Laws of methane production in paddy soil in red earth hilly area of South China

Studies on laws of methane production in paddysoil have been carried out and the results show that(1) tempera-ture has a significant influence on methane production andmethane production rates increase by about 3 times with a rise of 10℃in temperature;(2)two peaks of methane production ap-pear after transplantation and before harvest respectively for bothearly rice and late rice,methane production rates are lower atmiddle growing stage ;(3)vertical distribution of methane pro-duction rates in paddy soil coincides with that of organic acid contents;(4) methane production rates in paddy soil with rice plants are much higher than those without rice plants and the dif-ference is getting more and more significant with the tice growth;(5)more than 80 % of the methane produced in paddy soil is re-oxidized in the course of transportation to the atmosphere i.e. less than 20%of the methane can be emitted to the atmosphere.