氮沉降和施生物质炭对毛竹林土壤N2O通量的影响

本研究于2019年7月—2020年7月在浙江省杭州市典型毛竹林布置野外控制实验,采用静态箱-气相色谱法测定毛竹林土壤N₂O通量,分析生物质炭(10 t·hm^-2)、氮沉降(60 kg N·hm^-2·a^-1)、生物质炭+氮沉降混合处理对土壤N₂O通量的影响,并探讨了土壤N₂O通量与环境因子的关系。结果表明: 与对照相比,氮沉降处理使毛竹林土壤N₂O年累积排放量增加了14.6%,而施用生物质炭及其与氮沉降混合处理则分别降低了20.8%和10.6%。相关分析表明,在所有处理下,毛竹林土壤N₂O排放速率与土壤温度、硝态氮含量、脲酶和蛋白酶活性之间均呈极显著相关,与土壤铵态氮含量均呈显著相关。在氮沉降背景下,施用生物质炭对毛竹林土壤N₂O通量仍具有显著的减排效应。

Effects of nitrogen deposition and biochar application on soil N2O fluxes in a Moso bamboo plantation

In July 2019-July 2020, we conducted a field trial to examine the effects of nitrogen addition (60 kg N·hm^-2·a^-1), biochar application (10 t·hm^-2), and their combination on soil N₂O emission and the relationship between soil N₂O emission and environmental factors in a typical Moso bamboo (Phyllostachys edulis) plantation in Hangzhou City of Zhejiang Province. Soil N₂O flux of Moso bamboo plantation was measured by the static chamber-gas chromatography technique. The results showed that nitrogen addition treatment increased the annual cumulative N₂O emission by 14.6%, while biochar application and the combination treatment reduced it by 20.8% and 10.6%, respectively. Soil N₂O flux rate was significantly correlated with soil temperature, NO₃^--N concentration, urease and protease activities, and soil NH₄⁺-N concentration across all treatments. In conclusion, under the background of nitrogen deposition, the application of biochar would have a significant reduction effect on soil N₂O fluxes in Moso bamboo plantations.