Crop-climate feedbacks boost US maize and soy yields
Crop-climate feedbacks boost US maize and soy yields
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DOI：
10.1088/1748-9326/ac4aa0
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发表时间：
2022-02-01
影响因子：
6.7
通讯作者：
Mankin, Justin S.
中科院分区：
文献类型：
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作者：
Coffel, Ethan D.;Lesk, Corey;Mankin, Justin S.
自20世纪中期以来，美国玉米和大豆产量迅速增长。虽然全球变暖在这段时间内使大多数地区的气温升高，但美国农田的极端高温趋势较小，减少了对作物有害的高温，并有利于玉米和大豆的产量。在这里，我们表明农业集约化创造了作物-气候反馈，其中作物产量的增加使当地气候变冷，进一步提高了作物产量。我们发现，玉米和大豆生产趋势对美国中部极端高温地区的降温影响与温室气体引起的变暖趋势大致相同，并大大降低了美国南部地区的降温效应，使所有地区的作物受益。1981年至2019年期间，变暖减缓使玉米和大豆产量分别提高了3.3（2.7-3.9;13.7%-20.0%）和0.6（0.4-0.7;7.5%-13.7%）吨/年。我们的研究结果表明，如果玉米和大豆产量增长停滞，作物-气候反馈掩盖变暖的能力将会减弱，使美国作物面临更有害的极端高温。
US maize and soy production have increased rapidly since the mid-20th century. While global warming has raised temperatures in most regions over this time period, trends in extreme heat have been smaller over US croplands, reducing crop-damaging high temperatures and benefiting maize and soy yields. Here we show that agricultural intensification has created a crop-climate feedback in which increased crop production cools local climate, further raising crop yields. We find that maize and soy production trends have driven cooling effects approximately as large as greenhouse gas induced warming trends in extreme heat over the central US and substantially reduced them over the southern US, benefiting crops in all regions. This reduced warming has boosted maize and soy yields by 3.3 (2.7-3.9; 13.7%-20.0%) and 0.6 (0.4-0.7; 7.5%-13.7%) bu/ac/decade, respectively, between 1981 and 2019. Our results suggest that if maize and soy production growth were to stagnate, the ability of the crop-climate feedback to mask warming would fade, exposing US crops to more harmful heat extremes.