稻-鸭复合系统中灌水深度对甲烷排放的影响

以稻田养鸭和稻田蓄水2项经典农作技术为背景，研究了稻-鸭复合系统中不同灌水深度对甲烷排放的影响以及深水灌溉下土壤氧化还原特性对甲烷排放的影响．结果表明，灌水20，10cm与灌水5，2cm处理之间甲烷排放通量差异显著；4个处理全生育期CH4排放总量分别为6．28，6．36，7．23，7．30g／m^2，灌水处理期间CH4排放量分别为1．19，1．24，2．31，2．37g／m^2，灌水20cm的CH4排放量分别是其他处理的95．9％，51．5％，50．2％．深灌导致土壤氧化还原电位略降低，灌水20cm土壤氧化还原电位比2cm处理低8．2mV．相关分析表明，甲烷排放通量与土壤氧化还原电位相关性不显著，与还原物质总量、活性还原物质总量呈正相关．

Effect of Irrigation Depths on Methane Emission in Rice-Duck Complex Ecosystems

Based on techniques of rice-duck cultivation and storing water in the rice paddy fields,in order to provide a practical and theoretic foundation for the model of rice-duck symbiosis,effects of different irrigation depths on CH4 emission in the rice-duck complex system are studied in this experiment.Results showed that there exist significant differences between CH4 emission fluxes at the irrigation depths of 20 cm,10 cm,5 cm and 2 cm.Total amount of methane emission in the whole early rice season were 6.28,6.36,7.23,7.30 g/m2 at irrigation depth of 20 cm,10 cm,5 cm and 2 cm respectively and during the irrigation treatment were 1.19,1.24,2.31,2.37 g/m2,respectively.Methane emission irrigated 20 cm deep accounts for 95.9%,51.5%,50.2% of other irrigation treatments,respectively.Deep irrigation led to reduce the soil Eh slightly and soil Eh of irrigation 20 cm reduced by 8.2 mV comparing with the irrigation 2 cm.According to the results of correlative analysis,correlation between methane emission and soil Eh was not significant,but significant positive correlation existed between methane emission and the total redox matter and active redox matter.