4. Sir Paul Edmund Strzelecki
Soil samples collected 1839 -1843
41 samples
10 highest ranking soils had OM levels
from 11% to 37.75% (average 20%)
10 lowest ranking soils had OM levels
from 2.2% to 5.0% (average 3.72%)
5. The organic carbon content
of most Australian topsoils is
now 50-80% less than the
original level – mostly as a
result of the loss of the soil
itself
17. Mineral depletion in vegetables
1940 - 1991
Copper reduced by 76%
Calcium reduced by 46%
Iron reduced by 27%
Magnesium reduced by 24%
Potassium reduced by 16%
Source: UK Ministry of Agriculture
18. Mineral depletion in meat
1940 - 1991
Iron reduced by 54%
Copper reduced by 24%
Calcium reduced by 41%
Magnesium reduced by 10%
Potassium reduced by 16%
Phosphorus reduced by 28%
Source: UK Ministry of Agriculture
19. Australian fruit and vegetables
1948 1991
Potatoes Calcium 27 mg 3 mg 89%
Broccoli Magnesium 160 mg 29 mg 82%
Carrots Vit. A 25,000 IU 91 IU 99.6%
Apples Vit. C 25 mg 5 mg 80%
It is possible to buy an orange today that
contains ZERO vitamin C.
20. It’s not only the quality of
the product that has
gone downhill
Farmers are no longer
making a profit either
22. Agricultural Debt Levels (NZ)
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
50,000
Dec
1990
Oct
1991
Aug
1992
Jun
1993
Apr
1994
Feb
1995
Dec
1995
Oct
1996
Aug
1997
Jun
1998
Apr
1999
Feb
2000
Dec
2000
Oct
2001
Aug
2002
Jun
2003
Apr
2004
Feb
2005
Dec
2005
Oct
2006
Aug
2007
Jun
2008
Apr
2009
Feb
2010
MillionsNZD
50
$50
$25
$0
1990 2000 2010
24. SOIL CARBON is the key driver for the
nutritional status of plants – and therefore
the mineral density in animals and people
SOIL CARBON is the key driver for soil
moisture holding capacity (frequently the
most limiting factor for production)
Soil carbon is the key driver for farm profit
35. There would be sufficient
length of mycorrhizal hyphae
in the top 10cm of just four
square metres of healthy
grassland soil to stretch all the
way around the equator
(Leake et al, 2004)
36.
37.
38. Soil nutrient levels (0-30cm) from between and within
Gatton Panic crowns, Binnu, WA, May 2009
________________________________________________________
Between Within Change
Organic carbon (%) 0.24 1.04 433%
Phosphorus (Colwell ppm) 21 71 338%
Potassium (Colwell ppm) 44 150 341%
Sulphur (ppm) 2.7 7.9 293%
pH (CaCl) 5.8 7.1 1.3 units
_______________________________________________
Source: Tim Wiley, WA Department of Agriculture and Food
(increased soil C = sequestration of 123tCO2/ha)
39. It has been widely promoted by CSIRO
Division on Plant Industries that to
increase levels of soil carbon requires the
application of nutrients to soil and
increased fertiliser costs
This is contrary to what is observed in
practice
The carbon and nutrients MYTH
40. Increased C increased pH, CEC
Increased C increased availability of P,
Ca, K, S
Increased C increased availability of Cu,
Zn, Fe, Mo, B
Increased C reduced availability of Na,
Al
The carbon and nutrients TRUTH
41. Microbes vs fertilisers
Very few nutrient deficiencies are absolute
– most are functional (due to poor soil
structure and/or lack of microbial
diversity)
Agrochemicals and synthetic fertilisers
significantly alter microbial populations
and the functional dynamics of soil
44. 1. Stop killing the microbes that are trying
to live in your soils (use biology friendly
fertilisers in place of high analysis N, P)
2. Improve plant root systems through
species selection (perennial rather than
annual) and above-ground management
45.
46.
47. MAP MAP + Triad Mineral Fert
Root/Shoot Ratio 0.184 0.282 0.112 0.151 0.689 0.976
Biomass - Increasing Soil OM & OC
F Wt - Roots vs Shoots
gFwt 31.95
29.88
27.23
30.24 30.53 31.05
21.02
4.58
3.05
8.44
5.88
31.81
0
10
20
30
No
Microbes
+ Microbes No
Microbes
+ Microbes No
Microbes
+ Microbes
F Wt Roots
F Wt Shoots (g)
% Biomass Root 17.7 22.0 10.1 13.4 40.8 49.4
Root Surface Area 302 392 127 184 978 4021
Triadimefon
+/- WMF Ag blend
microbe seed
dressing
48.
49.
50.
51.
52. Soil has always been
Australia’s biggest export
Even today, soil loss is greater
than agricultural production
For example, average wheat yield 1.2 t/ha
Average soil loss on wheat farms 15 t/ha
53. How can we turn that
around and rebuild
healthy, porous,
carbon-rich topsoil?
75. The difference in land
management techniques
Adjoining paddocks March 2010
Planned grazed and
Pasture Cropped
Continuously grazed
and fertilised annually
90. Soil Nutrients
Avail Total
Ca 234% 270%
Mg 110% 152%
Zn 250% 195%
Cu 185% 215%
B 150% 161%
Si 116% 113%
N 103% 151%
P 102% 155%
K 198% 150%
S 92% 159%
Fe 87% 130%
Na 45% 88%
Al 28% 140%
91. Soil Integrity Index
Accreditation system for soils based on
Microbial diversity
Soil water holding capacity
Soil carbon content
Simple code on food labels, eg star system
(one, two or three stars)
92. Food quality labelling
The urban population could have a
major impact on soil health through
food choices, if guided by labelling
based on the ecological integrity of
the production system
100. CSIRO report p.42
"A potentially troubling, but
also somewhat intriguing,
issue is that there is no readily
apparent explanation for some
of the very large SOC gains
being anecdotally reported."
101.
102.
103.
104.
105.
106.
107.
108.
109.
110.
111.
112.
113.
114.
115.
116.
117.
118.
119.
120.
121.
122.
123.
124.
125.
126.
127.
128. From Dlugokencky et al (2009). Yearly
variations in methane from 1983 to 2009.
Measurements in parts per billion.
