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OPTIMISED WATER MOBILITY THROUGH MODIFYING DISPERSION AND IMPROVING SOIL STRUCTURE BEHAVIOUR
Innovation in Water Movement and Soil Health
John Saad - Managing Director CHT Australia
1
OUR STARTING POINT
* https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0008/127277/Slaking-and-dispersion.pdf
Dispersion (the separation of soil into single particles) is governed by soil texture, clay type, soil
organic matter, soil salinity and exchangeable cations.*
INFLUENCED BY THE ADDITION OF CALCIUM
Slaking is the breakdown of a lump of soil into smaller fragments on wetting. It is caused when clay
swells and the trapped air bursts out. *
INFLUENCED BY THE ADDITION OF ORGANIC MATTER
2
CHEMISTRY OF SOIL CONDITIONERS
What might be used now What will also be used in the future
3
Poly cationic
Inorganic micro
emulsionsInorganic
Calcium
Sources
organic
Solutions
KCl
HOW TO MANAGE SURFACE TENSION
SURFACE TENSION OF
IRRIGATION SOLUTION
SURFACE TENSION OF
SOIL
5
OR
WHAT DOES THIS MEAN FOR CLAY SOILS
IF
THIS CONCEPT IS TRUE
THEN
WHAT SHOULD WE
EXPECT TO SEE
Greater infiltration of water
Greater Initial water uptake by soils
Greater water retention at depth
Better distribution of water through profile
Increased movement of soluble salts
Increased uptake of soluble salts by plants
Reduction EC at shallows
Increase EC at Depth
Enhanced soil friability
Reduced water discolouration
6
X RAY IMAGES OF DRY SODIC SOIL
7
Fine & Loose
Friable?
Coarse & compacted Treatment Control
CHANGES IN SLAKING ?
Change in Water retentions?
10
Soil ball made with
Aqua-Sil
Dry core of the soil ball
however homogenous
wetted from outside to
inside
FROM QUALITATIVE TO QUANTITATIVE PERSPECTIVES
Compare changes to slaking rate and water uptake
Compare changes to penetration resistance
Compare Changes in Water uptake and change in soil EC
11
ARTICULATING THE BENEFIT –INCREASED PLANT AVAILABLE WATER
12
0
2
4
6
8
10
12
14
16
18
0 3 6 9 12 15 18 21
w
e
t
w
e
i
g
h
t
i
n
g
r
a
m
s
Time in Minutes
Relative Slaking Profile Trend Lancewood #1
Control
Treatment
13
Sustained
Retention of
water and
soil
STRUCTURE
BEHAVIOUR
CHANGE
CREATES
OPTIONS
FOR
IMPROVED
SOIL
FERTILITY
0
5
10
15
20
0.00 1.50 3.00 4.50 6.00
W
e
t
W
e
i
g
h
t
o
f
S
o
i
l
Time in Minutes
Tamworth Pierce SW - ControlReplicate 1
Replicate 2
Replicate 3
Replicate 4
Replicate 5
0
5
10
15
20
0.00 1.50 3.00 4.50 6.00
w
e
i
g
h
t
o
f
s
o
i
l
Time in minutes
Tamworth Pierce SW - Treatment
Replicate 1 Replicate 2 Replicate 3
Replicate 4 Replicate 5
14
3 fold
increase
in water
uptake
Structural
behaviour
changed
significantly
0
2
4
6
8
10
12
14
0 10 20 30 40 50
g
r
a
m
s
o
f
s
o
i
l
Time in Minutes
Tamworth Otech SW - Control
Replicate 1Replicate 2Replicate 3Replicate 4Replicate 5
0
5
10
15
20
0 10 20 30 40 50
g
r
a
m
s
o
f
s
o
i
l
Time in minutes
Tamworth Otech SW - Treatment
replicate 1 Replicate 2 Replicate 3Replicate 4 Replicate 5 Replicate 6
ORGANIC VS INORGANIC POLYMER AFTER 1 YEAR APPLICATION
15
0
1
2
3
4
5
6
25 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600 625 650 675 700 725 750
Pre
ssu
re (
kPa)
Depth (mm)
Block 7 (Aqua-sil Soil Conditioner) Linear (Block 7 (Aqua-sil Soil Conditioner))
0
1
2
3
4
5
6
25 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600 625 650 675 700 725 750
Pre
ssu
re (
kPa)
Depth (mm)
Block 6 (SLS) Linear (Block 6 (SLS)) Linear (Block 6 (SLS))
DISTRIBUTION OF VWC AT DEPTH AT WERRIBEE
17
0
10
20
30
40
50
30 60 80
VWC
crop 3 may 2017
%
w
v
Aquasil N Aquasil S Control S Gypsum N Gypsum S Control N
DISTRIBUTION OF EC THROUGH DEPTH AT WERRIBEE
18
0
500
1000
1500
2000
30 60 80
EC
Crop 3 may 2017
E
C
m
s
Aquasil N Control S Control N Aquasil S Gypsum S Gypsum N
THE PATTERN IS CLEARPOORLY STRUCTURED HIGH SLAKING SOILS CAN BE REMEDIATED WITH AQUA-SIL
19
Increased initial up take of water
Slow the tendency to Slake
Become more Water Stable Structure
Increase Water Retention Potential
Sustain Water Retention
Reduced Penetration resistance
Increased Friability
THE CONCEPTUAL EQUATION FOR SOIL AMELIORATION
CONVENTIONAL
Gypsum 2 – 5 tonnes per hectare
Organic Matter 10-20 tonnes per hectare
Deployment Dry weather
Mechanical spreading
3-5 weeks application Window
Alternative Chemistry
200 ppm of growth zone
Or 30- 60 kilo grams per Hectare
Deployment through high dilution
fertigation system
20
CONCLUSION MORE PROOF?
21
Poly cationic Inorganic polymer emulsions with imparted surface
tension reduction properties are the new tool for soil health
management.
Calcium from Gypsum or Lime is no longer the only tool against
Dispersion
Organic Matter is no longer the only remedy to Slaking and water
retention for clay soils
Surface Tension and Charge balance are the levers to mitigate clay
swelling by controlling wetting rate of the substrate.
Aqua-Sil Provides the ability to manage soil surface tension and
soil charge balance through the fertigation and planting liquors.
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