HEAVY CLAY SOIL WETTER TEST CONDUCTED BY JOHN BROWN FOR USE IN DRIP
TEST DATE 13/3/2006. LIGHT RAIN LAST RECORDED MORE THAN 3 WEEKS EARLIER.
Set up:- Dug trenches with crow bar measuring 300 mm x 80 mm x 450 mm deep. Trenches set 600 mm apart in line with normal dripper spacing. Both test drippers set back 150 mm from centre edge of each trench.
Dripper flow rate set at 2 litres per hour - gravity fed.
Test set to drip for two and a half hours, which is five litres for each dripper.
Wetting agent added to first 500ml of water for LEFT trench dripper. Water only for RIGHT trench dripper.
Cost of agent 1/2 a cent.
White PVC pipes played no part in tests.
It was expected LEFT dripper would produce an upside down Turnip profile to depth of trench given the drips started 150 ml from trench edge. I expected the moisture to break through the side of the trench at some depth below the surface, maybe 1/3 to a 1/2 way down hole. I expected water from the plain water drip, would pool and spread on the surface and be blocked by the clay at a shallow depth.
THE FOLLOWING PHOTOS ARE IN TIME SEQUENCE OVER 3 HOURS.
TRENCHES DUG TO 450 mm DEPTH
LEFT TRENCH DRIPPER WITH WETTER ADDED
RIGHT TRENCH DRIPPER WITH WATER ONLY
RIGHT TRENCH SHOWING NO EVIDENCE OF WATER AT TOP EDGE OR AT DEPTH
LEFT TRENCH WITH WETTER SHOWING FIRST SIGN OF MOISTURE AT ABOUT 200 mm DOWN + SURFACE
TRENCH LAY OUT.. LEFT DRIPPER HAS WETTER AGENT ADDED. RIGHT DRIPPER WATER ONLY.
LEFT TRENCH WITH WETTER SLOWLY SPREADING
LEFT TRENCH WITH WETTER SLOWLY SPREADING AND SPREADING ON TOP SURFACE
LEFT TRENCH WITH WETTER SPREADING FURTHER AND 1ST SIGN OF WORM GETTING TOO WET
RIGHT TRENCH SHOWING SPREAD OF MOISTURE ON SURFACE BUT NONE DOWN HOLE
LEFT TRENCH WITH WETTER SPREADING FURTHER AND WORM ON THE MOVE
LEFT TRENCH WITH WETTER SPREADING TO BOTTOM AND BEGINNING TO WRAP RIGHT SIDE
RIGHT TRENCH STILL ONLY SHOWING WATER AT SURFACE
LEFT TRENCH WITH WETTER REACHING BOTTOM AND WRAPPING BOTH SIDES AT 450 MM
CONCLUSION:- Applied through dripper irrigation is a proven success. I have little doubt the use of this particular
wetting agent will save huge amounts of water as much as 50%, allowing water to wet the soil to great depth
encouraging roots to depth where vines and plants will benefit with a constant source of water, minerals and nutrients.
The vines will not suffer the problem of burnt roots during drought conditions and where roots only develop along the surface.
I am not at liberty to divulge the components of this wetter and have been offered the rights for use in vineyards.