爽水性稻田甲烷排放特点

通过田间小区试验 ,观测研究了不同施氮水平和前茬是否施用稻草的爽水性稻田的甲烷排放情况。结果表明 ,爽水性稻田甲烷排放通量有明显的规律性 ,烤田前甲烷排放量较大 ,烤田期间甲烷排放并不明显减少 ,但烤田后甲烷排放下降显著 ;前茬覆盖稻草对稻田甲烷排放有明显的促进作用 ;水稻整个生育期稻田的氧化还原电位与甲烷排放通量有一定的相关性 ;爽水性稻田甲烷排放出现两种类型的日变化 ;尿素用量对甲烷排放量没有明显的相关性 ;水稻产量高低与甲烷排放之间有一定的相关性。

Methane Emission from Permeable Paddy Soils in Jiangsu Province

Methane emission from permeable paddy soils amended with different dosage of urea and ricestraw at the preceding winter wheat was investigated in hilly area of Jurong, Jiangsu province in 1997. The average methane flux was the highest before mid-season aeration and the flux did not significantly decrease during the aeration, but the flux was small after the aeration. The application of ricestaw at the preceding winter wheat strongly enhanced the methane emission from the rice field. In whole rice growth, the total methane emission was correlated to soil Eh, but was not significantly related to the urea application rate. The yields of ricestraw above the ground and rice grain were evidently correlated to total methane emission in the parabola equations. Two types of methane emission day_variation were observed from the research.