Soil moisture/Electric Conductivity - FDR (WET Sensor)
Parameter to be measured:
- Soil moisture, permittivity
- Indirect measurement of electric conductivity of pore water
- Temperature
Method:
Frequency Domain Sensor
Equipment:
- Delta-T Device: WET Sensor with 3 rods of 600 mm length, HH2 display for manual reading or a data logger
Advantages:
- easy and fast measurement of punctual soil moisture and electric conductivity of soil pore water
- manual as well as continuously logged measurements possible
Disadvantages:
- Each sensor has to be calibrated
- careful application of probe in stony soils
- Underestimating of permitivity in media with low permitivity (ε > 40, clay and organic soils)
- unaccurate values in saturated media
What to watch out for:
- Good contact between probe and medium has to be proved
Problems/Questions:
Links
Other related web sites:
References
- Balendonck, J., Bruins, M.A., Wattimena, M.R., Voogt, W., Huys, A. (2005): WET-sensor pore water EC calibration for three horticultural soils, Acta Horticulturae 691, ISSN 0567-7572, 789 - 796.
- Bouskila, F.,Persson, M., Berndtsson, R., Bahri, A. (2008), Soil water content and salinity determination using different dielectric methods in saline gypsiferous soil, HYDROLOG SCI J 53(1), 253-265.
- Hamed, Y.,Samy, G., Persson, M. (2006), Evaluation of the WET sensor compared to time domain reflectometry, HYDROLOG SCI J 51(4),671-681.
- Inoue, M., Ahmed, B.A., Saito, T., Irshad, M., Uzoma, K.C. (2008): Comparison of three dielectric moisture sensors for measurement of water in saline sandy soil, Soil Use and Management 24, 156–162, DOI: 10.1111/j.1475-2743.2008.00154.x.
- Kargas, G., Kerkides, P*, Seyfried, M, Sgoumbopoulou, A (2011): WET Sensor Performance in Organic and Inorganic Media with Heterogeneous Moisture Distribution, Soil Science Society of America Journal 75(4), 1244-1252, DOI: 10.2136/sssaj2010.0238.
- Regalado, C.M., Ritter, A., Rodriguez-Gonzalez, R.M. (2007), Performance of the commercial WET capacitance sensor as compared with time domain reflectometry in volcanic soils, VADOSE ZONE J 6(3), 1539-1663.
- Wu, J., Li, P., Qian, H., Fang, Y. (2014), Assessment of soil salinization based on a low-cost method and its influencing factors in a semi-arid agricultural area, northwest China, Environ Earth Sci., 71, 3465–3475, DOI: 10.1007/s12665-013-2736-x.