Soil moisture sensors that measure the moisture tension in the soil are read out with the soil moisture meter Watermark. The measuring principle is similar to that of the gypsum block system. The special sensors, however, do not dissolve in the soil and have a more consistent distribution of pores so that more accurate measurements are possible.
Measuring range
The soil moisture sensors, which have a measuring range of 0-200 kPa (0 - 200 cbar), can be used individually or in combination with a PVC tube (in various lengths) for measuring the moisture tension. The condition for reliable measurements is the optimal contact between sensor and soil. Using the special auger the holes are pre-drilled so that the soil moisture sensors can be placed at various depths. The sensors are buried permanently and have an average life of 3-5 years.
By using a soil temperature meter the temperature measurement can be set in the soil moisture meter allowing for temperature correction. The electrical resistance is converted by the soil moisture meter into moisture tension in kPa. The soil moisture sensors can be used as a replacement for tensiometers in most agricultural and landscape irrigation environments. If a series of soil moisture measurements are required the soil moisture sensors can be connected easily to a datalogger.
Benefits Soil moisture measuring system Watermark
- Cheap but serious measuring instrument
- Results directly expressed as soil suction
- The range allows measuring trees and dry crops
- Also good for irrigation advice
- No field maintenance of probes
- Stable long-lasting salinity insensitive probes
- Easy read-out with a simple cheap instrument
- Temperature can be corrected
- Cheap simple 8 ports datalogger available
Remarks
- Probes need good contact with soil
| Maximum measuring depth | > 100 cm |
| Measuring accuracy | ± 5% |
| Measuring range | 0...2000 hPa |
| Reading accuracy | 0.5% |
| Registration type | logging |
| The volume of material needed | 30 ml |
| Applications | Irrigation research, Soil moisture measurements |
