稻田施用沼渣对甲烷排放通量的影响

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

通过网室小区试验，观测得出：（１）４种沼渣处理和单施化肥处理的一季稻田平均甲烷排放通量为０．５６９～２．１８８ｍｇ０￣２·ｈ，两者无显著差异；农家肥处理稻田的平均甲烷排放通量为４４．１８ｍｇ／ｍ￣２·ｈ显著高于前两种处理，表明施用沼渣和化肥比施用农家肥能显著减少稻田甲烷排放量；（２）各处理稻田甲烷排放通量峰值期部出现在水稻蘖期至拔节初期，表明这一时期是控制稻田甲烷排放总量的关键时间；（３）各处理甲烷排放通量分别与淹水前各处理土壤及供试有机肥的易矿化碳含量、ＣＨ＿４－Ｃ含量呈显著正相关关系，这表明土壤易矿化碳含量是形成稻田甲烷的重要条件；（４）各处理之间水稻产量没有明显差异。

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/m￣2·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/m￣2·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 CH_4-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 pad-