Laboratory Evaluation of a Commercial Dielectric Soil Water Sensor
Laboratory Evaluation of a Commercial Dielectric Soil Water Sensor
复制标题
商用介电土壤水传感器的实验室评估
DOI：
10.2136/vzj2003.6500
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发表时间：
2003
影响因子：
2.8
通讯作者：
R. Lascano
中科院分区：
文献类型：
--
作者：
B. Mcmichael;R. Lascano
制定有效利用作物生产用水的管理战略需要动态测量土壤水分含量的变化。目前用于测量这些变化的许多方法对于大规模调查来说都是破坏性的、缓慢的或相对昂贵的。在实验室条件下，对两个土壤系列(Amarillo细砂壤土[细壤土、混合土、超活性热性阿里迪克棕壤土]和Pullman粘土[细土、混合土、热土Paleustolls])和一种覆盖广泛水分范围的耕作材料进行了评估，结果表明，一种商用、低成本、无损的土壤水分传感器可以根据土壤水介电常数的变化来测量土壤体积含水率(VWC)的变化。探头被放置在装满去离子水和土壤的容器中。装有Amarillo细砂壤土的容器被放置在可编程的温度室中，并受到温度和VWC的一系列变化。装有Pullman土壤和盆栽材料的容器只在恒温下受到VWC的变化。在风干和VWC值为0.25m3m−3之间的恒温下，普尔曼土壤和盆栽材料的探头输出是线性的，而阿马里洛土壤是非线性的。当Amarillo土壤温度在15.9~39.1°C−1之间变化时，在恒定的VWC值下，探头输出当量为0.10m3m−3。风干土壤的温度灵敏度为0.5 mV°C−1，湿Amarillo土壤为5 mV°C−1。我们的结论是，探头的输出是特定于土壤的，并且考虑到某些土壤对水分增加的非线性响应和对温度的敏感性，将需要特定于土壤的校准方程。
Development of management strategies for efficient water utilization of crop production requires measurements of changes in soil water content on a dynamic basis. Many of the methods currently used for measuring these changes are destructive, slow, or relatively expensive for large‐scale investigations. A commercially available, low‐cost, nondestructive soil moisture sensor for measuring changes in soil volumetric water content (VWC) on the basis of changes in the dielectric constant of the soil water was evaluated under laboratory conditions for two soil series (Amarillo fine sandy loam [fine‐loamy, mixed, superactive, thermic Aridic Paleustalfs] and Pullman clay loam [fine, mixed, thermic Torretic Paleustolls]) and a potting material across a wide range of water contents. Probes were placed in containers filled with deionized water and soil. Containers with Amarillo fine sandy loam were placed in a programmable temperature chamber and subjected to a series of changes in both temperature and VWC. Containers with Pullman soil and potting material were only subjected to changes in VWC at a constant temperature. Probe output at a constant temperature between air dry and a VWC of 0.25 m3 m−3 was linear for the Pullman soil and potting material and nonlinear for the Amarillo soil. When the Amarillo soil temperature varied between 15.9 and 39.1°C−1 at a constant VWC, probe output changed the equivalent of 0.10 m3 m−3 The temperature sensitivity was 0.5 mV °C−1 for air‐dry and about 5 mV °C−1 for wet Amarillo soil. We conclude that probe output is soil specific and, given the nonlinear response to increasing water content on some soils and sensitivity to temperature, will require soil‐specific calibration equations.