Using Time Temperature Domain Reflectometry (TDR) a precise soil humidity sensors as a reference to improve irrigation adjustments on soil crops
The simplest procedure in irrigation scheduling is based on determining the relative values of field capacity from a saturation episode, like a heavy rain. With these values and taking into account the trends in soil moisture content during the previous 4-5 days, appropriate irrigation schedule are established Several tools are nowadays available for this purpose, sensors based on Time Domain Reflectrometry (TDR), provides accurate and very intuitive information of soil water status with relatively low maintenance. TDR is becoming more and more widespread for its simplicity of operation and use and accuracy, within 1 or 2% of volumetric water content. TDR measure the soil water content indirectly by determining the bulk dielectric constant by measuring the time it takes for an electromagnetic pulse (wave) to propagate along a transmission line that is surrounded by the soil. The TDR probe usually consists of 2-3 parallel metal rods, different lengths are available also, that are inserted into the soil acting as waveguides. The rods are connected to a display that allows to get directly the value of soil moisture content. Loggers for continue measure can be used as well. TDR is a non-destructive and relatively less labour intensive technique; the instrument used could be portable o permanent, easy to install, rapid to take measure and safe to operate. These sensors are especially suitable for short root crops due their small root depth. However, soil salinity or highly conductive heavy clay contents may affect TDR operation. In addition, the volume explorated by the sensor is relatively small. By other way, TDR sensors usually have a high cost that could block their introduction into the commercial agriculture.
Transfer of INNOvative techniques for sustainable Water use in FERtigated crops
Completed | 2016-2018
- Main funding source
- Horizon 2020 (EU Research and Innovation Programme)
- Geographical location
- Belgium