Responses of soil enzymatic activity to rice residue management technologies and fertilizer levels in the rice rhizosphere on a clay loam

Crop residues returned to the soil can maintain or enhance soil quality and productivity through favourable effects on soil properties and life-support processes. The field experiment was conducted during the kharif season of 2021-2022 at the Agricultural College Farm, Bapatla, ANGRAU, Lam, Guntur, Andhra Pradesh to study the “Responses of soil enzymatic activity to rice residue management technologies and fertilizer levels in the rice rhizosphere on a clay loam”. The experiment was laid out in split-plot design with the rice residue management practices, assigned to the main plots and fertilizer levels to sub plots. The main plot comprised four different rice residue management practices viz; Straw burning (M1), Straw incorporation (M2), Straw incorporation + FYM @ 5.0 t ha-1 (M3) and Straw incorporation + DI (decomposing inoculum) + FYM @ 5 t ha-1 (M4). Three fertilizer levels were applied to rice viz., 75% RDF (S1), 100% RDF (S2) and 125% RDF (S3), as sub plot treatments. Enzyme activities viz., dehydrogenase, urease, acid and alkaline phosphatase activities at panicle initiation were significantly influenced by the crop residue management practices and fertilizer levels while their interactions were not significant. Straw incorporation + DI + FYM @ 5 t ha-1 showed significantly higher enzymatic activities among the residue management practices and among the fertilizer levels, 125% RDF is significantly superior over 75% RDF.