ABSTRACT
This chapter provides results of the simultaneous measurements of emission, production, and oxidation of methane (CH4) in a Japanese rice paddy field during an entire cultivation period. It focuses on seasonal changes of CH4 production and oxidation in different depths of paddy soil, and their relationship to CH4 emission, in order to understand factors controlling this process in paddy fields. A field study was carried out in an experimental paddy field of the Ryugasaki Branch of the Ibaraki Agricultural Experiment Station during the 1991 growing season. The soil of the paddy field is classified as Gley soil. The closed chamber method was used for the measurements of the CH4 emissions from paddy fields into the atmosphere. Temperature of air and paddy soil at the depths of 0, 2, 5, and 10 cm was continuously recorded during the cultivation periods by using Pt-resistance thermometers and a data logger.
