Weelhamby Farm Soil Improvement Project

Weelhamby Farm Soil Improvement Project is a soil carbon project located near Perenjori, approximately four hours north of Perth in the Mid West region of Western Australia. It was registered in December 2021 and initially covered 5,258.24 ha, though a variation in August 2025 removed certain areas from the project boundaries.

Soil carbon projects operating under the Estimation of Soil Organic Carbon Sequestration using Measurement and Models methodology involve modifying historical land management practices to increase the amount of carbon stored within the agricultural soil. The standard requirements involve establishing a baseline of existing soil carbon through physical sampling and laboratory testing, implementing eligible new agricultural activities, and undertaking subsequent testing rounds to verify the carbon increases over time. At Weelhamby, this is being achieved by transitioning from high-input continuous cereal cropping to a three-year pasture and one-year crop rotation. The proponent relies on re-establishing or rejuvenating multi-species pastures via seeding or pasture cropping, which are then pulse-grazed by Merino sheep.

The broader Perenjori area is a traditional broadacre agricultural zone situated on the eastern edge of the WA Wheatbelt. The region is predominantly used for dryland winter cropping, such as wheat, barley, canola, and lupins, alongside sheep grazing operations. Environmentally, the area is classified as a low-rainfall, semi-arid zone experiencing a warm Mediterranean climate with sub-300mm annual rainfall. The local soils, which frequently feature acid sandplains, naturally possess very low clay content and low inherent soil organic matter.

An interesting note about this project is that it operates in tandem with the neighboring Weelhamby Farm Biodiversity Project to demonstrate that carbon farming is both financially and ecologically viable in marginal, low-rainfall farming areas without locking up productive agricultural land. Backed by the WA Government's Carbon Farming and Land Restoration Program and supported by project agent Carbon West Pty Ltd, the ambitious project aims to increase topsoil organic carbon levels from a baseline of just 0.7% to 1.2% in the top 30cm over its first decade.