The integration of site-specific measures of soil N status and climate in improving nitrogen fertilizer use efficiency in cool humid climates

结合土壤氮状况和气候的特定地点措施来提高凉爽湿润气候下氮肥的利用效率

• 批准号: RGPIN-2020-07043
• 负责人: Burton, David
• 金额: $ 2.19万
• 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: 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=717653
• 关键词: integration; site; specific; measures; soil

One of humanity's greatest short comings has been a failure to detect and respect ecological limits. This is particularly true of land management and nutrient loading to the environment (11,17). Synthetic nitrogen (N) fertilizer adds 120 million tonnes of N to the environment annually and has effectively doubled the reactive N present on the Earth (16). Only about 50% of N fertilizer used in agriculture is taken up by the crop, while the rest remains in the environment (11). Inefficient N use is a result of numerous pathways of N loss from soil and the role of weather events in triggering N losses. To improve the efficiency of N use we must better account for all sources of N, including the soil, and ensure reactive N does not accumulate during periods of high N loss potential. Increasing N use efficiency is tied to six of the seventeen UN Sustainable Development Goals (1). The Atlantic region is the focus of this research as cropping systems there occur on low fertility soils, require high rates of N fertilizer addition and are in close proximity to vulnerable surface water and groundwater systems. This region is typical of cool, humid agroecosystems which have the highest rates of agricultural N impacts on surrounding ecosystems. This work examines the influence of climate on soil N functions, determines the role of climate in triggering N processes, and evaluates probabilistic estimates of soil N supply/loss as usable and useful information for agricultural producers and/or policy makers The role of dissolved organic N in controlling the availability of N to plants and potential for loss to the environment is poorly understood. We will discover the link between climate triggers (freeze/thaw, dry/wet) and the solubilization of organic N which we hypothesize is the rate limiting step in soil N supply to plants and loss to the environment. This will result in improved estimates of soil N supply. We will use site-specific measures of soil N function and climate to generate probability-based Bayesian predictors of soil N supply/loss. These Bayesian statistical approaches will build on past research and produce tools that will allow producers to integrate current climate information and probability-based, georeferenced estimates of soil N supply to develop site-specific, crop-specific N recommendations, improving N use efficiency and reduced environmental impact. The Bayesian predictors of soil N functions will be used in combination with future climate scenarios to examine the potential impacts of climate change on soil N supply and the potential for soil N loss to the environment. These projects will combine field and laboratory studies to translate science-based measures of soil N status into probabilistic, geo-referenced tools that can be used by agricultural producers and policy makers alike to improve the efficiency of N use in agriculture and the sustainability of agriculture in Canadian cool humid agro-ecosystems.

人类最大的缺点之一就是未能发现和尊重生态极限。这在土地管理和环境养分负荷方面尤其如此（11，17）。合成氮（N）肥料每年向环境增加1.2亿吨氮，有效地使地球上存在的活性氮翻了一番（16）。农业中使用的氮肥只有约50%被作物吸收，其余的仍留在环境中。氮素利用效率低下是土壤氮素流失的多种途径和天气事件触发氮素流失的作用的结果。为了提高氮素利用效率，我们必须更好地考虑包括土壤在内的所有氮素来源，并确保活性氮不会在氮素流失潜力高的时期积累。提高氮肥利用效率与17个联合国可持续发展目标中的6个目标有关。 大西洋地区是这项研究的重点，因为那里的种植系统发生在低肥力土壤上，需要高比例的氮肥添加，并靠近脆弱的地表水和地下水系统。该地区是典型的凉爽，潮湿的农业生态系统，农业氮对周围生态系统的影响率最高。本研究探讨了气候对土壤氮素功能的影响，确定了气候在触发氮素过程中的作用，并评估了土壤氮素供应/损失的概率估计，作为农业生产者和/或政策制定者有用的信息 溶解性有机氮在控制植物氮素有效性和潜在环境损失方面的作用知之甚少。我们将发现气候触发因素（冻/融，干/湿）和溶解的有机氮，我们假设是土壤氮供应到植物和环境损失的限速步骤之间的联系。这将导致改善土壤氮供应的估计。 我们将使用特定地点的土壤氮功能和气候的措施，以产生基于概率的贝叶斯土壤氮供应/损失预测。这些贝叶斯统计方法将建立在过去的研究和生产工具的基础上，使生产者能够整合当前的气候信息和基于概率的土壤氮供应地理参考估计，以制定特定地点，特定作物的氮建议，提高氮的利用效率并减少环境影响。 土壤氮功能的贝叶斯预测因子将与未来气候情景结合使用，以研究气候变化对土壤氮供应的潜在影响和土壤氮流失到环境中的可能性。 这些项目将结合联合收割机实地和实验室研究，将土壤氮素状况的科学措施转化为概率，地理参考工具，可供农业生产者和政策制定者使用，以提高农业氮素利用效率和加拿大凉爽潮湿农业生态系统的农业可持续性。