Effects of rice straw application during the wheat season on production, oxidation and emission of CH4 during the following rice growing season.

Laboratory incubations and field experiments were carried out to study the effects of rice straw application in wheat season in 2007 on CH4 production potential,CH4 oxidation potential,and CH4 flux from the paddy field during the following rice-growing season in 2008.The results indicated that CH4 oxidation potential in treatment SA(straw application)was significantly higher than that in treatment NS(no straw)at 19th day after rice transplantation,while no significant differences were observed in CH4 production potential and CH4 flux between the two treatments at the early rice growth stage.During the middle rice growth stage,no significant difference in CH4 oxidation potential was observed between the two treatments,both CH4 production potential and CH4 flux in treatment SA were significantly higher than those in treatment NS.The CH4 production potential in treatment SA was 2~4 times that in treatment NS.At the end of the rice growth stage,there were no significant differences were observed between the two treatments in production,oxidation,and emission of CH4.The CH4 emissions mainly occurred in the middle rice growth stage.The total CH4 emission in treatment SA was 1.4 times that in treatment NS in the whole rice season.