Humphreys Carbon Project 3

Humphreys Carbon Project 3 is a soil carbon sequestration project located in the Shire of Wongan-Ballidu in Western Australia. The project area covers approximately 368 hectares and is situated roughly 7km east of the small locality of Cadoux and about 50km northeast of the regional center of Wongan Hills. It was registered on June 18, 2025.

The project operates under the 2021 Soil Carbon methodology (Estimation of Soil Organic Carbon Sequestration using Measurement and Models). This method enables landholders to earn Australian Carbon Credit Units (ACCUs) by adopting new land management practices that increase the amount of carbon stored in the soil. The specific activity for this project involves applying synthetic or non-synthetic fertilizers to address material nutrient deficiencies, a practice designed to boost plant growth and subsequently increase soil organic carbon levels. The method employs a hybrid approach, using initial physical soil sampling to establish a baseline and computational models to estimate carbon sequestration over the 25-year crediting period.

The surrounding Wongan-Ballidu region is part of the Western Australian Wheatbelt, an area heavily utilized for broadacre cropping and sheep grazing. The local environment is characterized by a "Dry Warm Mediterranean" climate, with hot, dry summers and mild, wet winters, receiving an annual average rainfall of approximately 380mm. The soils in this district are typically a complex mosaic, ranging from deep yellow sands and ironstone gravels to heavier red loams and duplex soils, which often require careful nutrient management to maintain productivity.