Untangling irrigation effects on maize water and heat stress alleviation using satellite data
Untangling irrigation effects on maize water and heat stress alleviation using satellite data
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DOI：
10.5194/hess-26-827-2022
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发表时间：
2022-02
影响因子：
6.3
通讯作者：
P. Zhu;J. Burney
中科院分区：
文献类型：
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作者：
P. Zhu;J. Burney
抽象。灌溉对维持全球粮食生产具有重要意义，因为即使在干旱条件下也能满足作物对水的需求。增加的水也通过蒸腾作用冷却作物;因此，灌溉可能在温暖的气候中发挥重要作用，同时缓和水和高温胁迫。在这里，我们使用卫星获得的蒸散量估计，地表温度（LST）测量，以及作物物候期信息内布拉斯加州玉米，以量化灌溉如何缓解水和温度压力。与气温指标不同，卫星获得的LST揭示了显着的灌溉引起的冷却效果，特别是在作物生长的灌浆期（GFP）。这种冷却似乎延长了玉米生长季节，特别是对于GFP，可能是由于在此阶段期间物候发育的温度敏感性更强。分析还表明，灌溉不仅减轻了水分和温度胁迫，而且减弱了产量对这些胁迫的反应。具体而言，温度胁迫显着减弱灌溉玉米的生殖过程。归因分析进一步表明，水分和高温胁迫缓解分别占灌溉产量效益的65± 10%和35± 5.3%。我们的研究强调了高温胁迫缓解在产量提高中的相对重要性，以及模拟作物表面温度以更好地量化作物产量模型中热胁迫效应的必要性。最后，考虑到水和热胁迫之间潜在的强烈相互作用，未来关于灌溉效益的研究应探索热与缓解干旱之间的相互作用效应。
Abstract. Irrigation has important implications for sustaining global food production by enabling crop water demand to be met even under dry conditions. Added water also cools crop plants through transpiration; irrigation might thus play an important role in a warmer climate by simultaneously moderating water and high temperature stresses. Here we used satellite-derived evapotranspiration estimates, land surface temperature (LST) measurements, and crop phenological stage information from Nebraska maize to quantify how irrigation relieves both water and temperature stresses. Unlike air temperature metrics, satellite-derived LST revealed a significant irrigation-induced cooling effect, especially during the grain filling period (GFP) of crop growth. This cooling appeared to extend the maize growing season, especially for GFP, likely due to the stronger temperature sensitivity of phenological development during this stage. Our analysis also revealed that irrigation not only reduced water and temperature stress but also weakened the response of yield to these stresses. Specifically, temperature stress was significantly weakened for reproductive processes in irrigated maize. Attribution analysis further suggested that water and high temperature stress alleviation was responsible for 65±10 % and 35±5.3 % of the irrigation yield benefit, respectively. Our study underlines the relative importance of high temperature stress alleviation in yield improvement and the necessity of simulating crop surface temperature to better quantify heat stress effects in crop yield models. Finally, considering the potentially strong interaction between water and heat stress, future research on irrigation benefits should explore the interaction effects between heat and drought alleviation.