DSC is eligible for the “Carbon Farming Initiative”
The Clean Energy Regulator, which administers the Carbon Credits (Carbon Farming Initiative) Act 2021, has officially declared Deep Seedbed Conditioning as eligible to accumulate Australian Carbon Credits in the Carbon Farming Initiative. DSC fits the criteria of:
- Newness (because it is a new technology that is only just becoming available to Australian farmers); and
- Its action “modifies landscape ….. features to remediate land”, and is implemented “for …… surface water management, drainage, …… or alleviating compaction”.
The technology conserves (to the point of preserving) the structure and mass of enlarged root systems in a deepened and stabilised root zone, created with the least possible soil disturbance, and so also meets the reduced soil tillage requirement.
How is DSC able to easily increase soil carbon ?
The design and operation of the DSC machine is based by the truism that:
Once the physical condition of plant root zones is optimised,
improved soil biology, fertility, water use efficiency
and crop productivity will follow.
The DSC machine slices through soil and roots at a depth of about 250 – 300 mm with angled, flat blades that lift, open and drop soil without horizontal or vertical displacement (which mimics airflow over the upper surface of an aeroplane wing). This action leaves the entire structure and mass of enlarged root systems undisturbed in a loose soil matrix.
The use of a DSC machine allows farmers to “farm” plant roots (and the carbon within them), as well as the population of soil biology that surrounds roots, whilst they apply normal farming practices (Figures 1 – 4).
How does DSC increase profitability ?
The practice of Deep Seedbed Conditioning increases cropping profit by reducing operational costs and increasing income.
The operational costs DSC reduces are:
- Energy costs: The DSC machine has a very low draft and uses less fuel.
- Fewer operations: Consolidation of loose tilth is minimal (retained roots act as a reinforcing mesh), and a fine seedbed is almost always created by a single pass of the machine.
- Irrigation applications are faster and require less water.
- Fewer applications of herbicides and pesticides are required, because the soil is well-aerated and drained, which minimises germination of weed seeds and largely precludes populations of soil-borne plant pathogens.
- Labour costs are reduced.
Income is increased by:
- Larger yields in dry seasons because of improved drought resilience – root zones have more plant available moisture and plants extract more water;
- Larger yields generally, even on the highly fertile soils black clays of the Darling Downs in Queensland; and
- Increased root and shoot growth sequester increased amounts of soil carbon, which can be sold as Australian Carbon Credit Units.
How soon will soil carbon increases be profitable?
The rate of increase in soil carbon depends on the amount of crop growth (particularly root growth), and this will vary with soil types, rainfall or irrigation amounts, soil fertility and the presence or absence of pests and diseases. However, compared to all other practices, DSC practice will maximise plant and root growth and hence soil carbon storage.
An example from field research provides a guide to the time required and the size of soil carbon increase DSC will deliver. Over a six year time span, on a 100 ha paddock in which annual crops of wheat, barley or canola were grown:
- DSC, compared to no-tillage (the current best practice), increased soil carbon in the 0 – 300mm depth layer by 48 per cent (Figure 2).
Expressed as Carbon Credit Units (CCUs, i.e., tonnes of carbon dioxide equivalents), this increase amounted to
- 94 tonnes per ha, or 9,400 tonnes per 100 ha, or 94,000 tonnes per 1,000 ha,
At the February 2022 Australian CCU price of $55 per tonne of CCU, this size of soil carbon increase represented;
- income supplements of $ 5,170 per ha or $ 517,000 per 100 ha , or $ 5,170,000 per 1,000 ha.
If the CCUs were sold on the international market at the May 2, 2022 value of New Zealand CCUs ($75.80 NZ or $69.50 AUD per tonne), the 1,000 ha value of these CCUs would be worth $6,537,000.
Will soil carbon continue to increase indefinitely?
No. All biological systems eventually develop a state of equilibrium in which the rate of inputs equals the rate of outputs, and there is some research that suggests that the maximum/equilibrium levels of soil carbon relate to clay content, rainfall or water supply.
However, a limit to the SIZE of and TIME to establish a new, maximum amount of soil carbon is unknown.
How is access gained to the Soil Carbon Market?
Access to the soil carbon market is gained by registering a project with the Australian Government Clean Energy Regulator, who will record it in the Energy Reduction Fund.
- the specification of a project area, which is the actual area on which you plan to impose a new form of soil management, such as DBL; and thereafter
- undertaking a soil carbon monitoring program that establishes the soil carbon content before the imposition of new management practices and reports to the Clean Energy Regulator on changed levels at least once every five years; and
- selling your carbon credits recognised by the Clean Energy Regulator to the government or on the open market through the Australian Carbon Exchange.
Note: An approved project carries an obligation of permanence. This means the new management practices must be applied for 25 or 100 years. However, the soil, water and environmental improvements delivered by DBL will mean this obligation will be of no consequence.
Details of recommended DSC machine manufacturers and field-scale research data supporting all the claims of improved soil conditions and productivity can be found by visiting the website of Maximum Soil and Water Productivity Pty Ltd at https://maxswp.com.au.