EFFECT OF RICE VARIETY ON METHANE EMISSION FROM LOUISIANA RICE

A field experiment was conducted to determine the effect local cultiva rs of Oryza sativa L. (rice) had on methane evolution from flooded plo ts. Semidwarf and tall varieties were drill-seeded into a Crowley silt loam (Typic Albaqualf) and methane fluxes were measured twice a week over the first and ratoon cropping seasons. Semidwarf varieties evolve d significantly less methane over both growing seasons. Over the main cropping season, semidwarfs emitted an average 185 kg CH4 ha-1 to the atmosphere compared with 300 kg CH4 ha-1 for the tall varieties. Durin g the ratoon sampling season, semidwarf and tall varieties evolved 540 and 830 kg CH4 ha-1, respectively. Compared with tall cultivars, semi dwarfs evolved 36% less methane over both seasons.