Biotic controls on the residence time of soil carbon and nitrogen: new understanding from stable isotope probing and optimization modeling

对土壤碳和氮停留时间的生物控制：稳定同位素探测和优化模型的新认识

• 批准号: RGPIN-2017-05391
• 负责人: Whalen, Joann
• 金额: $ 4.23万
• 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: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=711345
• 关键词: Biotic; controls; residence; time; soil

Increasing globalization of the agricultural sector and growth of the bioenergy sector creates incentives for Canadian farmers to produce more food, fiber and feedstock. This must be done sustainably, so agricultural products meet the high quality standards of processors and the general public, economic profits and jobs remain in our rural communities and farming activities are aligned with agro-environmental objectives. Sustainable agroecosystems are envisioned to conserve soil organic carbon (C) and rely more on internal soil nitrogen (N) recycling, thus contributing to C sequestration and avoiding inefficient N fertilizer use. Nutrient conservation is especially important in humid temperate regions of Canada because soils are more vulnerable to nutrient loss in areas with high precipitation regimes and 50% of Canadian farms are located in these regions. The living soil' concept is a possible solution since it relies upon the naturally-occurring soil microorganisms and fauna to simultaneous decompose and synthesize organic C and N, but since these processes occur rapidly, at a microscopic level, within soil pores, we do not know how the soil foodweb contributes to crop production at an farm operations level. Here, we will tackle the problem at three different scales: (i) from the pore-scale with stable isotope probing methods and high-resolution image analysis, (ii) considering energetics and trophic transfers that occur within the soil foodweb, and (iii) at the field scale, using an optimization modelling to determine the temporal transformations of organic and inorganic fertilizer inputs through the soil biotic community, in relation to crop nutrient demands. The novelty of this research program is its contribution to fundamental research questions regarding the biological processes that control C and N cycling in agroecosystems, which is integrated into an applied decision-making model that provides practical answers for the Canadian farming community. The principal investigator contributed to the training of many HQP in the past 6 years, including 10 M.Sc. and 16 Ph.D. graduates, More than 90 peer-reviewed papers were published in international journals during this period, most of which had HQP as first author. This proposal will support 12 trainees through an individualized training program that includes peer-to-peer mentoring and focuses on excellent scientific communication, networking and professional skills acquisition. This provides outstanding preparation for their future role as scientific leaders, as evidenced by the demand for these trainees in academic, government and industry jobs that require advanced technical skills and managerial abilities.

增加农业部门的全球化和生物能源部门的增长为加拿大农民生产更多食物，纤维和原料提供了激励措施。必须可持续地做到这一点，因此农产品符合高质量的加工者，公众，经济利润和工作仍然存在于我们的农村社区，农业活动与农业环境目标保持一致。设想可持续的农业生态系统可以保存土壤有机碳（C），并更多地依赖内部土壤氮（N）回收，从而有助于C隔离并避免使用效率低下的N肥料使用。在加拿大的潮湿温带地区，养分尤其重要，因为土壤在降水状态高的地区更容易受到养分损失的影响，而加拿大农场的50％位于这些地区。生命的土壤概念是一种可能的解决方案，因为它依赖于自然存在的土壤微生物和动物区系同时分解和合成有机C和N，但是由于这些过程在微观孔中迅速发生，因此在土壤孔中，我们不知道土壤食品在农业水平上如何贡献农产品的作物。 Here, we will tackle the problem at three different scales: (i) from the pore-scale with stable isotope probing methods and high-resolution image analysis, (ii) considering energetics and trophic transfers that occur within the soil foodweb, and (iii) at the field scale, using an optimization modelling to determine the temporal transformations of organic and inorganic fertilizer inputs through the soil biotic community, in relation to crop nutrient需求。该研究计划的新颖性在于它对控制农业生态系统中C和N循环的生物学过程的基础研究问题的贡献，该过程被整合到一个应用决策模型中，该模型为加拿大农业社区提供了实际答案。在过去的6年中，主要研究人员为许多HQP培训做出了贡献，包括10 M.Sc。和16博士学位在此期间，在国际期刊上发表了毕业生，有90多篇经同行评审的论文发表，其中大多数是HQP作为第一作者。该提案将通过一个个性化的培训计划来支持12名受训者，其中包括点对点指导，并专注于出色的科学沟通，网络和专业技能获取。这为他们作为科学领导者的未来作用提供了出色的准备，这是对这些学术，政府和行业工作中需要高级技术技能和管理能力的受训者的需求所证明的。