Cullen Wines Wilyabrup soil carbon project

Cullen Wines Wilyabrup soil carbon project is a soil carbon sequestration project located in Wilyabrup, situated in the renowned Margaret River wine region of Western Australia, roughly halfway between the major towns of Busselton and Augusta. Registered in June 2021, the project currently covers an area of 83.75 hectares following an expansion to the project area in February 2023. The surrounding region's land use is predominantly dedicated to premium viticulture, alongside pastoral grazing, agriculture, and tourism.

The project operates under the Estimation of Soil Organic Carbon Sequestration using Measurement and Models Methodology Determination 2021, having formally transitioned from the older 2018 methodology in December 2022. Soil carbon projects of this type involve introducing new agricultural management practices to increase the amount of carbon stored in the soil. Standard activities for this specific project include altering the stocking rate, duration, and intensity of livestock grazing, alongside re-establishing and rejuvenating pasture through seeding and multi-species pasture cropping to promote soil vegetation cover and improve overall soil health.

The Wilyabrup area experiences a coastal Mediterranean climate characterized by high annual rainfall of approximately 1,000 millimeters, with the vast majority falling during mild, wet winters. The local soils predominantly consist of well-drained gravelly sands, lateritic profiles (such as Forest Grove types), and sandy loams situated over granite and gneiss. These low water-retention soils, combined with the coastal breezes from the Indian Ocean, are highly prized for cabernet sauvignon and chardonnay grape cultivation.

Cullen Wines, a historic and certified biodynamic winery, initiated this project after an in-house sampling program revealed that their sustainable practices were already resulting in a steady natural increase in soil organic carbon. Partnering with the agricultural carbon consultancy Carbon West, the winery formalized these efforts into a registered ACCU project. To build soil carbon, the project involves sowing mid-autumn and late-spring multi-species cover crops of up to 12 different species, incorporating native seeds when practicable. These crops are then crimped or used for high-density, short-duration grazing to build biological activity. In early 2022, the initiative was further supported by a $36,000 grant from the Western Australian Government's Carbon Farming and Land Restoration Program, helping Cullen Wines offset their future emissions and continue their commitment to regenerative agriculture.