Organic Soil Carbon

Organic carbon improves soil quality through assisting many physical, chemical and biological processes. It influences soil colour, nutrient holding capacity, nutrient turnover and stability. Most WA soils never reach their full organic carbon storage potential as climate, soil characteristics and farming practice reduce plant residue returns to the soil. Carbon storage largely depends on soil type, climate and management practices. The more clay content a soil has, the higher the carbon storage capacity.

Changes in land management practices, away from mixed farming systems towards continuous cropping have further reduced carbon stores. Other contributing factors include summer weed control and chemical fallowing as nutrient conservation and water-use efficiency strategies.

Solutions

• Improve or maintain good soil structure by reducing risks of erosion and compaction;
• Consider perennial pastures or longer growing seasons to improve inputs of organic carbon;
• Stubble retention in cropping only farming systems; and
• Improve plant growth by optimising nutrition and water use efficiency.

Further Reading

Apal Agricultural Laboratory. Undated. Soil Test Interpretation Guide. http://www.apal.com.au/images/uploads/resources/Soil_Test_Interpretation_Guide_1.pdf

Carbon Farmers of Australia. 2017. ‘Carbon Farmers of Australia.’ https://www.carbonfarmersofaustralia.com.au/

Carbon Link. Accessed 26/04/2018. ‘How can soil carbon be increased?’ http://carbonlink.com.au/soil-carbon/how-can-it-be-improved/#

Department of the Environment and Energy (Cth). 2018. ‘Increasing soil carbon under the Emissions Reduction Fund.’ http://www.environment.gov.au/climate-change/government/emissions-reduction-fund/publications/erf-fs-increasing-soil-carbon

Department of Primary Industry and Regional Development (DPIRD). 2018. ‘Carbon farming: applying biochar to increase soil organic carbon.’ https://www.agric.wa.gov.au/soil-carbon/carbon-farming-applying-biochar-increase-soil-organic-carbon

Grains Research and Development Commission (GRDC). 2018. ‘Carbon storage for healthy WA soils.’ https://grdc.com.au/archive/key-issues/carbon-storage-for-healthy-wa-soils/details

Liebe Group. 2017. ‘Improved stubble and soil management practices for sustainable farming systems in the Liebe Area.’ http://liebegroup.org.au/projects-2/past-projects/grdc/

NSW Government. 2010. A Farmer’s guide to increasing soil organic carbon under pastures. https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0014/321422/A-farmers-guide-to-increasing-Soil-Organic-Carbon-under-pastures.pdf

Soils For Life. 2017. ‘Soil – key to landscape regeneration.’ http://www.soilsforlife.org.au/soil.html