Several studies have explored the potential of electrical resistivity tomography to monitor changes in soil moisture associated with the root water uptake of different crops. Such studies usually use a set of limited below-ground measurements throughout the growth season but are often unable to get a complete picture of the dynamics of the processes. With the development of high-throughput phenotyping platforms, we now have the capability to collect more frequent above-ground measurements, such as canopy cover, enabling the comparison with below-ground data. In this study hourly DC resistivity data were collected under the Field Scanalyzer platform at Rothamsted Research with different winter wheat varieties and nitrogen treatments in 2018 and 2019. Results from both years demonstrate the importance of applying the temperature correction to interpret hourly electrical conductivity (EC) data. Crops which received larger amounts of nitrogen showed larger canopy cover and more rapid changes in EC, especially during large rainfall events. The varieties showed contrasted heights although this does not appear to have influenced EC dynamics. The daily cyclic component of the EC signal was extracted by decomposing the time series. A shift in this daily component was observed during the growth season. For crops with appreciable difference in canopy cover, high frequency DC resistivity monitoring was able to distinguish the different below-ground behaviors. The results also highlight how coarse temporal sampling may affect interpretation of resistivity data from crop monitoring studies.

中文翻译：

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冬小麦下的时间密集型地电监测

几项研究探索了电阻率层析成像技术在监测与不同作物根部吸水相关的土壤水分变化方面的潜力。此类研究通常在整个生长季节使用一组有限的地下测量值，但通常无法全面了解过程的动态。随着高通量表型平台的发展，我们现在有能力收集更频繁的地上测量数据，例如冠层覆盖，从而能够与地下数据进行比较。在这项研究中，在 Rothamsted Research 的 Field Scanalyzer 平台下收集了 2018 年和 2019 年不同冬小麦品种和氮处理的每小时直流电阻率数据。这两年的结果证明了应用温度校正来解释每小时电导率 (EC) 数据的重要性。接受大量氮的作物表现出更大的冠层覆盖和更快速的 EC 变化，尤其是在大降雨事件期间。品种表现出对比高度，尽管这似乎没有影响 EC 动态。通过分解时间序列提取EC信号的每日循环分量。在生长季节观察到这一日常成分的变化。对于冠层覆盖有明显差异的作物，高频直流电阻率监测能够区分不同的地下行为。结果还强调了粗略的时间采样可能如何影响对作物监测研究电阻率数据的解释。