Long-term crop rotation diversification enhances maize drought resistance through soil organic matter
Long-term crop rotation diversification enhances maize drought resistance through soil organic matter
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DOI：
10.1088/1748-9326/ac1468
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发表时间：
2021-08
影响因子：
6.7
通讯作者：
Leah L R Renwick;W. Deen;L. Silva;M. Gilbert;T. Maxwell;Timothy M. Bowles;A. Gaudin
中科院分区：
文献类型：
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作者：
Leah L R Renwick;W. Deen;L. Silva;M. Gilbert;T. Maxwell;Timothy M. Bowles;A. Gaudin
适应气候变化需要建立农业系统对更温暖、更干燥气候的适应能力。通过作物轮作多样化增加时间植物多样性增加了一些干旱作物的产量，但其增强作物抗旱性的潜力和潜在机制尚不清楚。我们在温带气候下进行了一项为期36年的作物轮作、多样性和免耕试验，并在田间和实验室测量了一系列土壤和作物的发育和生态生理特性，进行了干旱操纵试验。结果表明，玉米-大豆轮作采用小粒谷物和覆盖作物，可缓解玉米叶片和冠层水分胁迫，减少干旱损失17.1±6.1%，而免耕不影响玉米的抗旱性。通径分析表明，尽管土壤有机质在轮作和耕作处理之间没有显着差异，但土壤有机质与较低的玉米水分胁迫之间存在很强的相关性。土壤有机质与玉米水分状况之间的这种正相关关系并不是由通常假设的较高的土壤保水或入渗所介导的，也不是由稳定同位素测量的根系吸水深度的差异所介导的，这表明其他机制在起作用。作物轮作多样化是通过管理土壤有机质使作物生产适应气候变化的一种未得到重视的干旱管理工具。
Climate change adaptation requires building agricultural system resilience to warmer, drier climates. Increasing temporal plant diversity through crop rotation diversification increases yields of some crops under drought, but its potential to enhance crop drought resistance and the underlying mechanisms remain unclear. We conducted a drought manipulation experiment using rainout shelters embedded within a 36-year crop rotation diversity and no-till experiment in a temperate climate and measured a suite of soil and crop developmental and eco-physiological traits in the field and laboratory. We show that diversifying maize-soybean rotations with small grain cereals and cover crops mitigated maize water stress at the leaf and canopy scales and reduced yield losses to drought by 17.1 ± 6.1%, while no-till did not affect maize drought resistance. Path analysis showed a strong correlation between soil organic matter and lower maize water stress despite no significant differences in soil organic matter between rotations or tillage treatments. This positive relationship between soil organic matter and maize water status was not mediated by higher soil water retention or infiltration as often hypothesized, nor differential depth of root water uptake as measured with stable isotopes, suggesting that other mechanisms are at play. Crop rotation diversification is an underappreciated drought management tool to adapt crop production to climate change through managing for soil organic matter.