Abstract:

To study the temporal effect of biochar on greenhouse gas emissions， the soil of the Huang-Huai-Hai plain was as the research object. The amount of biochar was added with 0.00 （CK）， 2.25 （C1），4.50 （C2），9.00 （C3），13.50 t·hm^-2 （C4） per year and 13.50 t·hm^-2 （CS） at one time for 3 years. The differences in soil greenhouse gases and soil physicochemical properties of the wheat-maize rotation farmland ecosystem in the Huang-Huai-Hai plain were studied. The results showed that CS treatment could significantly suppress CO₂ emission of soil， with the decrease of 38.5% and 25.75% in wheat and corn seasons， respectively. The C2， C3 and C4 treatments significantly suppressed CO₂ emission of soil by 17.7%~24.6% in the maize season. Biochar had no significant effect on CH₄ emission of soil. The application of biochar could significantly inhibit N₂O emission of soil， reaching 37.5%~60.1% and 24.9%~39.3% in wheat and maize seasons， respectively. Only CS treatment significantly reduced the comprehensive warming potential by 30.4%， which indicated that the one-time application of a large amount of biochar had a better inhibitory effect on greenhouse gases. Correlation analysis showed that soil CO₂ emission flux was significantly positively correlated with soil temperature， moisture， NH{}_{\mathrm{4}}^{+}-N and NO{}_{\mathrm{3}}^{-}-N. Soil CH₄ emission flux was negatively correlated with soil temperature， moisture， NH{}_{\mathrm{4}}^{+}-N and NO{}_{\mathrm{3}}^{-}-N. Soil N₂O emission flux was positively correlated with soil temperature， moisture， NH{}_{\mathrm{4}}^{+}-N and NO{}_{\mathrm{3}}^{-}-N. In summary， biochar could inhibit soil greenhouse gas emissions. Under the conditions of this experiment， a one-time application of 13.5 t·hm^-2 of biochar could maximize environmental benefits.

Key words: physical and chemical properties of soil, global warming potential, biochar, time-dependent

摘要：

为研究生物炭对温室气体排放影响的时间效应，以黄淮海平原土壤为研究对象，设置每年分别施用0.00（CK）、2.25（C1）、4.50（C2）、9.00（C3）、13.50 t·hm^-2（C4）生物炭和仅一次性施用13.50 t·hm^-2生物炭处理（CS），研究3年后黄淮海平原小麦-玉米轮作农田生态系统土壤温室气体排放及土壤理化性质的差异。结果表明，CS处理可以显著抑制土壤CO₂排放量，在小麦季和玉米季分别较CK显著降低38.5%和25.75%；C2、C3和C4生物炭处理仅在玉米季显著抑制土壤CO₂排放，较CK降低17.7%~24.6%。生物炭对土壤CH₄排放无显著性影响。生物炭处理均可以显著抑制土壤N₂O排放，在小麦季和玉米季分别较CK显著降低37.5%~60.1%和24.9%~39.3%。CS处理显著降低了综合增温潜势，较CK降低30.4%，表明一次性施用大量生物炭对温室气体排放的抑制效果更佳。相关分析表明，土壤CO₂排放通量与土壤温度、湿度、NH{}_{\mathrm{4}}^{+}-N和NO{}_{\mathrm{3}}^{-}-N呈极显著的正相关关系；土壤CH₄排放通量与土壤温度、NH{}_{\mathrm{4}}^{+}-N、NO{}_{\mathrm{3}}^{-}-N呈极显著的负相关关系，与土壤湿度呈显著的负相关关系；土壤N₂O排放通量与土壤温度、湿度、NH{}_{\mathrm{4}}^{+}-N和NO{}_{\mathrm{3}}^{-}-N呈极显著的正相关关系。综上所述，生物炭对土壤温室气体排放具有抑制作用，在本试验条件下，一次性施用13.5 t·hm^-2生物炭可达到环境效益最大化。

关键词: 土壤理化性质, 综合增温潜势, 生物炭, 时间限制效应