depths after harvest. Results indicated that T₁₁ (100% RDF + Beejamrutha + Jeevamrutha) consistently exhibited the highest available nitrogen (296.71 and 298.69 kg ha-1) and potassium (288.10 and 258.35 kg ha-1), while T₂ (100% RDF) and T₉ (100% RDF + Beejamrutha) were superior for surface and sub-surface phosphorus, respectively. T₈ (50% RDF + Beejamrutha + Jeevamrutha) enhanced soil organic carbon (0.71% and 0.62%), porosity (48.60% and 48.74%), and maintained low bulk density (1.27 and 1.28 Mg            m-³), contributing to improved soil structure and aeration, whereas water holding capacity was highest in T₁₀ at the surface and T₈ at the sub-surface. Control plots (T₁) consistently showed the lowest nutrient levels, organic carbon, and water retention, alongside higher bulk density. Overall, integrating organic amendments with inorganic fertilizers significantly improved nutrient availability and soil physical properties, with T₁₁ emerging as the most effective treatment for sustaining soil fertility and structure, demonstrating the potential of integrated nutrient management for sustainable agriculture.