The United States is a world leader in the production of maize and other crops and the agricultural success of the country is directly linked to the intensive use of fertilizers and irrigation. However, even in advanced agricultural systems, soils can become degraded over time due to factors such as soil organic matter (SOM) loss and erosion. Here, we use a series of scenario‐based model analyses to show that about one‐third of current annual US. N fertilizer use in maize agriculture is used to compensate for the long‐term loss of soil fertility through erosion and organic matter loss. This leads to over a half billion dollars per year in extra fertilizer supply costs to US farmers. These results highlight the potential to reduce both the input costs and environmental impacts of agriculture through the restoration of SOM in agricultural soils.

中文翻译：

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美国玉米农业土地退化的隐性成本

美国在玉米和其他农作物的生产方面处于世界领先地位，该国的农业成功与化肥和灌溉的密集使用直接相关。但是，即使在先进的农业系统中，土壤也会由于诸如土壤有机质（SOM）损失和侵蚀等因素而随时间退化。在这里，我们使用一系列基于情景的模型分析来显示当前美国年度人口的约三分之一。玉米农业中使用的氮肥用于补偿由于侵蚀和有机物质流失而造成的长期土壤肥力损失。这导致每年向美国农民增加的肥料供应成本超过五亿美元。这些结果凸显了通过在农业土壤中恢复SOM减少农业投入成本和环境影响的潜力。