Assessing the impacts of cover crops on maize and soybean yield in the U.S. Midwestern agroecosystems
Assessing the impacts of cover crops on maize and soybean yield in the U.S. Midwestern agroecosystems
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DOI：
10.1016/j.fcr.2021.108264
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发表时间：
2021-11
影响因子：
5.8
通讯作者：
Ziqi Qin;K. Guan;Wang Zhou;B. Peng;M. Villamil;Zhenong Jin;Jinyun Tang;R. Grant;L. Gentry;A. Margenot;G. Bollero;Ziyi Li
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作者：
Ziqi Qin;K. Guan;Wang Zhou;B. Peng;M. Villamil;Zhenong Jin;Jinyun Tang;R. Grant;L. Gentry;A. Margenot;G. Bollero;Ziyi Li
种植覆盖作物是最有希望的保护做法之一，具有多种好处。然而，覆盖作物对玉米-大豆[Zea MaysL.--大豆(L.)[MERR.]根据田间试验的结果，美国中西部的轮作制度仍然存在很大的不确定性，特别是在不同的土壤特性、气候条件和土地管理实践中。基于过程的模型充分验证了这些不同条件下的田间试验数据，提供了一个有效的工具来量化覆盖作物对经济作物生产力的影响，并相应地优化覆盖作物的管理。在这项研究中，我们旨在回答以下问题：(1)覆盖作物对美国中西部农业生态系统经济作物产量的影响是什么？(2)覆盖作物影响经济作物产量的机制途径是什么(例如，通过影响土壤水、氮和氧气动态)？(3)可以采用什么管理措施来缓解覆盖作物对经济作物产量的负面影响？为了解决这些问题，我们利用2013年至2018年伊利诺伊州的田间试验数据，校准和验证了一个复杂的基于过程的农业生态系统模型-生态系统，然后使用生态系统评估了不同管理措施下冬季覆盖作物对玉米和大豆产量的影响。结果表明：(1)种植非豆科作物可使玉米减产3.9±3%，对大豆产量无显著影响，而种植豆科作物对玉米和大豆产量均无显著影响：(2)种植覆盖作物引起的玉米减产主要是由于固氮量增加、旱地水分竞争、地表凉爽和氧气竞争等引起的氮素缺乏所致；(3)在玉米之前终止非豆科作物可能会由于对资源(如水和氮)的激烈竞争而导致更大的玉米产量损失，通过优化春季覆盖作物的终止时间可以最大限度地减少非豆科作物对玉米减产的影响。总体而言，在美国中西部玉米-大豆轮作体系中，我们发现，尽管非豆类覆盖作物通过资源竞争导致玉米减产，但通过控制覆盖作物的终止时间和适当的肥料管理等管理措施，可以最大限度地减少这种减产。
Growing cover crops is one of the most promising conservation practices with multiple benefits. However, the impacts of cover crops on the productivity of the maize-soybean [Zea maysL. -Glycine max(L.) Merr.] rotation system in the U.S. Midwest still have large uncertainties based on results obtained from field experiments, specifically across different soil properties, climate conditions, and land management practices. Process-based models fully validated with data from field experiments across these diverse conditions provide an effective tool to quantify cover crop impacts on cash crop productivity and optimize the management of cover crops accordingly. In this study, we aim to answer the following questions: (1) What are the impacts of cover crops on cash crop yield in the U.S. Midwest agroecosystems? (2) What are the mechanistic pathways of cover crop to affect cash crop yield (e.g. through influencing soil water, nitrogen and O2dynamics)? (3) What management practices can be used to mitigate the negative impacts on cash crop yield caused by cover crops? To address these questions, we calibrated and validated a sophisticated process-based agroecosystem model,ecosys, using field experimental data from 2013 to 2018 across Illinois, and then usedecosysto assess the impacts of winter cover crops on maize and soybean yield under different management practices. Our study revealed the following findings: (1) planting non-legume cover crops can cause 3.9 ± 3% yield reduction for maize and no significant impacts on soybean yield, while planting legume cover crops has no significant impact on the yield of either maize or soybean; (2) the maize yield reduction caused by planting cover crops can be mainly explained by nitrogen deficiency induced by increased immobilization, water competition in dry areas, cooler soil surface and oxygen competition; (3) later termination of non-legume cover crops before maize can result in larger maize yield loss due to intensive competition for resources (e.g. water and nitrogen), and the impacts of non-legume cover crops on maize yield reduction can be minimized by optimizing cover crop termination time in the spring. Overall, in the U.S. Midwestern maize-soybean rotation system, we found that although non-legume cover crops cause yield reduction for maize through resource competition, this yield reduction can be minimized through management practices, such as controlling termination time of cover crop and proper fertilizer management.