猪粪沼液施用对稻田CH4和N2O排放及温室效应的影响

为解决规模养殖废弃物超排引起环境污染严重且资源大量浪费的问题,采用静态箱-气相色谱法,研究猪粪、沼液替代化肥条件下稻田CH4和N2O排放特征,并运用全球增温潜势(GWP)的方法对稻田CH4和N2O排放的温室效应进行估算。研究结果表明:与常规施肥相比,尽管猪粪替代化肥措施均显著(P<0.05)降低稻田N2O排放,但以100%或50%猪粪替代化肥处理仍显著(P<0.05)增加了稻田GWP及单位产量的GWP,分别提高了385.5%、218.2%和422.4%、228.4%,主要是由于猪粪替代化肥处理不仅改变了CH4排放规律,还显著增加了(P<0.05)稻田CH4排放。而采用100%或50%沼液替代化肥措施减少了稻田GWP及单位产量的GWP,分别降低了27.8%、15.4%和29.5%、18.8%,主要是由于沼液替代化肥处理显著降低了(P<0.05)稻田N2O排放。就综合温室效应而言,采用沼液替代化肥能够有效降低养殖排泄物稻田施用产生的温室效应。

Effects of pig manure and biogas slurry application on CH4 and N2O emissions and their greenhouse effects on paddy field

In order to treat waste superovulation by the large-scale cultivation in Jiangsu Province,which may cause serious environmental pollution and a massive waste of nutrient resource,emissions of CH₄ and N₂O from the paddy fields were measured in situ by using the method of static chambers and gas chromatographic techniques,and the greenhouse effect of CH₄ and N₂O was assessed by using global warming potential (GWP).The field experiment results clearly demonstrated that the GWP and GWP per unit yield were significantly increased by 385.5% and 422.4% under pig manure (100% PM) treatment,and by 218.2% and 228.4% under half pig manure and half chemical fertilizer (50% PM) treatment compared to chemical fertilizer (NPK) treatment,respectively.This can be explained that the value of CH₄ emission from 100% PM and 50% PM treatments was significantly greater than that from NPK treatment,although the emissions of N₂O from the paddy fields were significantly lower for 100% PM and 50% PM than that for NPK treatment.While,compared with NPK treatment,the values of GWP and GWP per unit yield were decreased by 27.8% and 29.5% under biogas slurry (100% PS) treatment,and by 15.4% and 18.8% under half biogas slurry and half chemical fertilizer (50% PS) treatment,respectively.Mainly for the reason that lower N₂O emissions were obtained under 100% PS and 50% PS treatments compared with NPK treatment.As far as GWP,lower greenhouse effects are obtained in 100% PS and 50% PS treatments,while the breeding waste is reused in paddy fields in the rice-wheat rotation system.