Department of Bioproducts and Biosystems Engineering, University of Minnesota Twin Cities, St. Paul, Minnesota, USA.
Department of Geography, The University of Hong Kong, Hong Kong, SAR, China.
Glob Chang Biol. 2024 Nov;30(11):e17556. doi: 10.1111/gcb.17556.
Crop rotation has been widely used to enhance crop yields and mitigate adverse climate impacts. The existing research predominantly focuses on the impacts of crop rotation under growing season (GS) climates, neglecting the influences of non-GS (NGS) climates on agroecosystems. This oversight limits our understanding of the comprehensive climatic impacts on crop rotation and, consequently, our ability to devise effective adaptation strategies in response to climate warming. In this study, we examine the impacts of both GS and NGS climate conditions on the yield effect of the preceding crop in corn-soybean rotation systems from 1999 to 2018 in the US Midwest. Using causal forest analysis, we estimate that crop rotation increases corn and soybean yields by 0.96 and 0.22 t/ha on average, respectively. We then employ statistical models to indicate that increasing temperatures and rainfall in the NGS reduce corn rotation benefits, while warming GS enhances rotation benefits for soybeans. By 2051-2070, we project that warming climates will reduce corn rotation benefits by 6.74% under Shared Socioeconomic Pathway (SSP) 1-2.6 and 17.18% under SSP 5-8.5. For soybeans, warming climates are expected to increase rotation benefits by 8.36% under SSP 1-2.6 and 13.83% under SSP 5-8.5. Despite these diverse climate impacts on both crops, increasing crop rotation could still improve county-average yields, as neither corn nor soybean was fully rotated. If we project that all continuous corn and continuous soybeans are rotated by 2051-2070, county-average corn yields will increase by 0.265 t/ha under SSP 1-2.6 and 0.164 t/ha under SSP 5-8.5, while county-average soybean yields will gain 0.064 t/ha under SSP 1-2.6 and 0.076 t/ha under SSP 5-8.5. These findings highlight the effectiveness of crop rotation in the face of warming NGS and GS in the future and can help evaluate opportunities for adaptation.
轮作已被广泛应用于提高作物产量和减轻不利气候影响。现有研究主要集中在生长季（GS）气候下轮作的影响，而忽略了非生长季（NGS）气候对农业生态系统的影响。这种忽视限制了我们对轮作对作物综合气候影响的理解，进而限制了我们针对气候变暖制定有效适应策略的能力。在这项研究中，我们从 1999 年到 2018 年，在美国中西部地区考察了 NGS 和 GS 气候条件对玉米-大豆轮作系统中前茬作物产量效应的影响。利用因果森林分析，我们估计轮作平均使玉米和大豆的产量分别增加了 0.96 和 0.22 吨/公顷。然后，我们使用统计模型表明，NGS 中温度和降雨量的增加会降低玉米轮作的效益，而 GS 的变暖则会增强大豆轮作的效益。到 2051-2070 年，我们预计在共享社会经济途径（SSP）1-2.6 和 SSP 5-8.5 下，变暖气候将使玉米轮作的效益分别减少 6.74%和 17.18%。对于大豆来说，预计在 SSP 1-2.6 和 SSP 5-8.5 下，变暖气候将使轮作效益分别增加 8.36%和 13.83%。尽管这两种作物的气候影响各不相同，但增加轮作仍可提高县平均产量，因为玉米和大豆都没有完全轮作。如果我们预测到 2051-2070 年所有连续种植的玉米和大豆都进行轮作，在 SSP 1-2.6 下，县平均玉米产量将增加 0.265 吨/公顷，在 SSP 5-8.5 下增加 0.164 吨/公顷，而在 SSP 1-2.6 下，县平均大豆产量将增加 0.064 吨/公顷，在 SSP 5-8.5 下增加 0.076 吨/公顷。这些发现强调了在未来变暖的 NGS 和 GS 环境下轮作的有效性，并有助于评估适应的机会。
