An Observational Study of Methane Emission of Rice Paddies in Zhenjiang Lin’an

Methane (CH4) flux from rice paddies was observed in Lin’an (34°14′N, 119°42′E) of Zhejiang province by using the static chamber during July through September 1990. Methane flux in the range of 3.67—16.14mg/m2·h was obtained during the irrigating period. The averaged methane emission flux is 10.58mg/m2·h. The CH4 release rates are shown that there is a strong diurnal variation with a maximum value at night or in the early morning and a minimum value in daytime. A seasonal variation of CH4 flux from rice paddies exhibites a rapid rising from rice plant tilling to heading periods. Then, CH4 emission decreases with water level in the rice paddies. In addition, methane emission is also related to the natural conditions, such as temperature, wind speed and rain