Abstract

                                The field experiments were carried out to assess the influence of Dicyandiamide (DCD) along with nine different nitrogen management practices on emission of methane (CH4) and nitrous oxide (N2O) under intensive paddy system of Cauvery Delta Zone. The CH4 and N2O efflux clearly showed daily and seasonal fluctuations. Among the treatments, Leaf Colour Chart (LCC) based N (30 kg N ha-1 keeping the LCC value 4 as standard + DCD @ 10 % of applied N) recorded the lowest average emission of 0.50 mg.m2.day-1 and 2.93 mg.m2.day-1 of N2O and CH4, respectively. Irrespective of all treatments, among the critical stages of crop growth, flowering stage recorded highest emission of 23 % N2O and 50 % of CH4 when compared to tillering stage. Among the “N” applied treatments, Leaf Colour Chart (LCC) based N + DCD recorded the lowest seasonal green house gas emission (0.49 kg ha-1 & 0.44 kg ha-1 of N2O and 2.94 kg ha-1 & 3.20 kg ha-1 of CH4 during Kharif and Rabi seasons, respectively) along with higher paddy yield (12 to 15%).

Key words : Dicyandiamide, Nitrogen fertilizer, Nitrous oxide, Methane, Paddy