三种土壤水势传感器在原状与扰动黏壤土上测定精度评价

Measuring Accuracy Evaluation of Three Kinds of Water Potential Sensors for Undisturbed and Disturbed Clay Loam

分别在田间原状黏壤土和室内扰动黏壤土上安装MPS-1、MPS-6、pF水势传感器与TDR315L土壤水分传感器测定土壤水分特征曲线,通过比较测定结果的准确性,提出了三种土壤水势传感器的使用建议。结果表明:MPS-1传感器虽测量范围窄,但无论在原状黏壤土还是扰动黏壤土上均表现良好;MPS-6和pF传感器测量范围宽,但测量的水势值精度不高,且MPS-6传感器对温度敏感,pF传感器在使用期间内表现不稳定。MPS-1传感器应用于原状和扰动黏壤土由其数据拟合出的土壤水分特征曲线与对照曲线重合度较高,而MPS-6和pF传感器应用于原状和扰动黏壤土,当含水量高于0.30 cm^3cm^-3时测定结果拟合得到的水分特征曲线与对照曲线重合度较高。比较三个水势传感器的测量表现,可以认为MPS-1传感器用于含水量高于0.30 cm3cm-3的原状黏壤土和含水量高于0.17 cm^3cm^-3的扰动黏壤土,MPS-6传感器用于含水量高于0.30 cm^3cm^-3的原状和扰动黏壤土测定土壤水势的效果较好。本研究结果可为使用上述三种传感器测定土壤水分特征曲线提供参考。

The accuracy of three soil water potential sensors were investigated for undisturbed and disturbed clay loam soil,in order to provide reference for soil water potential measurement and in-situ soil water characteristic curve measurement.MPS-1,MPS-6 and pF water potential sensors and TDR315 L soil moisture sensor were installed in the undisturbed and disturbed clay loam soil respectively.The soil water characteristic curves were fitted by the laboratory data and the sensor data,and then the accuracies of the three water potential sensors were compared.The results showed that MPS-1 sensor had a narrow measurement range,but performed accurately in its range of measurement when it was used in the disturbed and undisturbed clay loam soils.The MPS-6 and pF sensors had a wide measurement range but a low accuracy.The MPS-6 sensors were temperature sensitive and pF sensors were unstable during the measurement.The soil water characteristic curve fitted by MPS-1 sensors in the undisturbed and disturbed clay loam soils had a higher coincidence with the control curve.The curves fitted by MPS-6 and pF sensors for disturbed and undisturbed soils had good coincidences with the control curve at water content higher than 0.30 cm3 cm-3.Comparing the three water potential sensors,MPS-1 sensors are suitable to measure soil water potential in undisturbed clay loam soil with water content higher than 0.30 cm^3 cm^-3 and in disturbed clay loam soil with water content higher than 0.17 cm^3 cm^-3,MPS-6 sensors are suitable to measure soil water potential in undisturbed clay loam soil and in disturbed clay loam soil with water content higher than 0.30 cm^3 cm^-3.