不同氮肥对东北春玉米农田温室气体周年排放的影响

为探明不同氮肥条件下高纬度农田土壤的温室气体排放特性,采用静态箱-气相色谱法研究了常规施氮(CN)、施用缓释肥(SLN)、尿素添加硝化抑制剂和脲酶抑制剂(NIUI)、不施氮肥(NN)对东北春玉米农田土壤温室气体排放的影响.结果表明: CN、SLN和NIUI处理产量分别为9618、9376和9645 kg·hm^-2.与CN处理相比,SLN促进了玉米生长季土壤N₂O的排放,降低了非生长季土壤N₂O的排放;NIUI处理N₂O累积排放量比CN降低了39.0%;各处理土壤CO₂周年累积排放通量无显著差异;东北春玉米田是大气中CH₄的弱汇,NIUI处理较CN促进了玉米生长季土壤对CH₄的吸收.综上,尿素添加脲酶抑制剂和硝化抑制剂可以在实现玉米高产的同时有效减少土壤温室气体排放.

Effects of different nitrogen fertilizers on annual emissions of greenhouse gas from maize field in Northeast China

A field experiment was conducted to investigate the greenhouse gas emission at high latitude farmland in Northeast China. We monitored the greenhouse gas emission using the static chamber-gas chromatography method. Four nitrogen (N) fertilizers were used: conventional N fertilization (CN), slow release fertilizer (SLN), urea plus nitrification inhibitor and urease inhibitor (NIUI), and no nitrogen fertilizer (NN). The results showed that the yields under CN, SLN and NIUI treatments were 9618, 9376 and 9645 kg·hm^-2, respectively. Compared with CN treatment, SLN increased soil N₂O emission in the growing season and decreased N₂O emission in the non-growing season. The cumulative N₂O emission flux of NIUI treatment was 39.0% lower than that of CN. There were no significant differences in the annual cumulative CO₂ emission flux among the treatments. The spring maize field in Northeast China was a weak CH₄ sink. NIUI treatment promoted soil CH₄ absorption in maize growing season compared with CN treatment. In summary, urea plus nitrification inhibitor and urease inhibitor could significantly reduce soil greenhouse gas emissions with high yield of maize.