氮肥对黄壤温室气体排放和玉米产量的影响

Effects of Nitrogen Fertilizer on Greenhouse Gas Emissions and Maize Yield in Yellow Soils

为比较不同氮肥施用量对农田温室气体排放强度、玉米产量、全球增温潜势及温室气体排放强度的影响,正确认识氮肥在农田温室气体排放的贡献,为化肥减量增效,玉米增产稳产,降低综合温室效应,实现农业可持续发展提供科学依据,采用大田试验,以玉米为供试作物,设置当地传统施肥(CF100)、氮肥减量30%(CF70),氮肥减量50%(CF50)和不施肥(CK)4个处理,采用静态箱—气相色谱法测定贵州典型黄壤玉米生长季,分析不同施氮梯度下作物产量和温室气体排放特征.结果表明,与CK相比,施氮处理均提高了CO_(2),CH_(4)和N_(2)O的平均排放通量和累积排放量,但是施氮处理之间差异均无统计学意义.全球增温潜势(GWP)在CF50,CF70,CF100处理下分别显著增加了36.78%,52.14%和50.22%,三者之间差异无统计学意义.施用氮肥显著增加玉米产量,CF100与CF70产量无显著差异,与CF50相比,分别显著增加了16.33%和13.53%(p<0.05).温室气体排放强度(GHGI)在CF50,CF70,CF100处理下分别显著降低了57.88%,60.15%和60.94%,但是施氮处理之间差异无统计学意义.施氮处理可降低土壤pH值、增加土壤全氮(TN)、全磷(TP)质量分数,而有机碳质量分数呈先增后减趋势.施用氮肥会增加温室气体的排放,但可显著提高作物产量.从产量和GHGI角度来看,CF70与CF100产量、GHGI差异均无统计学意义(p>0.05).因此,为实现较高的玉米产量和较低的温室气体排放,实现化肥减量增效,氮肥减量30%的施肥方式符合该区农业可持续发展目标.

To explored the effects of different rates of nitrogen fertilizer on the greenhouse gas(CO_(2),CH_(4) and N_(2)O)emissions,maize yield,global warming potential and greenhouse gas emission intensity,understand the contribution of nitrogen fertilizer to the greenhouse gas emissions,provide scientific basis for stabilizing production,reducing the comprehensive greenhouse effect,and realize the sustainable development of agriculture.In the field experiment,maize was used as the test crop.Four nitrogen application rates were set up,including the local traditional fertilization(CF100),30%reduction in nitrogen fertilizer(CF70),50%reduction in nitrogen fertilizer(CF50)and no fertilization(CK).The static chamber-gas chromatography method was used to determine the greenhouse gas fluxes during the maize growing.The crop yields of different nitrogen application rates for the typical yellow soil in Guizhou were measured at harvest.Compared to CK,nitrogen application increased the average emission flux and cumulative emission of CO_(2),CH_(4) and N_(2)O,but there was no significant difference among the nitrogen application treatments.The global warming potential(GWP)increased significantly by 36.78%,52.14%and 50.22%under the treatment of CF50,CF70 and CF100,respectively.The application of nitrogen fertilizer significantly increased the yield of maize.There was no significant difference between CF100 and CF70.Compared to CF50,the yield of CF100 and CF70 was increased by 16.33%and 13.53%,respectively(p<0.05).Greenhouse gas emission intensity(GHGI)was significantly reduced by 57.88%,60.15%and 60.94%under CF50,CF70 and CF100 treatments,respectively,but there was no significant difference among nitrogen application treatments.Nitrogen application treatment could decrease soil pH value and increase the contents of soil total nitrogen(TN)and total phosphorus(TP).The content of organic carbon increased first and then decreased.Application of nitrogen fertilizer could increase the greenhouse gas emissions,but can significantly increase the crop yield.There were no significant differences in grain yield and GHGI between CF70 and CF100 treatments(p>0.05).Therefore,to achieve high maize yield and low greenhouse gas emissions,the 30%of fertilization reduction based on the application of local traditional nitrogen fertilizer would be the management to achieve the sustainable agriculture development.