Effects of Straw Management Practices and Nitrogen Application on Paddy Straw Decomposition: An in situ Nylon Bag Study

Abstract

An in-situ field experiment was conducted during the rabi season of 2020–21 at the Regional Agricultural Research Station, Polasa, Jagtial, to evaluate the effects of paddy straw management and nitrogen application on straw decomposition. The experiment followed a factorial randomised block design with three replications, comprising two straw-management options—incorporation without phosphorus and incorporation with phosphorus—and four nitrogen levels: 100%, 110%, 115%, and 120% of the recommended dose of nitrogen. Nylon mesh bags containing 32 g of paddy straw were buried at transplanting, and decomposition was assessed at 15-day intervals and after harvest. Straw decomposition increased progressively over time under both phosphorus treatments. Incorporation with phosphorus consistently produced greater decomposition than incorporation without phosphorus, reaching 42.41% at harvest compared with 37.53% without phosphorus. Nitrogen level significantly influenced decomposition at 15 and 30 days after transplanting, whereas differences among nitrogen levels were non-significant at later stages. The interaction between straw-management practice and nitrogen level was non-significant throughout the assessment period. The findings indicate that phosphorus application with incorporated paddy straw enhanced decomposition under the experimental conditions, while the effect of increased nitrogen application was primarily evident during the early decomposition period. The nylon mesh bag method permitted temporal assessment of biomass loss under field conditions.