Soil Moisture - Soil Solution Sampling

Soil Solution Sampling

Devices for soil solution sampling traditionally vary according to fashion.  We’ve moved away from this ‘flavour of the month’ attitude and have chosen just two types.

For general agriculture the ceramic cups are a good and cheap alternative but the material can affect the chemistry of compounds (such as Phosphorous, pH).

For more complex analyses the Rhizon method now has substantial positive following backed by good research.

With each method solution is extracted from the unsaturated (root) zone.  Each method has common parts: a porous cup, a tube and a connection to put the system under negative pressure.  It is the material of the porous cup which determines the quality and quantity of sample.

Micro Rhizon

Small diameter, 2.5 mm.

Low dead volume, 0.5 ml.

No ion-exchange properties.

Available as complete system

Competitively priced

Macro Rhizon

Consists of 9 cm porous material with a 4.5 mm diameter outside, strengthened by a glass fiber epoxy

Sampling is done with a syringe

Yield in water is about 10 ml/min.

The yield in wet soil is typically 7 ml in 0.1 - 2 hours, depending on soil properties.

Acceptable pH: 3 - 12, also depends on the corrosive properties of the soil solution.

Life expectation > 6 months

Can extract soil solution from depth > 10 m.

Can be extended using PVC pipe.

Samplers with ceramic cup

Good value

Sampling to different depths

For the determination of salinity measurements in the soil after irrigation or the application of fertilizers or manure; the washing in or out of various elements and compounds; pollution in the unsaturated zone, residual nitrate

Collects a large amount of soil moisture in a relatively shorter period of time.

Available in various lengths and diameters.