生物质炭对华北平原4种典型土壤N2O排放的影响

生物质炭作为一种新型的土壤改良剂,在降低土壤温室气体排放方面发挥着重要作用.为明确生物质炭对冬小麦苗期土壤N_2O排放的影响,以华北平原的4种典型土壤(水稻土、砂姜黑土、褐土和潮土)为研究对象,进行田间试验,设置了4个处理:对照(CK)、单施化肥(NPK)、单施生物质炭(BC)和化肥与生物质炭配施(NPK+BC).结果表明,单施化肥显著增加了4种土壤N_2O排放,与对照相比,水稻土、砂姜黑土、褐土和潮土N_2O排放分别增加了314%、116%、240%和282%.添加生物质炭对华北平原4种土壤N_2O排放影响存在差异,与CK相比,单施生物质炭水稻土、褐土N_2O排放显著增加了72. 4%和50. 9%,而砂姜黑土和潮土BC与CK处理无显著差异.与NPK相比,生物质炭与化肥配施显著降低了4种土壤N_2O排放.添加生物质炭提高了4种土壤pH,其中,初始pH最低的水稻土,受生物质炭影响较显著,施肥则降低了4种土壤pH.砂姜黑土、褐土和潮土施肥处理N_2O排放通量均与铵态氮含量呈显著正相关,水稻土和砂姜黑土单施生物质炭处理N_2O排放通量与硝态氮含量呈显著正相关.

Effects of Biochar on N2O Emission from Four Typical Soils in the North China Plain

As a potential soil conditioner, biochar plays an important role in alleviating greenhouse gas (GHG) emissions. To clarify the influence of biochar on soil N₂O emissions during the winter wheat seedling stage, four typical soils in the North China Plain (paddy soil, shajiang black soil, cinnamon soil, and fluvo-aquic soil) were adopted for field experiments, and four treatments were set:Control (CK), Fertilizer (NPK), Biochar (BC), and Fertilizer+Biochar (NPK+BC). The results showed that fertilization (NPK) significantly increased the N₂O emissions of the four soils. Compared with that of the CK, the N₂O emissions of four soils were increased by 314%, 116%, 240%, and 282%, respectively. The effect of biochar addition on N₂O emissions of the four soils in the North China Plain was different. Compared with that of the CK treatment, the N₂O emissions of paddy soil and cinnamon soil in the BC treatment significantly increased by 72.4% and 50.9%, respectively, whereas the shajiang black soil and fluvo-aquic soil exhibited no significant differences. The combined application of biochar and fertilizer significantly reduced the N₂O emissions of the four soils, compared to that of NPK. The addition of biochar increased the pH of soil. In particular, paddy soil had the lowest initial pH and was most affected by biochar. Fertilization reduced the pH of the four soils. N₂O flux under fertilizer treatment for the shajiang black soil, cinnamon soil, and fluvo-aquic soil was significantly positively correlated with ammonium nitrogen content, whereas N₂O emission fluxes under single biochar treatment on paddy soil and shajiang black soil were significantly positively correlation with nitrate nitrogen content.