| Based on the mutualistic symbiosis relationship of rice and duck, jointed with no-tillage technique, the new no-tillage system of raising duck in paddyfield was formed. In order to provide the scientific and theoretic foundation for ecological assessment and popularization of the system, some experiments of methane emission, physical and chemical characteristic of soil, soil microbe, soil enzyme and rice growth characteristic were studied. The results were as follows:1.The methane emission characteristic of no-tillage-based rice-duck complex system.1.1 The methane emission dynamics of no-tillage-based rice-duck complex system1.1.1 The daily variation dynamics of methane emission: the daily methane emission which reaches a climax in daytime was almost consistent with the change of air temperature. In the morning, the air temperature was lower so that the methane emission was lower. With the increase of the air temperature, the methane emission also increased gradually. At about 12:00-14: 00, the emission reached a climax, and then declined. Till the dawn, it was the lowest. The dissolved oxygen in NCD(No-tillage Cast-transplanted with Duck treatment)system has increase greatly, compared with the NCND (No-tillage Cast-transplanted without Duck treatment ) and the CCND (Conventional-tillage Cast-transplanted without Duck treatment) ,? it increased 38.4%-44.7%, which was helpful to the methane oxidation.1.1.2 The seasonal variation dynamics of methane emission: In wetlands system, during the late rice growth period, the emission was lower at early tillering stage. At fully tillering stage, it reached its summit, since then, with the rice growth, it reduced. After booting stage , the methane emission keeped lower.The difference among the NCD, NCND and CCND was obvious, but it was not between the NCND and CCND. the average methane emission trend was: NCD |
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