茶园氧化亚氮排放机制及减排措施研究进展

Nitrous Oxide Eemission Mechanism and Emission Mitigation Measures of Tea Plantation:A Review

茶园因氧化亚氮(N2O)排放系数大、氮肥施用量高及种植面积逐年增加,成为我国农业重要的N2O排放源,因此迫切需要研究茶园N2O排放机理及有效的减排措施。目前,关于不同农学措施对茶园N2O排放特征的影响研究较多,但其N2O减排效果尚无定论,该研究综合分析不同农学措施对茶园N2O排放的影响及其机制,希望为进一步开展茶园N2O减排研究提供理论和实践参考。通过综述发现:茶园排放的N2O主要源于土壤硝化和反硝化过程,其中反硝化作用引起的N2O排放更多;影响茶园N2O排放的因素主要有气象因子(温度、降雨)和土壤条件(pH、含水量、质地、温度、底物浓度);茶园有效的N2O减排措施主要为施用铵态氮肥、控释氮肥和石灰氮以及氮肥深施;施用有机肥、施用生物硝化抑制剂、添加碱性材料、添加生物质炭、间种豆科植物及施用生物肥料的N2O减排效果尚存在分歧,需开展进一步研究。

Tea plantation has become an important source of agricultural nitrous oxide(N2O)emission in China due to high N2O emission factor,high application of nitrogen fertilizer and increasing planting area year by year.In 2013,the total N2O emission of tea plantations in China was estimated to be 40.90 Gg.Therefore,it is urgent to study the N2O emission mechanism and effective emission reduction measures of tea plantations.With the deepening of research on N2O emission process and influencing factors in tea plantations,many summarized emission reduction strategies are regarded as effective measures to mitigate N2O emission in tea plantations.Through the review,we found that:(1)the N2O emissionfrom tea plantations is mainly caused by soil nitrification and denitrification,and the later contricutes more;(2)the main factors affecting N2O emission in tea plantations are meteorological factors(temperature,rainfall)and soil conditions(pH,moisture content,texture,temperature,substrate concentration);(3)effective N2O emission mitigation measures in tea plantations mainly include the application of ammonium nitrogen fertilizer,controlled release nitrogen fertilizer,lime nitrogen fertilizer and deeply placing of nitrogen fertilizer;(4)there are still different opinions in the N2O emission reduction effects among applying organic fertilizer,applying biological nitrification inhibitors,adding alkaline materials,adding biomass charcoal,interplanting leguminous and applying biological fertilizers,which need to be further studied.At present,there are many researches on the influence of different agronomic measures on N2O emission characteristics in tea plantation,but there is no agreement on the effect of N2O emission reduction.This paper comprehensively analyzes the effect and mechanism of different agronomic measures on N2O emissionin tea plantation,hoping to provide theoretical and practical references for further research on N2O emissions mitigation in tea plantation.