POSITIVE LIST ADVICE TO THE MINISTER FOR THE ENVIRONMENT
The Domestic Offsets Integrity Committee (DOIC) considers that the following activity
is suitable for inclusion on the positive list for the reasons outlined below.
Sequestering carbon in soil in grazing systems.
The DOIC assesses positive list proposals against the following criteria.

Does the proposed positive listing fall within the scope of the Carbon Credits (Carbon
Farming Initiative) Act 2011?

Is there a reasonable prospect that the offsets projects covered by the positive listing
will avoid relevant emissions of greenhouse gases or sequester carbon in living
biomass, dead organic matter or soil?

Are the offsets projects covered by the positive listing likely to be ‘additional’ (i.e.
would they be undertaken in the absence of the incentive provided by the Carbon
Farming Initiative?) and, in particular, having regard to section 41(3)(a) and (b) of the
Carbon Credits (Carbon Farming Initiative) Act 2011:
o
o
are the projects covered by the positive listing not common practice; and
if they are common practice, would they be in the absence of the incentive
provided by the Carbon Farming Initiative?

Are there perverse impact risks associated with the offsets projects covered by the
positive listing and can these be reasonably managed?
A.
Within the scope of the legislation
Section 41(1)(a) of the Carbon Credits (Carbon Farming Initiative) Act 2011 provides for
regulations to be made specifying a ‘kind’ of project. The DOIC considers that the scope of
this provision is sufficiently broad to enable projects to be specified in the regulations on the
basis of both their inherent characteristics (grazing system) and abatement outcomes
(sequestration of carbon in soil). In addition, the sequestration of carbon in soil in grazing
systems is covered by the definition of a ‘sequestration offsets project’ contained in section
54 of the Act.
B.
Abatement potential
Soil carbon levels are generally either stable or declining across Australia’s agricultural lands,
including lands where grazing occurs (Department of Climate Change and Energy Efficiency
2013; State of the Environment Committee 2011; Hook 2011).
Soil carbon stocks are a function of the balance between soil carbon inputs and losses.
Inputs are affected by factors that control plant growth, and the deposition and subsequent
conversion of plant biomass into soil organic matter. Losses are affected by factors that
control the rate at which soil organic material is decomposed and returned to the
atmosphere as carbon dioxide.
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There is potential to build soil carbon in grazing systems by improving pasture production
and managing grazing pressure to increase inputs of plant biomass into the soil. Strategies
to build soil carbon in grazing systems could include pasture improvement through
fertilisation, irrigation or species selection and managing the timing, intensity and frequency
of grazing. For the purposes of this positive list proposal permanent destocking is not
considered to be a form of managing grazing systems.
A review of soil carbon sequestration potential for Australian agriculture by Sanderman et
al. (2010) concluded that:
In general, grazing at appropriate stocking levels will maintain or
enhance soil C [carbon] stocks (Conant et al. 2001) due to positive
effects on vegetative growth (LeCain et al. 2000; McNaughton et al.
1996; Sims et al. 1978) and turnover of both above-ground shoots and
below-ground roots (Nyborg et al. 1999; Schuman et al. 1999; Sims et al.
1978). However, many of the details are not well understood (Ingram et
al. 2008; Parton et al. 2001) and mixed results are common (Derner et
al. 2006; Pineiro et al. 2009).
The same review found that pasture improvements, such as fertilising with phosphate and
lime, irrigation and increasing the proportion of perennial grasses, could also result in
increases in soil carbon stocks. The review concluded that the potential for increasing soil
carbon was likely to vary across different soil types and climates.
The National Soil Carbon Research Program took single point-in-time measurements of soil
carbon from properties across Australia where a range of different grazing management
systems operated.
Soil type and climate were the strongest determinants of soil carbon stocks in most regions.
While other management and farming history factors were implicated in the observed
variation in soil carbon stocks, the high site to site variability meant that no statistically
significant relationships between soil carbon stocks and management practice could be
developed from the data currently available.
Although this research suggested that it may be possible to build soil carbon through
pasture species selection and grazing management, it also highlighted the difficulty of
identifying particular management strategies that reliably build soil carbon stocks across a
range of environments. To be confident that carbon is being sequestered in soil, temporal
variations in site-specific soil carbon stocks and their associated uncertainty would need to
be measured or modelled.
Measurement-based approaches can be used to demonstrate the impact of an activity on
soil carbon levels in circumstances where there is insufficient information to predict the
relationship between the activity and soil carbon levels. Project proponents could
potentially implement any management strategy for grazing systems that suited their
particular circumstances and, provided that the abatement calculation addresses the impact
of other factors on soil carbon stock changes (for example, the impact of rainfall variation),
measurement-based approaches could be used to quantify changes in carbon in soil induced
through management of grazing systems. The abatement calculation would also need to
take into account the potential impact of changed management strategies on other
emissions sources, such as nitrous oxide emissions.
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Identification of particular strategies that build soil carbon is therefore not necessary for
methodologies based on direct measurement of soil carbon stocks, as any sequestration can
be quantified through subsequent measurement and reporting. As a result, the activity can
be broadly described on the positive list and, provided the methodology adequately
controls for the impact of non-management factors that affect soil carbon stocks, the
integrity of credits issued in relation to the relevant projects can be assured.
Where a project required generic emission factors, such as the use of model-based
approaches, a specific management strategy would need to be identified and the
relationship between the activity and soil carbon outcome would need to be quantified upfront. By contrast, using a measurement-based approach, the impact of management
strategies on soil carbon stocks in grazing systems can be demonstrated at the project
reporting stage.
In summary, there is evidence to suggest that additional atmospheric carbon may be
sequestered in soils in the form of organic carbon by altering management of grazing
systems.
C.
Common practice
The proposed positive list activity is a broad group of management actions coupled to an
abatement outcome (sequestering carbon in soil). Consequently, the DOIC considered
evidence of soil carbon trends in grazing management systems across a range of
environments when assessing whether or not the activity was common practice.
Soil carbon levels are generally either stable or declining across Australia’s agricultural lands,
including lands where grazing occurs (Department of Climate Change and Energy Efficiency
2013; State of the Environment Committee 2011; Hook 2011). Given this, it is reasonable to
conclude that it is not common practice to increase soil carbon sequestration in grazing
systems.
D.
Perverse impacts
The DOIC notes that, given the uncertainty surrounding which management practices are
likely to increase soil carbon stocks, there is the potential for landholders to undertake
grazing system offset projects without fully appreciating the associated financial risks. While
this is possible, the DOIC believes these risks can be adequately managed through the
methodology and relevant stakeholder engagement processes.
The DOIC does not believe there are any other significant perverse impact risks associated
with the proposed positive listing.
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References
Conant RT, Paustian K, & Elliot ET (2001) Grassland management and conversion into
grassland: Effects on soil carbon. Ecological applications 11, 343-355.
Department of Climate Change and Energy Efficiency (2013) Australian National Greenhouse
Accounts National Inventory Report 2011 2 DCCEE, Canberra.
Derner JD, Boutton TW, & Briske DD (2006) Grazing and ecosystem carbon storage in the
North American Great Plains. Plant and Soil 280, 77-90.
Hook R (2011) Assessments of status and trends in soil organic carbon workshop – summary
notes. Report prepared for the Australian Government Department of Sustainability,
Environment, Water, Population and Communities on behalf of the State of the Environment
2011 Committee. Canberra: DSEWPaC, 2011.
Ingram LJ, Stahl PD, Schuman GE, Buyer JS, Vance GF, Ganjegunte GK, Welker JM, & Derner
JD (2008) Grazing impacts on soil carbon and microbial communities in a mixed-grass
ecosystem. Soil Science Society of America Journal 72, 939-948.
LeCain DR, Morgan JA, Schuman GE, Reeder JD, & Hart RH (2000) Carbon exchange rates in
grazed and ungrazed pastures of Wyoming. Journal of Range Management 53, 199-206.
McNaughton SJ, Milchunas DG, & Frank DA (1996) How can net primary productivity be
measured in grazing ecosystems? Ecology 77, 974-977.
Nyborg M, Malhi SS, Solberg ED, & Izaurralde RC (1999) Carbon storage and light fraction C
in a grassland Dark Gray Chernozem soil as influenced by N and S fertilization. Canadian
Journal of Soil Science 79, 317-320.
Parton WJ, Morgan JA, Kelley RH, & Ojima DS (2001) Modelling soil C responses to
environmental change in grassland systems. In The potential of U.S. grazing lands to
sequester carbon and mitigate the greenhouse effect (Ed. RF Follett) Lewis Pub., Florida.
Pineiro G, Paruelo JM, Jobbágy EG, Jackson RB, & Oesterheld M (2009) Grazing effects on
belowground C and N stocks along a network of cattle exclosures in temperate and
subtropical grasslands of South America. Global Biogeochemical Cycles 23.
Sanderman J, Farquharson R, & Baldock J (2010) Soil carbon sequestration potential : A
review for Australian agriculture, CSIRO, Canberra.
Schuman GE, Reeder JD, Manley JT, Hart RH, & Manley WA (1999) Impact of grazing
management on the carbon and nitrogen balance of a mixed-grass rangeland. Ecological
Applications 9, 65-71.
Sims PL, Singh JS, & Lauenroth WK (1978) Structure and function of 10 western North
American grasslands. Journal of Ecology 66, 573-597.
State of the Environment 2011 Committee. Australia state of the environment 2011.
Independent report to the Australian Government Minister for Sustainability, Environment,
Water, Population and Communities.
Canberra: DSEWPaC, 2011.
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