Vol. 13, Issue 3 (2024)

Author(s):
Lucy Taki, Biju Joseph, Gladis R, Rani B, Sajitha Rani T and Rafeekher M

Abstract:
A laboratory incubation experiment was carried out to study the nitrogen mineralization in the soil as influenced by multi-nutrient powder and pellet formulations. Multi-nutrient powder and pellet formulations were prepared using different combinations of nutrient sources like blood meal (BM), soyabean meal (SM), rock phosphate (RP), steamed bone meal (SBM), potassium sulfate (SOP), langbeinite (L), epsom salt (ES) and borax (B) and binding agents permitted by the National Programme for Organic Production. The experimental design was completely randomized design with 8 treatments and 3 replications. The multi-nutrient powder formulations include T₁ (BM + RP + SOP + ES + B), T₂ (BM + RP + L + ES + B), T₃ (BM + SBM + SOP + ES + B), T₄ (SM+ RP + L + ES + B) and pellet formulations include T₅ (BM + RP + SOP + ES + B + 4% bentonite), T₆ (BM + RP + L + ES + B + 4% starch), T₇ (BM + SBM + SOP + ES + B + 4% bentonite) and T₈ (SM+ RP + L + ES + B + 4% bentonite) which were mixed with 5kg of soil taken in pots and incubated under field capacity. Nitrogen-release potential of all treatments were determined by measuring changes in NH4+-N, NO3--N and organic N concentration in soil periodically at 60 days interval over 300 days. Results indicated that the NH4+-N content was always higher than NO3--N throughout the incubation period. T₃ released the maximum NH4+ (85.87 mg kg^-1) and NO3--N (48.53 mg kg-1) on 120th day. T8 recorded the lowest NH4+-N content and NO3--N content. The organic N content showed a declining trend throughout the incubation. The highest organic N was recorded on the 60th day for T3 (309.87 mg kg-1) and the lowest was recorded on the 300th day for T8 (201.60 mg kg-1). Nitrogen mineralization was maximum from 60 to 120 days of incubation after which it decreased gradually showing signs of stabilization at the end of the incubation period.