Rong, Xiang creator Weihan, Su Chairperson Chongrak Polprasert Examination Committee Samorn Muttamara Examination Committee Asian Development Bank Scholarship Donor text series technical report th Bangkok Asian Institute of Technology 1994 continuing eng 59 leaves Methane (CH4) and nitrous oxide (N20) are two important greenhouse gases. Nitrous oxide is also responsible for depletion of the stratospheric ozone layer. Rice fields are a major source of anthropogenic methane emission and possibly play a role in nitrous oxide emission due to increasing use of nitrogen fertilizers around the world. In this study, emissions of methane and nitrous oxide have been measured in a Thai rice field . Clear patterns of diurnal emission variations of both gases have been observed, which were found to generally follow the diurnal variation of the soil temperature. A detailed explanation is given to explain the occurrence of a methane emission peak at night. The effects of urea fertilization and field draining on emissions of the two gases are discussed. Methane emission from Thai rice fields is estimated to be 3.32 Tg CH4 (2.49 Tg CH4-C) each year, contributing about 3.4% to global methane budget due to rice cultivation. Finally, mitigation options for methane emission from rice fields are put forward. A thesis submitted in partial fulfilment of the requirement for the degree of Master of Science, School of Environment, Resources & Development Thesis (M.Sc.) - Asian Institute of Technology, 1994 Nitrous oxide Methane Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B15790 http://203.159.5.9/ait-thesis/detail.php?q=B15790 050499 20260818112523.0