AgZero2030 explores soil organic carbon levels in WA
AgZero2030 explores soil organic carbon levels in WA
By SHANNON BEATTIE
A recent study conducted by AgZero2030 and funded by Landcare Australia has provided insights into soil organic carbon (SOC) levels and soil health across Western Australia's agricultural landscape.
The project, involving farmers from AgZero2030, the Corrigin Farm Improvement Group, and the West Midlands Group, consisted of two main components which shed light on historical trends and future opportunities for farmers in the region.
AgZero2030 secretary Cindy Stevens highlighted the importance of understanding SOC levels for farm productivity, sustainability, and resilience.
“Soil organic carbon is a crucial component of farm ecosystems, influencing everything from crop yields to farm and environmental sustainability,” Ms Stevens said.
- Soil organic carbon concentration in the top 10cm of the agricultural areas of Western Australia. Areas of low confidence are white, grey areas are native vegetation and reserves (DPIRD, 2013).
The first part of the project focused on analysing historical trends in SOC under total cropping and mixed enterprise farms in the Corrigin and Bruce Rock district over a 25-year period.
A gradual downward trend across 25 years of between 0.1-0.4 per cent of SOC losses was observed in total cropping farms.
Mixed enterprise farms displayed more variability in SOC levels of up to 1pc on individual farms and 1.5pc across farms, yet still exhibited a similar downward trend overall.
“It was worth noting that half of the individual farmers in mixed enterprise farms showed an upward trend in their SOC levels, indicating the potential to build SOC levels under mixed farming practices,” Ms Stevens said.
“The real challenge is building, and then maintaining soil carbon, as it is heavily influenced by seasonal conditions and WA’s typically sandy soils, and this becomes more challenging in a drying and warming climate.”
The second part of the study focused on assessing SOC levels and soil health under various farm management practices sampled and tested across the WA agricultural region in 2023, from Badgingarra to Gnowangerup.
The results demonstrated that most remnant vegetation sites had the highest SOC levels and soil health scores.
These results could aid farmers in setting realistic target SOC levels specific to their farm and soil types when planning to increase SOC levels.
- Soil sampling amongst remnant vegetation.
The study also identified farm management practices that can enhance SOC levels and soil health.
“Improved pastures, legume-based or perennial, along with soil amelioration practices such as mould board ploughing and liming, were found to increase SOC levels compared to traditional methods,” Ms Stevens said.
The study suggested farmers would benefit from testing SOC levels consistently and at precise locations to obtain baseline levels to be tracked over time, in order to effectively monitor the impacts of their farming practices on SOC.
This data will help inform sustainable and profitable management strategies and may allow farmers to capitalise on future market opportunities in banking and markets with sustainable or low carbon products.
“Soil carbon projects and practices that promote SOC permanence not only benefit farm productivity but also contribute to broader sustainability goals," Ms Stevens said.
As AgZero2030 continues to work on climate literacy and the energy transition in the agricultural industry, it hopes farmers can make informed decisions when it comes to carbon projects and farming for business and climate resilience.