Earthworm-microbial interactions controlling nitrous oxide production in perennial grass- and legume- based agroecosystems using stable isotopes and molecular markers

使用稳定同位素和分子标记控制多年生草和豆类农业生态系统中一氧化二氮产生的蚯蚓-微生物相互作用

基本信息

批准号：
238323-2010
负责人：
Whalen, Joann
金额：
$ 3.13万
依托单位：
McGill University
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2013
资助国家：
加拿大
起止时间：
2013-01-01 至 2014-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=524285
关键词：
Earthworm microbial interactions controlling nitrous

项目摘要

Earthworms are well known for their contribution to soil fertility and crop production. Agroecosystems with perennial vegetation, such as grass- and legume-based hayfields, support large earthworm populations because soils are undisturbed by cultivation and senescing plant residues are a food source for earthworms. Under these conditions, earthworm-created structures like surface and subsurface casts (fecal pellets), middens (soil-litter mixture at the soil surface) and burrows are numerous. These structures are a favorable habitat for microbial nitrifiers and denitrifiers that produce nitrous oxide, a potent greenhouse gas, as a byproduct of their metabolism. Previous laboratory studies by my research group have shown that earthworms stimulate nitrous oxide production, leading me to hypothesize that earthworm-microbial interactions lead to nitrous oxide production at small scales (microcosms, small field plots) and may contribute to seasonal nitrous oxide emissions at the agroecosystem level. These biological interactions will be evaluated with cutting-edge research tools, including 15N isotope dilution and DNA methods (q-PCR amplification of amoA, nosZ and other relevant genes, DNA-stable isotope probing). These advanced techniques tremendously increase our chance of discovering novel organisms and gaining new insights into microbially-mediated N transformations. Mathematical functions describing the earthworm-microbial relationships that contribute to nitrous oxide emissions from soils will be incorporated into predictive ecosystem-level models (DNDC, ecosys), which may eventually be used to calculate national greenhouse gas inventories with the IPCC Phase III methodology. In the next five years, this project will train 12 highly qualified personnel with specialized knowledge and analytical skills that are highly desired for research positions in the environmental sciences.

earth因其对土壤生育能力和作物生产的贡献而闻名。具有多年生植被的农业生态系统，例如基于草和豆科植物的干草菲尔德，支持较大的earth种群，因为土壤不受培养和吞噬植物残留的影响是earth的食物来源。在这些条件下，earth创建的结构如表面和地下铸造（粪便颗粒），中间（土壤表面的土壤混合物）和毛刺很多。这些结构是微生物亚硝化剂和非生产剂的有利栖息地，它们产生一氧化二氮（一种有效的温室气），作为其代谢的副产品。我的研究小组的实验室研究以前的研究表明，earth刺激一氧化二氮的产生，使我假设earth虫 - 微生物相互作用会导致一硝酸氧化物在小尺度上（微观，小田间图）产生，并可能有助于季节性的氧化氮氧化物发射。农业生态系统级别。这些生物相互作用将通过最先进的研究工具进行评估，包括15N同位素稀释和DNA方法（Q-PCR扩增AMOA，NOSZ和其他相关基因，DNA稳定的同位素探测）。这些先进的技术极大地增加了我们发现新生物并获得微生物介导的N转化的新见解的机会。描述有助于土壤一氧化二氮的earth微生物关系的数学功能将纳入预测性生态系统级模型（DNDC，ecosys）中，最终可以用IPCC III阶段方法来计算国家温室气体库存。在接下来的五年中，该项目将培训12名具有专业知识和分析技能的高素质人员，这些人员非常需要环境科学的研究职位。