Investigating soil carbon and nitrogen dynamics using stable isotopes in complex agroecosystems

使用复杂农业生态系统中的稳定同位素研究土壤碳和氮动态

• 批准号: 327456-2006
• 负责人: Oelbermann, Maren
• 金额: $ 2.05万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=366354
• 关键词: Investigating; soil; carbon; nitrogen; dynamics

Under global climate change scenarios, one of the challenges is to maintain agricultural productivity in order to meet current and projected trends in food production.  This challenge, coupled with large-scale soil and water degradation, will challenge the long-term and sustainable production of agricultural resources.  For example, a change in the amount, and in the chemical composition of organic residues applied to the soil, influences microbial processes and the stabilization of carbon (C), affecting the emission of greenhouse gases (GHG) such as carbon dioxide (CO2).  Therefore, the level of organic C in soil is a balance between the rate of C addition from crop residues and C losses as CO2 from microbial decay of these residues.  It is essential to evaluate GHG emissions from various agroecosystem management practices, and implement land-use systems that increase the amount of carbon (C) stored in the soil.  However, this potential has not yet been well quantified, and the mechanisms of interaction that regulate soil C and nitrogen (N) dynamics in complex agroeocsystems, like intercropping systems, are poorly understood.  This study provides information on how agroecosystem management practices affect GHG emissions, and the long-term assimilation and stabilization of C in the soil in complex agroecosystems.  The methodological approach will involve rigorous soil sampling, and build a comprehensive data set for the calibration of models.  Investigating GHG, soil C and N dynamics concurrently with soil biophysical characteristics enhances our understanding of total agroecosystem management. Information gained from this study provides further insight on agroecosystem design, the multiple benefits that systematically meet food production, and environmental goals to help mitigate GHG fluxes through the assimilation and stabilization of C in the soil.  This information will be of value for a variety of stakeholders and also foster international collaborative efforts.

在全球气候变化情景下，挑战之一是保持农业生产力，以满足当前和预测的粮食生产趋势，这一挑战，加上大规模的土壤和水退化，将对农业资源的长期和可持续生产提出挑战。例如，土壤中有机残留物的数量和化学成分的变化，影响微生物过程和碳（C）的稳定，影响温室气体（GHG）如二氧化碳（CO2）的排放。因此，土壤中有机碳的水平是作物残体的碳添加率与微生物分解残体产生的CO2损失率之间的平衡，因此评价不同农业生态系统的温室气体排放是必要的然而，这种潜力还没有得到很好的量化，在复杂的农业生态系统中，如间作系统，调节土壤碳和氮动态的相互作用机制也知之甚少。本研究提供了农业生态系统管理实践如何影响温室气体排放的信息，研究方法包括严格的土壤采样，建立一个全面的数据集用于模型的校准。温室气体、土壤C和N动态以及土壤生物物理特性的研究将增强我们对整个农业生态系统管理的理解。从这项研究中获得的信息提供了农业生态系统设计的进一步见解，系统地满足粮食生产的多重效益，以及通过土壤中C的同化和稳定来帮助减轻GHG通量的环境目标。