沼液替代化肥对麦季CH4、N2O排放及温室效应的影响

采用遮光密闭箱和气相色谱法,研究了化肥、化肥＋稻草、50%沼液＋50%化肥、100%沼液4个处理下麦季CH4和N2O的排放特征,并运用全球增温潜势（GWP）对麦季CH4和N2O排放的温室效应进行了估算。研究结果表明,与化肥处理相比,化肥＋稻草处理显著（P〈0.05）提高了麦季CH4和N2O排放通量,使其所产生的GWP及单位产量的GWP显著（P〈0.05）增加,分别提高了57.90%和52.00%;而100%沼液、50%沼液替代化肥处理减少了麦季GWP及单位产量的GWP,分别降低了25.39%、10.88%和24.16%、10.97%,主要是由于沼液处理降低了麦季N2O排放总量。可见,稻麦轮作条件下沼液替代化肥措施会降低稻茬麦季的综合温室效应。

Effects of Chemical Fertilizers Substitution by Biogas Slurry on CH4 and N20 Emissions and Their Greenhouse Effects in Wheat Field

Emissions of CH4 and N20 from the wheat fields were measured in situ using the method of static chambers and gas chromatograph- ic techniques, and the greenhouse effect of CH4 and N20 were assessed by using global warming potential（GWP）. The field experiments results clearly demonstrated that the emissions of CH4 and N20 from the wheat fields were significantly greater for chemical fertilizer with straw treat- ment than that for chemical fertilizer treatment. Moreover, the GWP and GWP per yield were significantly increased with chemical fertilizer with straw treatment compared to chemical fertilizer treatment by 57.90% and 52.00%, respectively. While, compared with chemical fertilizer treatment, the values of GWP and GWP per yield were decreased by 25.39% and 24.16% under biogas slurry treatment, and by 10.88% and 10.97% under half biogas slurry with half chemical fertilizer treatment, respectively. This could be explained that lower N20 emissions were obtained under biogas slurry and half biogas slurry with half chemical fertilizer treatments contrasted to chemical fertilizer treatment, in addi- tion, lower greenhouse effects of CH4 and N20 emissions were obtained in biogas slurry and half biogas slurry with half chemical fertilizer treatments in contrast to chemical fertilizer and chemical fertilizer with straw treatments during wheat season in the rice-wheat rotation sys- tem.