Background

Increasing soil carbon levels has been raised as one of the methods we can utilise to offset carbon emissions. Soil carbon comes in 2 forms, inorganic forms such as calcium carbonate (lime) and organic forms. Soil organic carbon (SOC) is the carbon derived from plant residues in soils; living roots; biological organisms; and decomposing, decomposed and burnt material of varying sizes but does not include fresh undecomposed plant materials on the surface. SOC is a critical factor in soil health. The benefits of improving SOC levels include increased soil fertility, water holding capacity and improved soil structure. Improved structure leads to increased infiltration of water with higher levels of plant available water and more stable soil particles thereby reducing the potential for wind and water erosion. All of these lead to improved productivity, profitability and resilience to soil degradation.

The amount of organic carbon that can be stored in a soil is determined by:

• The amount of input of organic material into the soil – the amount of plant residue grown and retained, the form of vegetation, and
• The amount of carbon retained by the soil – largely determined by the soil properties soil clay content [%] soil depth and bulk density.

How Rural Solutions SA delivers value in Soil Carbon projects

Rural Solutions SA has been involved in soil modification projects for over 20 years and has an extensive network with landholders, contractors and NRM bodies with many active demonstration and trial sites. We have been integral to the development and provision of best practice guidelines for soil modification and are the leader in this field, not just in South Australia, but nationwide.

• 2008/9 – DENR Pilot project comparing selected soil types under different landuses, including cropping to pastures, cropping to native vegetation.
• 2009-12 – DENR/CSIRO National Soil Carbon Project – sampling 120 sites benchmarking soil carbon on red brown earths in the mid-north and Eyre Peninsula regions.
• 2010/11 – CSIRO National Soil Carbon and pH monitoring – sampling of 4 sites (2 in the mid-north and 2 in the Murray Mallee).
• 2008-12 – Various projects through the Advisory Board of Agriculture, Farming Systems Groups such as LEADA and Mackillop Farm Management Group.
• 2012-13 – DENR/CFOC 20: Carbon Challenge –  carbon audit of 100 sites on modified soils and trials and demonstrations of best modification practice .
• 2011 Currently working with Adelaide, Murdock, James Cook Universities, DPI Vic, WA Ag to develop a major Carbon Farming Initiative project.

Read more about Soil Carbon ...

How does carbon get into the soil?

Techniques to improve soil carbon?

For more information contact: David Davenport