Abstract:
This thesis studied the influent of rice plantation method and water management on methane emission from rice field. Field experiment was conducted at Tambon Don Maklea, Ampur Uthong, Suphanburi province. The rice varity of "Chainat 1" wascultivated for 105 days using broadcast and transplant rice plantation methods. The water management studied in the experiment includes (1) no water at above ground level, constant water levels at (2) 5 cm., (3) 10 cm., and (4) 15 cm. The methane emission was collected every 7 days by static box technique and determined by gas chromatography. The rice plantation methods and water management influenced plant growth, including plant height, plant density, dry weight of plant per area as well as shootlroot ratios. It was found that the rice planted by broadcast method emitted higher methane than those with transplant method, due to higher plant density despite shorter heights. In addition, the broadcast method also showed higher root dry weight per area, total dry weight per area, plant density and shorter root lengths than those by the transplant method which lead to more oxidation reaction in the field. In broadcast method, water management showed less influent on methane emission. Methane emissions for plantation with control water levels of 0, 5, 10, and 15 cm. were 2.52, 2.78, 2.81, and 2.71 g~~4/mZ/d, respectively. On the other hand, with transplant method, the water management should not be less than 5 cm. of water level.