Vol. 7, Issue 9, Part L (2025)

An incubation study was conducted during 2024-2025 with three sources of organic manures viz., FYM, vermicompost and pressmud compost and three levels of organic manures i.e., 2, 4 and 6 t ha^-1 along with a separate control treatment. The soil samples were analysed periodically at 15 day intervals up to 90 days of incubation (DAI) for release of nitrate nitrogen. Vermicompost as a source of organic manures and the manure levels @ 6 t ha^-1 recorded significantly highest NO₃^--N over all the incubation period except at 0 days of incubation. At 90 days of incubation, vermicompost application shows the highest NO₃^--N of 108.88 mg kg^-1 over other sources, while the manure application @ 6 t ha^-1 113.04 mg kg^-1. The sources and levels of organic manure interaction was non-significant at all incubation stages, still they were superior over control treatment. Incubation the soil with FYM recorded significantly higher bacterial population, urease and dehydrogenase enzyme activities at 90 days of incubation (17.30 x10⁶ cfu g^-1 soil, 11.81 µmol NH₄⁺ g^-1 soil h^-1 and 20.50 µg TPF g^-1 soil 24 hr^-1, respectively).