Improved understanding of soil organic matter stabilization in agricultural systems with contrasting input strategies.

通过对比投入策略，提高了对农业系统中土壤有机质稳定性的了解。

• 批准号: RGPIN-2020-04288
• 负责人: Gillespie, Adam
• 金额: $ 1.82万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=761836
• 关键词: Improved; understanding; soil; organic; matter

The long-term objectives of my research program are to understand how soil organic matter (SOM) composition and distribution in the landscape can be managed to promote sustainable agro-ecosystems. Soil organic matter buildup is recommended to develop healthy soils. It is also frequently suggested that healthy soils are better able to resist environmental stresses. This is becoming increasingly important as climate models are predicting more frequent and severe weather events, along with a general warming trend for the most agriculturally productive regions in Canada. The stability of soil organic matter (SOM) as it relates to resistance to microbial degradation has important implications for nutrient cycling, emission of greenhouse gases, erosion control and C sequestration. Most studies discuss the contributions of total SOM toward healthy and resilient soils; however, we know that SOM is heterogeneous. SOM composition is influenced by the types and amounts of plant and animal residues (or inputs) that the soil receives. Since the molecular structure of SOM influences its persistence in the environment, it is critical to understand how these inputs influence SOM composition because it has important implications for nutrient cycling, emission of greenhouse gases, erosion control and C sequestration. My research expertise combines a strong understanding of soil systems and state-of-the-art instrumentation used to understand ecosystem influences over the biogeochemistry of SOM. In this proposal, I use these advanced methods explore how different agricultural input strategies contribute to the overall composition of SOM. The overall goal is to identify SOM management strategies that would contribute to agroecosystem sustainability and resilience. The specific objectives of this proposal are: 1) Establish link between carbon inputs from crops and manure on the biological stability of SOM; 2) Elucidate the relationship between thermal stability of SOM and microbial substrate use efficiency; 3) Identify key organic matter composition differences from soils under contrasting organic input types and amounts using advanced spectroscopy; 4) design a process model which includes microbial, ecosystem and chemical controls over SOM cycling in agroecosystems. Findings from this work will have a significant impact on our fundamental understanding of how soil organic matter from inputs contributes to the mechanistic nature of SOM stability. Because soils selected for characterization in this study will come from a range of land management practices, we will be able to make robust, science-based recommendations for sustainable agricultural practices. Ultimately, this will lead to a better understanding of how agroecosystems can sequester carbon and be future-proofed against increased uncertainty and variability in climate and weather events.

我的研究计划的长期目的是了解如何设法促进景观中的土壤有机物（SOM）组成和分布来促进可持续的农业生态系统。建议建立土壤有机物来发展健康的土壤。还经常提出健康的土壤能够更好地抵抗环境应力。随着气候模型预测更频繁和恶劣的天气事件，加拿大最农业生产力最高的趋势的一般变暖趋势，这变得越来越重要。与微生物降解有关的土壤有机物（SOM）的稳定性对营养循环，温室气体的排放，侵蚀控制和C隔离具有重要意义。大多数研究都讨论了SOM对健康和韧性土壤的贡献。但是，我们知道SOM是异质的。 SOM组成受土壤收到的动植物残留物（或输入）的类型和量的影响。由于SOM的分子结构会影响其在环境中的持久性，因此了解这些输入如何影响SOM组成是至关重要的，因为它对养分循环，温室气体的排放，侵蚀控制和C隔离具有重要意义。我的研究专业知识结合了对土壤系统和最先进的仪器的深入了解，用于了解生态系统对SOM生物地球化学的影响。在此提案中，我使用这些高级方法探讨了不同的农业投入策略如何促进SOM的整体组成。总体目标是确定将有助于农业生态系统的可持续性和韧性的SOM管理策略。该提案的具体目标是：1）建立农作物的碳输入与肥料的碳输入之间的联系； 2）阐明SOM的热稳定性与微生物底物使用效率之间的关系； 3）使用先进的光谱法确定在对比的有机输入类型和数量下与土壤的关键有机物组成差异； 4）设计一个过程模型，其中包括对农业生态系统中SOM循环的微生物，生态系统和化学控制。这项工作的发现将对我们对投入的土壤有机物的基本理解产生重大影响，从而有助于SOM稳定性的机械性质。由于在这项研究中选择用于表征的土壤将来自一系列土地管理实践，因此我们将能够为可持续的农业实践提出强大的基于科学的建议。最终，这将使人们更好地了解农业生态系统如何隔离碳，并对不确定性和气候事件的不确定性和可变性提高。