Bidoglio Giorgio A, Mueller Nathaniel D, Kastner Thomas
Senckenberg Biodiversity and Climate Research Centre (SBIK-F), Frankfurt am Main, Germany.
Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, USA; Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA.
Sci Total Environ. 2023 May 15;873:162226. doi: 10.1016/j.scitotenv.2023.162226. Epub 2023 Feb 19.
In our globalized world, local impacts of agricultural production are increasingly driven by consumption in geographically distant places. Current agricultural systems strongly rely on nitrogen (N) fertilization to increase soil fertility and crop yields. Yet, a large portion of N added to cropland is lost through leaching / runoff potentially leading to eutrophication in coastal ecosystems. By coupling data on global production and N fertilization for 152 crops with a Life Cycle Assessment (LCA)-based model, we first estimated the extent of oxygen depletion occurring in 66 Large Marine Ecosystems (LMEs) due to agricultural production in the watersheds draining into these LMEs. We then linked this information to crop trade data to assess the displacement from consuming to producing countries, in terms of oxygen depletion impacts associated to our food systems. In this way, we characterized how impacts are distributed between traded and domestically sourced agricultural products. We found that few countries dominate global impacts and that cereal and oil crop production accounts for the bulk of oxygen depletion impacts. Globally, 15.9 % of total oxygen depletion impacts of crop production are ascribable to export-driven production. However, for exporting countries like Canada, Argentina or Malaysia this share is much higher, often up to three-quarters of their production impacts. In some importing countries, trade contributes to reduce pressure on already highly affected coastal ecosystems. This is the case for countries whose domestic crop production is associated with high oxygen depletion intensities, i.e. the impact per kcal produced, such as Japan or South Korea. Next to these positive effects trade can play in lowering overall environmental burdens, our results also highlight the importance of a holistic food system perspective when aiming to reduce the oxygen depletion impacts of crop production.
在我们这个全球化的世界中，农业生产对当地的影响越来越受到地理上遥远地区消费的驱动。当前的农业系统严重依赖氮肥来提高土壤肥力和作物产量。然而，施用于农田的大部分氮素通过淋溶/径流流失，这可能导致沿海生态系统富营养化。通过将152种作物的全球生产和氮肥施用数据与基于生命周期评估（LCA）的模型相结合，我们首先估算了流入66个大型海洋生态系统（LME）的流域内农业生产所导致的这些LME中氧气消耗的程度。然后，我们将这些信息与作物贸易数据相联系，以评估消费国与生产国之间在与我们的食物系统相关的氧气消耗影响方面的转移情况。通过这种方式，我们描述了影响在贸易农产品和国内来源农产品之间的分布情况。我们发现，少数国家主导着全球影响，谷物和油料作物生产占氧气消耗影响的大部分。在全球范围内，作物生产总氧气消耗影响的15.9%可归因于出口驱动型生产。然而，对于加拿大、阿根廷或马来西亚等出口国来说，这一比例要高得多，通常高达其生产影响的四分之三。在一些进口国，贸易有助于减轻对已经受到严重影响的沿海生态系统的压力。日本或韩国等国内作物生产与高氧气消耗强度（即每千卡生产所产生的影响）相关的国家就是这种情况。除了贸易在降低总体环境负担方面可以发挥的这些积极作用外，我们的研究结果还凸显了在旨在减少作物生产的氧气消耗影响时采用整体食物系统视角的重要性。
