Soil Water Solutions


		This section lists a number of useful items which I have had to source for my laboratory. 1. Synthetic soil mixes - for use as contact materials, or when minimal chemical reaction is needed from a porous material. Includes how to make a silicate powder tension plate. 2. Moisture cans - polypropylene and metal. Needed for measuring the water content of soils at 100 degree C 3. Tension plates - for bringing soils to a set moisture suction potential. 4. Saran Resin - for coating soil aggregates to measure their volume 5. Pot water controller - to maintain the water content of pots at a fixed suction or water content 6. Transparent adhesive scales - for sticking onto glass or clear plastic tubes to convert them to ‘measuring cylinders’

	‘Synthetic soil’ mixes. Sometimes a soil-like porous material is needed for experimental work. Soil water solutions stocks (or can get) a large range of glass bead, clay mineral, or silicate based powders which can be mixed to produce specific properties. Price depends on the components of the mix - typically $10/kg Examples : (call with your needs!) a. Soil water sensor calibration mix. This material can be wet up to anywhere from 0 to 0.45 cc/cc water content and still remain non-sticky, friable and easily repacked around a sensor. b. Tension plate mix. If you need to make a tension plate to wet soils or drain them to 9 kPa (approx field capacity) then all you need is some tubing a plastic box and some of our tension plate mix.

Moisture cans : Small containers with fitted lids which can be placed in an oven at 105 degree C for soil moisture estimation.

Polypropylene tubs.

small 43mm diam x 28mm high (holds 30g soil) 50c each

large 43mm diam x 50 mm high (hold 50g soil) 70c each

These tubs usually have similar weights - an order of twice as many as you need will probably yield a set with the same weight within 0.02g . These tubs absorb a small amount of water 0.1% in air which is lost on drying - for very high precision work they should be pre-dried or kept in a dessicator

Aluminium tubs - these are made to order there is a set up charge of approx $600 then about $8 each.

We recommend that these be coated with enamel inside to prevent corrosion if alkaline soil is used and there is a compromise between a tight fitting lid and one which does not jam if grit gets into it.

Tension Plates : used to bring soils to a controlled moisture status. Soil water Solutions does not keep these in stock, however, we do make them to order from overseas ceramics. We are seeking a local ceramics supplier with the necessary skills. If you have old clogged or leaking tension plates we can refurbish the ceramic to as-new condition and fit it to a new base which can be dissassembled for cleaning.

New plates approx $2500

refurbishing approx $1000

Saran Resin : to water proof soil aggregates so their density can be measured.

The bad news : SARAN is no longer made by Dow Chemical.

The good news. Ordinary PVA house paint is a good substitute. Soil Water Solutions is researching a better substitute - call or email for the latest findings


		Pot water controller: Watering experimental pots is an onerous and exacting task - especially if the pot must be held close to a fixed water content. Our answer is to fix the pot at a particular soil water tension. Just place our pot water controller device in your pot connect it to a water reservoir below the level of the pot and the water content will be kept constant, drawing water from the reservoir as needed. Controllers are $15 each and operate best with the reservoir 0.5 m below the pot.



				Transparent Plastic adhesive scales: 0-80cm We use these to put scales on the permeamters we sell. They can be applied to glass or plastic to provide a measurable scale of water levels etc. Price $8 each incl GST