Effect of rice cultivars on methane emission

Abstract

A field experiment was conducted with six different cultivars of rice (Oryza sativa L.) under similar soil and water environments to study their effect on methane emission from intermittently flooded plots. In addition to gas analysis for methane, soil environment parameters in terms of temperature, redox potential and p^H, plant biomass and the number of tillers were also measured. It was observed that the average methane flux varied significantly with different cultivars ranging between 0.65 and 1.12 mg m⁻² h⁻¹. Seasonal emission was maximum for 'Pusa 933' (27.2 kg ha⁻¹) and minimum for 'Pusa 169' (15.6 kg ha⁻¹) with intermediate values decreasing in the order of 'Pusa 1019' 'Pusa Basmati' 'Pusa 834', 'Pusa 677'. The relative per cent decrease in methane emission among the cultivars was found to be in the range of 1-42.6%. Soil redox potential was negatively correlated with methane flux.