With harvest underway, just a friendly reminder: don’t forget to either clearly mark the position of your soil moisture probes in your paddocks or remove them prior to harvest!
Foundation for Arable Research’s technology manager Chris Smith says that if you need to leave them in the ground, to continue monitoring soil moisture, then identify locations with high vis flags on fibreglass poles above the crop canopy. This can save accidental damage to the probe, the telemetry or even the combine.
If removing the probes, disconnect the telemetry and remove the battery for winter storage, if they aren’t going to be reinstalled straight away. When digging the probe up, follow the cable back from the telemetry unit to find the location of the probe, which could be several metres away.
Depending on the make and model of probe the top could be underground. So, carefully remove the top soil above the probe head, which could be around 30mm+ below the surface.
Multi-level sensor probes are generally 30-90cm long. Use something like a screw driver and carefully clear the soil away from around the top 15cm of the probe.
Depending on the soil type, it may pay to pour water in the hole you have made around the top of the probe. Gently rotate the probe and it should come out easily. If not, let the water penetrate the soil around the probe to release it. Some probes will need to be “unscrewed/rotated” from the soil profile; discuss specific techniques required with your supplier.
Never use a spade or similar to lever or dig the probe out unless your supplier stipulates it. Likewise, don’t put too much pressure on the probe head to pull it out – if it won’t come out, keep digging down around the probe.
Figure 1: Image source Sentek, Crop X and AquaCheck
Tell your provider that the probe has been removed and they can close down the soil profile for you on the monitoring platform. This will ensure your probe will be in a good condition for reinstallation/monitoring in your next crop and your data is intact.