Methane Emission from Indonesian High Yielding Rice Cultivars

ABSTRACT Rice is an important crop for Indonesian people. Through the Ministry of Agriculture (MoA), rice research on improving productivity and quality has been conducting. The MoA has been producing 4-5 of high yielding rice cultivars every year. But, unfortunately rice cultivation is considered as a contributor of methane emissions. Increasing methane concentration in the atmosphere could lead global warming. A study to identify the quantity of methane emissions from high yielding rice cultivars was conducted in Indonesian Agricultural Environment Research Institute (IAERI). Eight rice cultivars, consisted of one old and famous rice cultivar in farmer’s practices (Ciherang) and seven new rice cultivars (Unsoed 1, Hipa 14 SBU, Unsrat 2, Inpari 23, Inpari 28, Inpari Sidenuk and Inpari 16) were used. All of rice cultivars were planted using direct seeded system on July – November 2017. Measurement of methane fluxes was carried out using automatically closed chambers installed permanently in the field. It was observed that that the average methane fluxes varied with different cultivars ranging between 4.22 and 609.68 mg m-2 day-1. Seasonal emission rates of methane were significantly different among the cultivars. The high methane emissions were observed in the cultivar of Unsoed 1 (340 kg ha-1), followed in Hipa 14 SBU (261 kg ha-1). The intermediate methane emissions were observed in the cultivars of Inpari 23 (196 kg ha-1), Inpari 16 (189 kg ha-1) and Inpari Sidenuk (188 kg ha-1). The lower methane emissions were observed in the cultivars of Ciherang (184 kg ha-1), Unsrat 2 (164 kg ha-1) and Inpari 28 (147 kg ha-1). The rice yield was not significant among rice cultivars. The highest and lowest rice yields were 6.18 and 5.57 t ha-1 produced by the cultivars of Inpari Sidenuk and Inpari 28, respectively