冻融对土壤氮素损失及有效性的影响

发布时间：2018-08-16 13:39

【摘要】：土壤冻融交替是寒冷生态系统土壤氮素循环的重要驱动力。已有研究表明冻融交替作用能够促进氮素周转,从而缓解因土壤有效氮素缺乏而引起的植物生长限制。即便如此,冻融环境下土壤有效氮素供应量远高于其利用量,过剩的氮素会通过气态(N2O-N)排放、淋溶和径流等途径损失。论述了季节冻融环境和模拟冻融条件下土壤氮素损失状况;同时分析了影响冻融土壤N2O生产的相关因素、产生途径及冻融期N2O大量排放的机制;针对冻融交替过程中土壤氮素有效性问题,探讨了氮矿化、可溶性有机氮(DON)和微生物量氮(MBN)与氮素损失的关系。评述了土壤冻融研究中存在的不足,认为模型研究、土壤微生物功能、氮素转化中间产物、土壤-植物界面过程是未来值得关注和深入探讨的研究方向。
[Abstract]:Soil freeze-thaw alternate is an important driving force of soil nitrogen cycle in cold ecosystem. Studies have shown that alternative freeze-thawing can promote nitrogen turnover and alleviate plant growth constraints caused by soil available nitrogen deficiency. Even so, the available nitrogen supply in frozen and thawed soil is much higher than its utilization, and the excess nitrogen will be lost through gas state (N2O-N) emission, leaching and runoff. The soil nitrogen loss in seasonal freeze-thaw environment and simulated freeze-thaw condition was discussed, and the related factors affecting the production of N2O in freeze-thaw soil were analyzed, and the mechanism of N2O emission during freezing and thawing period was also analyzed. The relationship between nitrogen mineralization, soluble organic nitrogen (DON) and microbial biomass nitrogen (MBN) and nitrogen loss was discussed. The shortcomings of soil freezing and thawing research were reviewed. It was considered that the research direction of model study, soil microbial function, nitrogen transformation intermediate product and soil-plant interface process should be paid more attention to and further discussed in the future.
【作者单位】：中国农业科学院农业环境与可持续发展研究所农业清洁流域团队农业部农业环境重点实验室;中国科学院西北高原生物研究所;北京大学城市与环境学院生态学系地表过程分析与模拟教育部重点实验室;
【基金】：国家水体污染控制与治理科技重大专项(2014ZX07201-009)
【分类号】：S153

【共引文献】