The influence of trigger events on bursts of soil microbial metabolism and N2O production and consumption

触发事件对土壤微生物代谢爆发和N2O产生和消耗的影响

• 批准号: RGPIN-2015-03746
• 负责人: Burton, David
• 金额: $ 1.97万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=634151
• 关键词: influence; trigger; events; bursts; soil

Climate drives the biological processes occurring in soil yet is a poorly described and seldom considered part of nitrogen management in agriculture. This is due to the number and complexity of processes involved in the soil N cycle. In this proposal we examine the role of climatic triggers (thawing of frozen soil and wetting of dry soil) in stimulating bursts of microbial activity and causing soil N losses. Specifically this work focuses on the influence substrate availability on inorganic nitrogen processes that control the timing and relative importance of nitrification and denitrification in producing N2O emissions. My hypothesis is that environmental events trigger microbial metabolism through the release of substrates as a result of microbial cell-lysis and solubilization of soil organic matter. Further, it is the rate at which microbial metabolism acts on these substrates, as influenced by soil temperature and water content, and the architecture of carbon and nitrogen distribution which determines the location, intensity, and products of denitrification and therefore N2O emissions.

气候驱动着土壤中发生的生物过程，但描述的很少，很少被认为是农业中氮管理的一部分。这是由于土壤n周期中涉及的过程的数量和复杂性。在此提案中，我们研究了气候触发因素（冻结土壤和干燥土壤润湿）在刺激微生物活性爆发中的作用，并导致土壤N损失。具体而言，这项工作着重于底物对无机氮过程的影响，这些过程控制了硝化和硝化在产生N2O排放中的时机和相对重要性。我的假设是，环境事件通过微生物细胞溶解酶和土壤有机物的溶解而引发微生物代谢。此外，这是微生物代谢对这些底物作用的速率，受土壤温度和水含量的影响，以及碳和氮分布的结构决定了硝化剂的位置，强度和产物，从而决定了N2O的排放。