Carbon levels in soil have come under the spotlight in new research | Video

VALUABLE RESEARCH: Dr Susan Orgill of NSW Department of Primary Industries has completed work about carbon levels in soil. Picture: Nikki Reynolds
VALUABLE RESEARCH: Dr Susan Orgill of NSW Department of Primary Industries has completed work about carbon levels in soil. Picture: Nikki Reynolds

WORLD Soil Day is a wonderful time to celebrate soil health, practitioners, farmers and advisers says Susan Orgill of NSW Department of Primary Industries.

Dr Orgill recently completed research into carbon uptake in soil and said the work coincided well with the upcoming international day on December 5. 

World Soil Day celebrates the importance of soil as a critical component of the natural system and as a vital contributor to the human commonwealth through its contribution to food, water and energy security and as a mitigator of biodiversity loss and climate change.

It is celebrated particularly by the global community of 60,000 soil scientists charged with the responsibility of generating and communicating soil knowledge for the common good.

“My research looked at the farm management practices to increase soil carbon in grazing systems,” Dr Orgill said. And sequestering carbon in soil has been identified as a strategy to mitigate climate change.

It was these topics which featured in Dr Orgill’s PhD research. 

A member of the Graham Centre for Agricultural Innovation, Dr Orgill will be awarded her PhD during a graduation ceremony at Charles Sturt University (CSU) on Tuesday, December, 12.

“My research demonstrated that the ability of soil to sequester carbon has no upper limit, however the carbon storage potential is driven by regional climate and soil properties more than farming practice,” Dr Orgill said.

“Within a given region, fertiliser management has a greater potential to influence carbon sequestration than grazing management.

“Farmers can use my research to prioritise efforts and inputs to increase soil carbon. Nutrients are required by both plants and microbes to increase soil carbon, and some soils are just inherently better at accumulating carbon than others.”

Dr Orgill completed her PhD while working full-time for the and NSW DPI and with two young children.

As NSW DPI  soils leader, she’s working to develop management strategies to increase carbon in agricultural soils and overcoming soil constraints to pasture production.

“I’m passionate about working with producers and advisers to increase the productivity and profitability of agricultural systems through smart soil management,” Dr Orgill said.


  • Soil is the network of interacting living organisms within the earth's surface layer which support life above ground.
  • The nutritional value of the food we eat is directly related to the health of the soil in which it grows (or what it eat grows).
  • Management of agricultural soils should consider the structural, biological and mineral health of the soil (not just N, P, K) to produce nutritionally-dense food.
  • Soil has varying amounts of organic matter (living and dead organisms), minerals, and nutrients.
  • An average soil sample is 45% minerals, 25%, 25% air, and 5% organic matter (less in degraded soils).
  • Carbon is a master variable within the soil that controls many processes, such as development of soil structure, water storage and nutrient cycling.
  • On average, Australia’s current soil organic carbon content is only around 1%. 
  • In the 1800s, some of the most productive farms in south eastern Australia recorded soil organic carbon content of nearly 20%.
  • Soil high in organic carbon content enables better rainfall infiltration and retention – providing greater resilience to drought.