Effect of DCD, FYM and Moisture regime on nitrous oxide emission from an Alluvial soil in rice-wheat cropping system

Nitrous oxide (N₂O) is an important greenhouse gas accounting for 5 per cent of the greenhouse effect and responsible for the destruction of the stratospheric ozone. Emission of N₂O from an alluvial soil in rice-wheat cropping system as influenced by applications of urea, urea plus dicyandiamide (DCD) and urea plus farmyard manure (FYM) was studied in a field using closed chamber technique. Effect of water management on N₂O emission was also assessed. Total emission of N₂O-N from the rice field varied between 353 and 820 g ha⁻¹ while in wheat field it was between 322 and 857 g ha⁻¹ depending upon fertilizer application and water management. Application of FYM in rice and DCD in rice and wheat reduced emission of N₂O-N. In rice, intermittent wetting and drying condition of soil resulted in higher N₂O-N emission than that of saturated soil condition. Treatments with 5 irrigations gave higher N₂O-N emissions from wheat field than those with 3 irrigations.