冬季淹水稻田CH_4产生、氧化和排放规律及其影响因素研究

采用静态箱/气象色谱法——田间原位观测和室内培养试验连续一年研究了冬季淹水稻田的CH4产生潜力、氧化潜力和排放通量,以探讨冬季淹水稻田CH4产生、氧化和排放的季节变化规律及其影响因素。结果表明：0~251 d（d表示淹水后天数）,CH4产生潜力逐渐增大,到251 d达最大值,之后逐渐减小;0~204 d,CH4氧化潜力变化较小,但到235 d急剧增至最大值,随后逐渐减小;0~169 d,稻田几乎没有CH4排放,192 d才开始有较明显的CH4排放,到230 d达最大值,为80.2 mg.m-2.h-1,随后逐渐减小,331 d出现一个CH4排放高峰。全观测期内CH4排放量为69.9 g.m-2,其中非水稻生长期排放6.7 g.m-2,占总量的9.5%。全观测期内CH4产生潜力与土温及土壤Eh均无显著相关性;全观测期内CH4氧化潜力与土温极显著正相关（P〈0.01）,水稻生长期CH4氧化潜力与土壤中氨氮含量呈极显著正相关（P〈0.01）;全观测期内稻田CH4排放与土温和CH4产生潜力两个因素均显著正相关（P〈0.05）而与土壤Eh呈显著负相关（P〈0.05）。

Study on the rules of CH4 production, oxidation, and emission and their influencing factors in continuously flooded rice field

Incubation and field experiments were conducted to investigate seasonal variations of CH4 production,oxidation,and emission and their influencing factors in permanently flooded rice fields.Results showed that CH4 production potential increased gradually during the 0-251 d,reached the seasonal peak on 251 d,and thereafter decreased slowly.CH4 oxidation potential varied slightly during the 0-204 d,but sharply increased and reached the seasonal peak on 235 d,and thereafter decreased gradually.Almost no CH4 flux was detected during the 0-169 d.CH4 flux was observed on 192 d,reached the peak value,80.2 mg·m-2·h-1 on 230 d,and thereafter rapidly decreased.Another CH4 flux peak was observed on 331 d.The total CH4 emission was 69.9 g CH4·m-2 in the whole period.CH4 emission was 6.6 g·m-2 during the winter season,about 9.5% of the total.No significant correlations were found between CH4 production potential and soil temperature or soil Eh in the whole period.A significant positive relationship was observed between CH4 oxidation potential and soil temperature in the whole period（P0.01）,and there was a same relationship（P0.01） between CH4 oxidation potential and the content of soil NH4＋ during the rice-growing season.On the other hand,we also found that in the whole period CH4 emission was positively related to the soil temperature and CH4 production potential（P0.05） but negatively related to the soil Eh（P0.05）.