Soil water content (SWC, % vol) is a key factor affecting plant growth and development. SWC measurement is vital to rational use of water resources for irrigation, and the accuracy of sensors in SWC measurement is of significant importance to smart data-driven irrigation. Here, a laboratory experiment and a field lysimetric experiment were conducted to evaluate the accuracy of Insentek sensors under various soil conditions (1.1 to 1.5 bulk densities and sand to clay soil textures) and irrigation levels (30, 45, and 60 mm), in 2018 and 2019. A microweighing lysimeter and oven-drying method were used as standard methods to compare the Insentek method. The root mean square error (RMSE, % vol) and relative prediction deviation (RPD) between the Insentek and microlysimetric SWC values were 0.89–1.04% vol and 5.6–6.8, respectively, under laboratory condition. The RPD value is larger than the threshold value of 4.0, indicating the accuracy of the Insentek sensors is reliable under laboratory condition. Except for 60 mm irrigation treatment, the RMSE between Insentek and the oven-drying method under field condition was 1.44–1.93% vol, and the RPD value was 1.56–1.93, lower than the threshold value of 4.0. The tiny gap between the Insentek sensor and soil may accelerate water infiltration along the probe 0-3 d after irrigation while increase air filling 5–7 d after irrigation, causing greater RMSE and lower RPD values. The dissatisfied performance in field condition may also be associated with the obvious drawbacks of oven-drying method, such as disturbance in soil sampling. When using oven-drying method to analyze the accuracy of the Insentek sensors in field condition, the concerns should be well addressed.

中文翻译：

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实验室和野外条件下FDR传感器在土壤水分测量中的精度分析

土壤含水量（SWC，％vol）是影响植物生长发育的关键因素。SWC测量对于合理利用水资源进行灌溉至关重要，SWC测量中传感器的准确性对于智能数据驱动的灌溉至关重要。在这里，进行了实验室实验和现场溶度测定实验，以评估Insentek传感器在各种土壤条件下（1.1至1.5的堆密度和沙子到黏土的土壤质地）和灌溉水平（30、45和60 mm）的精度。 2018年和2019年。使用微秤测力计和烤箱干燥法作为标准方法来比较Insentek方法。Insentek和微溶SWC值之间的均方根误差（RMSE，％体积）和相对预测偏差（RPD）分别为0.89–1.04％vol和5.6–6.8。在实验室条件下。RPD值大于阈值4.0，表明Insentek传感器的精度在实验室条件下是可靠的。除60 mm灌溉处理外，Insentek与现场干燥方法之间的均方根误差（RMSE）为1.44–1.93％vol，RPD值为1.56–1.93，低于4.0的阈值。Insentek传感器与土壤之间的微小间隙可能会在灌溉后0-3 d加速水沿探头的渗透，而在灌溉后5-7 d增加空气填充，从而导致更大的RMSE和更低的RPD值。田间条件下不满意的性能还可能与烤箱干燥方法的明显缺点有关，例如土壤采样中的干扰。当使用烘箱干燥法分析Insentek传感器在野外条件下的精度时，