Soil matric potential - tensiometer (T4)

Parameter to be measured:

Soil matric potential

Method:

Tensiometer

Equipment:

T4 with external refilling option

Advantages:

• Very fast response
• Reliable
• Refilling possible without taking the probes out of the soil
• Great range: -1000 to 0 to 850 hPa

Disadvantages:

• Accuracy could be a disadvantage (+/- 0.25 kPa) according calibration sheet) depending on objective of study
• Some of installed tensiometers showed a stepwise output during small changes in soil matric potential (e.g. during drainage) in the order of 0.25 kPa

What to watch out for:

• Freezing conditions at fieldsite: at shallow soildepth (do not install year-round) and above-ground (insulate the shaft with PVC and isolation material)

Links

Projects that used the above equipment:

• PhD project WS10 HJ Andrews Experimental Forest

Other related web sites:

• http://www2.decagon.com/geo/T4
• http://www.ums-muc.de/fileadmin/files/Content/Katalog/5%20Tensiometer-ENG-R3.pdf