Weelhamby Farm Soil Improvement Project

Weelhamby Farm Soil Improvement Project is a soil carbon sequestration project located near Perenjori, approximately 185 kilometres east-south-east of Geraldton on the eastern edge of the Western Australian Wheatbelt. It was registered in December 2021 and covers a total project area of 5,258.24 hectares, though an August 2025 variation removed some specific areas from the project.

The Estimation of Soil Organic Carbon Sequestration using Measurement and Models (2021) methodology involves changing agricultural management practices to increase the amount of carbon stored in the soil. Standard requirements for this project type include undertaking new or materially different management activities and conducting regular soil sampling to physically measure the increase in soil organic carbon against a historical baseline.

The Perenjori region is located in a semi-arid, low-rainfall zone that typically receives less than 300mm of rain annually. Land use in this North Midlands area has traditionally focused on broadacre cereal cropping and livestock grazing, with regional soils largely consisting of red sandy loams, clays, and gravelly loams.

This project aims to demonstrate the viability of building soil carbon in a marginal farming area without locking up productive agricultural land. The project activities focus on rejuvenating pastures by shifting from high-input cereal cropping to a grazing enterprise with a three-year pasture and one-year crop rotation. Establishing multi-species pastures with legumes aims to protect topsoil, increase soil water-holding capacity, and build organic carbon levels from 0.7% to 1.2% in the top 30cm over the first ten years.

Notably, Weelhamby Farm, co-owned by project manager David Martin, received over $738,000 in funding through the WA Government's Carbon Farming and Land Restoration Program. The soil carbon initiative is closely integrated with the property's separate 230-hectare biodiversity revegetation project, which is establishing wildlife corridors. Furthermore, the farm collaborated with Edith Cowan University on the Transformative Aboriginal Agricultural Methods (TAAM) project, trialling traditional Maaman Marra Boodjar land management practices, such as using leaky weirs, to slow water movement, rehydrate the landscape, and build long-term drought resilience.