Abstract To mitigate adverse effects of climate change on agricultural productivity, it is essential to obtain a better understanding of how plant traits influence crop yields and profits. To explore such interactions, we used a coupled ecohydrological and biogeochemical model, ecosys, and applied it to an agricultural farm cultivating wheat in Ardmore, Oklahoma, USA. Our results show that positive impacts of elevated CO2 on winter wheat cannot offset negative influences of warming that shortens grain filling periods and thereby grain content. We found that CO2 fertilization effects were weaker than expected without additional fertilizer addition. To identify conditions that simultaneously optimize wheat yields and profits, we performed model optimization analyses by varying root radius, nutrient transfer conductance, and fertilizer application rates. Optimum conditions were found for root radius in the range 0.1–0.25 mm and nutrient transfer conductance in the range 0.004–0.008 h−1. However, under climate change, an additional 5.6 gN m−2 of fertilizer was required to maximize net profits compared to present-day climate conditions. These optimum conditions led to yield improvements of 38%, 23%, 20%, and 17% under RCP2.6, 4.5, 6.0, and 8.5, respectively, which in turn improved net profits by 98%, 90%, 76%, and 31% compared to baseline, respectively. That is, crop breeding alone may not be sufficient to meet growing food demands without additional N fertilizer applications. However, these higher fertilization application rates lead to increased nitrogen losses as leachate and N2O, motivating analyses on the net radiative balance of these systems and their sensitivity to future climate.

中文翻译：

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在气候变化下提高小麦产量和利润需要更多的肥料和贫瘠的根

摘要 为了减轻气候变化对农业生产力的不利影响，必须更好地了解植物性状如何影响作物产量和利润。为了探索这种相互作用，我们使用了生态水文和生物地球化学耦合模型ecosys，并将其应用于美国俄克拉荷马州阿德莫尔的一个种植小麦的农场。我们的研究结果表明，CO2 升高对冬小麦的积极影响不能抵消变暖的负面影响，这会缩短灌浆期，从而缩短谷物含量。我们发现在不添加额外肥料的情况下，二氧化碳施肥效果比预期的要弱。为了确定同时优化小麦产量和利润的条件，我们通过改变根半径、养分转移传导、和肥料施用率。根半径在 0.1-0.25 毫米范围内和养分转移电导在 0.004-0.008 h-1 范围内找到了最佳条件。然而，在气候变化下，与当前的气候条件相比，需要额外的 5.6 gN m-2 肥料才能最大限度地提高净利润。这些最佳条件使RCP2.6、4.5、6.0和8.5下的产量分别提高了38%、23%、20%和17%，进而将净利润提高了98%、90%、76%，和 31% 分别与基线相比。也就是说，在没有额外施氮肥的情况下，仅靠作物育种可能不足以满足不断增长的粮食需求。然而，这些较高的施肥率导致渗滤液和 N2O 等氮损失增加，