沼液施用对土壤温室气体排放的影响

Biogas slurry application with greenhouse gas emissions in agricultural soils

采用静态箱-气相色谱法,于2010年7月(夏季)、2011年3月(冬季)进行了不同沼液施用量对土壤二氧化碳(CO2),甲烷(CH4)和氧化亚氮(N2O)气体排放影响的研究。试验期间,沼液施用设为大量施沼液(夏季为28.36 g.m-2,冬季为1.94 g.m-2),正常施沼液(夏季为9.45 g.m-2,冬季为0.65 g.m-2)和不施沼液等3个水平。结果表明:①夏季或冬季,处理对土壤二氧化碳排放影响均不显著。②夏季沼液施用8 h内,处理间对土壤甲烷排放具极显著差异(P<0.001),其中大量施沼液时通量最大为3.98 mg.m-2.h-1;正常施沼液时通量最大为1.25 mg.m-2.h-1,8 h后处理间无显著差异(P>0.05)。冬季在大量施沼液时,初期土壤甲烷排放通量明显高于正常施沼液及不施沼液,最大为0.28 mg.m-2.h-1;随后处理间土壤甲烷排放通量无显著差异。③夏季沼液施用20 h内,处理间对土壤氧化亚氮排放具极显著差异(P<0.001),最大值达1 641μg.m-2.h-1;处理间呈显著差异(P<0.05),大量施沼液、正常施沼液和不施沼液时土壤氧化亚氮排放通量分别为224～349,70～137,33～57μg.m-2.h-1;冬季则处理间土壤氧化亚氮排放无显著差异。

To determine the effects of biogas slurry application on greenhouse gas emissions （GGE）, including CO2, CH4, and N=O, in agricultural soil, a closed-chamber, gas chromatography-based system were used in July 2010 （summer） and March 2011 （winter）. Three treatments with 3 replications were carried out： no （ck）, normal （9.45 g.m-2 in summer, and 0.65 g.m-1,in winter）, and heavy （28-36 g-m-2 in summer, and 1.94 g m-2 in winter） biogas slurry applications. Two-way ANOVA analysis was used to test the significance. Results showed （1） no significant differences in CO2 emissions among treatments. （2）For CH4 emissions in summer with- in the first 8 h of biogas slurry application, the heavy application treatment was significantly greater （P〈O.001） than the other two treatments with a maximum emission flux of 3.98 mg. m-2. h-I in the heavy, 1.25 mg. m-2.h-1 in the normal, and 0.28 mg m-1 E h-1 in ck; however, after 8 h there were no significant differences. （3） NzO emissions in summer within the first 20 h after biogas slurry application, revealed significant differences （P〈 0.001） with a maximum emission flux of 1 641 μg.m-2.h-1 in the heavy application treatment; after 20 h, significant differences （P〈0.05） between the treatments continued with the NEO emission fluxes of 224-349 μg m-2.h-l for heavy, 70-137 μg.m-2.h-1 for normal, and 33.81-57.06 μg.m-2.h-1 for ck. No significant differ- enees in N20 emissions were found between the treatments in winter. These results could provide helpful infor- mation for environmental risk assessments with biogas slurry application, especially with effects on GGE. [ Ch, 3 fig. 19 ref. ]