Effect of rice cultivars on methane emission

A field experiment was conducted with six different cultivars of rice (Oryz a sativa L.) under similar soil and water environments to study their effec t on methane emission from intermittently flooded plots. In addition to gas analysis for methane, soil environment parameters in terms of temperature, redox potential and pH, plant biomass and the number of tillers were also measured. It was observed that the average methane flux varied significantl y with different cultivars ranging between 0.65 and 1.12 mg m(-2) h(-1). Se asonal emission was maximum for 'Pusa 933' (27.2 kg ha(-1)) and minimum far 'Pusa 169' (15.6 kg ha(-1)) with intermediate values decreasing in the ord er of 'Pusa 1019' 'Pusa Basmati' 'Pusa 834', 'Pusa 677'. The relative per c ent 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 meth ane flux. (C) 1999 Elsevier Science B.V. All rights reserved.