- EFN represents average sized commercial farmers that are trying to optimise production and biodiversity while minimising chemical use.
- Soil carbon sequestration as a tool for climate change mitigation is in its infancy – error bands for measurement are large and risks of carbon loss high.
- Much research is required to identify best practice matched with farm sustainability and profitability.
- Grazing permanent perennial pasture is the most effective way to fix carbon.
Costs associated with soil sequestration far outweigh benefits given current and predicted carbon prices.
- The most reliable way to sequester carbon on farm is strategic tree planting – on low production areas, windbreaks, biodiversity, salinity etc benefits.
- DPI should actively research biological farming claims – many people promote unproven technologies and products.
- Climate change is reducing soil carbon levels around the world – eg NZ and UK.
Australia will be hit hard with climate change so the likelihood of maintaining soil carbon at current levels here is very low.
- Australian soils are poor, the climate is highly variable and hot, growing seasons are short and rainfall is low.
- For the above reasons soil carbon offsets under the Kyoto 100 year rules would be too risky for farmers to agree to.
- Suggested reading: Soil carbon sequestration under pasture in Australian Diary Regions prepared for Dairy Australia; Dr David McKenzie in conjunction with Dr Warren Mason. Project MCK13538. This document reviews many relevant papers and summarises findings.
Actions that EFN members are undertaking to increase soil carbon sequestration.
Environmental farmers are passionately interested in keeping-up a good supply of organic matter to the soil ecosystem. As outlined in our submission, organic matter (from plant materials) provides the energy flow into the soil. This energy powers the biological functions of the soil, - functions which are directly related to health. Of course, the biological functions consume a large part of this organic matter – an activity which itself improves soil health (leading to: soil mixing; increasing biopores; improving water holding capacity; recycling cycling nutrients; and protecting against erosion) - but small quantities of this organic matter eventually end up as humus which is resistant to further predation by soil organisms. It is this humus which plays an invaluable and permanent role in promoting and stabilizing soil structure and will be primarily responsible for long term increases in soil carbon.
Some examples of best practice are:
- Adequate fertiliser application for the pasture/crop type, soil, climate regime including trace elements and mineral balance (exchangeable cations, pH).
(maximizing plant growth)
Noting that native pastures require less fertiliser than introduced pastures.
- Maintenance of adequate ground cover.
(avoiding exposure of soil to eroding or compacting elements : be they weather, sunlight, machines, or hard footed stock)
- Planting deep rooted perennial pastures/crops.
(enabling greater root exploration of water reserves and hence increasing period of plant growth and depth of carbon sequestration)
- Minimal soil disturbance by direct drilling pastures and crops.
(minimising damage to soil structure while at the same time reducing exposure and oxidation of organic matter)
- Controlled traffic.
(avoiding compaction of the largest parts of a paddock by confining the effects of wheel traffic to very defined parts of a paddock)
- Stubble retention.
(no wastage of organic matter for energy supply and protective cover to soil surface)
- Crash grazing, controlled grazing on hills, rotational grazing.
(not allowing pastures and vegetation to drop below a point when recovery is compromised and minimising trampling damage to soil structure)
- Pasture/cropping to maximise growing periods, maintain ground cover, and reduce chemical use.
- Deep ripping to remove physical barriers to root penetration (compare with removing chemical barriers with say lime or gypsum)
In summary soil disturbance is not necessary bad, but it is the scale of disturbance which is bad. Soils are quite dynamic (activity of worms, termites, scarabs, roots, micro organisms and so on). But cultivation is a wholesale disruption without any of the redeeming inputs of exudates and faeces. The benefit of cultivation is seed-bed preparation (not sure about weed control). The dis-benefits of regular cultivation in old and fragile soils must severely outweigh the benefits.
Any agricultural benefits and financial costs associated with these actions:
Benefits:
Increased soil carbon improves soil health and water retention ability. Less runoff from storms and rain events recharges aquifers and improves river health (reduced N and P in water and salinity abatement). Reduced gully and surface erosion. Improved farm viability as production increases you reduce fixed cost component of your business.
Costs:
The costs are opportunity costs, some re-tooling costs and indeed cost associated with developing an understanding of the best ways to manage the particular production regime, with the particular soil and land assets, subject to the local (and variable) climatic conditions.
The rate of soil carbon sequestration is increased by maintaining adequate ground cover, that is by taking off less product in the form of milk, grain wool, meat etc. There is a short term cost if you are to improve the soil carbon levels. The opportunity costs are the trade-off balances. Higher production of a particular commodity can mean lower rates of organic matter retention.
Retooling cost are those to do with the development/purchase of machines/technologies or changing farm infrastructure (subdivision, water reticulation etc) to undertake changing practices
Carbon trading equity issues:
Different soil types have a large variation in carbon retaining ability so the issue of inequity exists in a natural sense. If a farmer was to run down his soil carbon deliberately he or she would be doing economic damage to themselves. Conversely a farmer with high organic carbon levels is reaping the benefits of best practice. There is no inequity if soil carbon is not part of the CPRS.
If we were to proceed with a soil carbon trading system, one possibility for consideration is a soil carbon entitlement difference. Particular soils in a particular environment could be assigned a FAQ organic matter level. Farmers above this level could trade their surplus (in a bookkeeping sense) with carbon banks. People below this level could be entitled to a payment for raising their levels, although the rate of reward should be lower until they reach the FAQ. Until we have simple ways of accounting soil carbon, this is impractical – but the equity issue principle is that we must reward those who have been responsible irrespective of the dangling carrots.
Using the EBMP benchmarking tool and incorporating soil carbon levels in farm gross margin accounting systems:
Does this assume a CPRS scheme with soil carbon included? Not sure what advantage this is except for helping convince financers of your business skills.
If soil carbon management is to be a rewardable activity, and we cannot base it on a simple, repeatable and accurate soil test, then it will have to be based on “proxys”. EBMP could be an invaluable tool for this.
The need for education of farmers in relation to benefits of soil carbon sequestration:
Anecdotally from my landcare background there is increasing interest in biological and organic farming techniques, soil health workshops, perennial pasture establishment and improved plant varieties, climate change adaption, improved cropping techniques etc showing a high level of interest in the mechanism of soil carbon sequestration already. These workshops have been organised by DPI, Grower Groups, Landcare Networks and Industry. The DPI needs to keep doing what it already is doing; looking for market gaps in extension and organising events, encouraging private consultants and researching much more on soil biology and carbon sequestration and the effects climate change will bring.
Low emission farming is almost an antonym of industrial farming. Low emission farming will be clearly more sustainable in a carbon based economy. This will mean much more strategic use of high energy inputs (apart from sunlight), as well as maximising the energy use from the sun via photosynthesis. Curiosity, experimentation and observation will be characteristics of successful farmers in such an environment. It is an important role of society (and thus the government) to facilitate and encourage this – and the parallel development of techniques to cope.
How can Victorian Government support the benefits of soil carbon sequestration:
As per our submission via CMA’s, DPI’s Future Farming Program, more objective encouragement of trials of Biological Farming methods and materials comparing with traditional practices, research into soil carbon sequestration processes, etc
We need some more knowledge. First on the different capabilities of our portfolio of Victorian soil/landscape associations (including levels of organic carbon accumulation possible in stable land use systems), and second on what techniques are available for each of these to increase the rate of accumulation of durable soil organic carbon.
We need the social and economic systems to enable farmers the time, economic security and where-with-all to manage their land for the benefit of all society – to say nothing of the planet
Final Message
THE GOAL OF ENVIRONMENTAL FARMERS - TO MAXIMISE PHOTOSYNTHETIC ACTIVITY FOR THE MAXIMISATION (NOT OF FOOD PRODUCTION but) OF ECOSYSTEM SERVICES.
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