Effect of appllilg biogas pit sedinient on niethane eniissionfluxes from paddy fleld

Some conclusions were drawn from plot exper-iments.（1） Average methane ecission flux ,which was single cropping paddies applied with four kinds of biogas pit sediment and only chemical fertilizer separately,was in the range of 0.569-2.188mg/m²·h.There was not singnificant difference between the two treatments.Average methane emission flux ,which was single cropping paddies treated with manures,was 44.18mg/m²·h .The result of the latter was higher than that of the former,it showed that applied biogas pit sediments and chermical fertilizers can reduce obviously menthane emission fluxes from cropping pdddies.（ 2） Peak stage of methane emis-sion fluxe frorn each treatment paddy appeared from tillering stage to early jointing stage,it showed that this was the key peried for controlling the total methane emission from pad-dies.（ 3） The Tnethane emission flux was significantly and pos-itively correlated with the contents of readily mineralizable carbon（RMC）and CH₄-C in the soils and organic fertilizers before flooding,it suggested that RMC was the important fac-tor for forming methane form paddies.（4）There were not ob-vious differences among the rice yields of each treatment paddy.