负载NH4+-N生物炭对土壤N2O-N排放和NH3-N挥发的影响

利用生物炭吸附面源污染水体NH₄⁺-N并将其进行还田可实现此氮资源由水体到农田的安全有效迁移，而探索负载NH₄⁺-N生物炭对N₂O-N排放和NH₃-N挥发的影响则对于减施化肥和降低土壤氮素损失意义重大.本研究采用土柱试验，设置4个处理：对照（不施氮肥，CK）、单施化肥（NPK）、负载氮+化学磷钾肥（N-BC+PK）和生物炭+化肥（BC+NPK）.结果表明，相较NPK和BC+NPK处理，N-BC+PK处理N₂O-N累积排放量、NH₃-N累积挥发量、气态氮素累积损失量（以N计）分别显著降低了33.62%和24.64%、70.64%和79.29%、64.97%和73.75%（P<0.05）.特别需要说明的是，BC+NPK处理相比NPK处理显著增加了NH₃-N累积挥发量（P<0.05）.综上所述，负载NH₄⁺-N生物炭可显著减少N₂O-N排放和NH₃-N挥发，且其减排效果显著优于传统的生物炭化肥配施.本研究结果将为富营养化水体NH₄⁺-N农田回用和土壤气态氮素减排提供理论依据和数据支持.

Gaseous Nitrogen Emission from Soil After Application of NH4+-N Loaded Biochar

To safely and effectively transfer NH₄⁺-N from eutrophic water to soil, biochar was applied to adsorb NH₄⁺-N from wastewater, and this NH₄⁺-N loaded biochar (N-BC) was subsequently used as a soil amendment. Understanding the influence of N-BC on N₂O-N emission and NH₃-N volatilization is important for both decreasing the application of chemical fertilizers and reducing gaseous nitrogen loss from soil. In this study, experiments were conducted in soil columns with four treatments, namely CK (no fertilizer), NPK (chemical fertilizer), N-BC+PK (NH₄⁺-N loaded biochar+chemical fertilizer), and BC+NPK (biochar+chemical fertilizer). Compared to both the NPK and BC+NPK treatments, N-BC+PK significantly reduced the cumulative N₂O-N emissions and NH₃-N volatilization, as well as the total gaseous nitrogen loss from the soil (P<0.05). Relative to NPK and BC+NPK, cumulative N₂O-N emissions decreased by 33.62% and 24.64%, cumulative NH₃-N volatilization decreased 70.64% and 79.29%, and the cumulative total gaseous nitrogen loss decreased by 64.97% and 73.75%. In particular, BC+NPK significantly enhanced the cumulative NH₃-N volatilization. Furthermore, the N₂O-N emission flux and NH₃-N volatilization rate were significantly positively correlated with the NH₄⁺-N concentration, NO₃^--N concentration, and pH of soil (P<0.01). Overall, using NH₄⁺-N loaded biochar can significantly decrease N₂O-N emissions and NH₃-N volatilization, relative to the traditional application combining biochar and chemical fertilizer. This research provides solid theoretical support and data for the application of NH₄⁺-N loaded biochar in soil, to reduce gaseous nitrogen loss.