restoring soil carbon and landscape function will require us to change ourselves - david marsh
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CCRSPI Conference 2011Soils
Restoring Soil Carbon and Landscape Function will Require us to Change Ourselves
David Marsh, Boorowa. NSW
dmarsh1@bigpond.net.au
Looming Clashes
• Increasing fuel costs and scarcity• Increasing input costs• Dwindling biodiversity• Rising human populations•Water issues• A more variable climate
High Intensity Agriculture is Heavily Dependent on Fossil Fuel Energy Imports
Capital in the Landscape
Complex Communities Require 33% of Absorbed Solar Energy to Maintain
Structure and Diversity
The Simplified Agricultural Landscape Requires Annual Inputs of Purchased High Energy Products to Keep it in this
Disturbed Early- Successional State
Humans have been Spectacularly Successful at Diverting the Product of Photosynthesis -this has brought many Benefits, but also has Consequences
Dry Season 1982-83My Decisions Caused This
Landscape Losing CarbonPlanned Grazing in Foreground
3-1-2008
23 mm storm 13 -2-2008
Holistic Management and Planned GrazingMaking decisions that are Socially, Economically and Environmentally sound
Getting Control of Time is Fundamental to good Grazing Management
Plant Communities Like this Make Soila Carbon Sink
Soil with high SOC and 100% cover of living plants and litter, have high LFA
• Higher infiltration rates, lower run-off• Larger mass and diversity of biota•Not susceptible to wind erosion•Lower surface evaporation•Warmer in Winter, cooler in Summer•Higher water holding capacity •Becoming dominated by diverse perennials• Stable productivity, resilient•Higher effective rainfall
14 . 1 . 2011
46 days recovery 158 days recovery
71 days recovery 25 days recovery
8 . 2. 2011
Fenc
e lin
e
Community Dynamics49 plant species, 15 of them natives
February 2008
Fungi can pull Phosphorus out of the soil bank and communicate it direct to plantsThey are an important agent in recycling plant material
Plants still Photosynthesising December 2008
Annual Communities stop Growing in Summer
Tree Cover has increased from 3% to 20%Nine years of low rainfall, but no loss of soil cover No feeding of livestock at all
Soil carbon in a 7cm soil test, comparing the effects of planned grazing disturbance for ten years and no disturbance for 14 years in revegetation
Vegetation type pH soil/water %Total Nitrogen % Organic Carbon
7 cm sample
Available Phosphorus
Colwell
Grazed Pasture 5.4 0.34 3.22At BD 1.2 thisis 27t OC/haCO2e =100t
55.1
Grazed Pasture 5.9 0.24 2.76At BD 1.2 this is23.18 t OC/ha85.7 t CO2e
26
Ungrazed Revegetation
5.3 0.17 1.86At BD 1.3 this is16.9 t OC/ha
CO2e=62t
13.8
Ungrazed Revegetation
5.9 0.13 1.97At BD 1.3 this is
17.9 t OC /ha66 t CO2e
11.3
Regenerative FarmingPlanned grazingPasture croppingNo inorganic fertilizeron pasture, some with crop
The traditional approachSet stockingTraditional fertilizingTraditional cropping
82.9% Native perennialsHigh fungi and bacteria
88.1% Exotic annuals
Observations
• We want to change everything, but not change ourselves
•The unspoken assumption behind every proposed solution to the dilemmas that face humanity, is that when the proposed solution is applied we can go on living as we do; but how we live is really the problem
• Relying on GM, modification of rumen function and a bit of other tampering at the edges - is far too simplistic
• The natural world has adapted over the long lapse of ages to an ever changing climate; this is where we should be seeking answers
• Collaborating with innovative farmers early in the development of research programs would be an investment worth making
•Putting serious effort into learning how to practice agriculture without the reliance on fossil energy subsidies is very important right now
We all need to learn to love our landscapes
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