Case study:
Marble Hill carbon project
Project details
Marble Hill is a 48-hectare carbon project which began in 2021 and is still on-going.
When the project began, the paddocks were made up of acidic clay soils, and pastures showed symptoms of aluminium toxicity. These paddocks were extremely boggy in wet seasons, and rock-hard in dry seasons.
The soil was treated using 100% recycled products that included lime residuals from water treatment plants in Sydney, which were chosen for their calcium content and ability to raise the soil pH. Agri-ash provided the soil with much-needed Phosphorus and paper crumble was added to introduce organics into the soil.
All the products used have Resource Recovery Exemptions and Orders granted by the Environmental Protection Authority (EPA). SoilRegen was able to obtain these exemptions by conducting field tests that demonstrated these products have bona fide beneficial use when applied to agricultural soils.
The treatments were spread over the topsoil and integrated to a depth of 250mm with a cultiplow.
Results
The pastures have seen almost double the productivity since the soil modifications were implemented. The treatments have increased the soil's pH, soil organic carbon and water-holding capacity, which has not only improved the fertility of the land but also extended the growing season.
No fertilisers were required by the paddocks since the initial treatment was applied to the soil.
The improvements to the soil have had a direct impact on the improvement of the cattle operations at Marble Hill, with the cattle stocking rate more than doubling since 2021.
Performance of treated paddocks in Summer 2025
- Paddock on the left received treatment in May 2025
- Paddock on the right has received no treatment
- Photo taken in November 2025
Photo taken in 2021 before treatment
- By-product stockpiles are visible adjacent to the treatment area
- Previous owner said he had never been able to grow pasture on the scalded area
Long-term performance of treated paddocks in Summer 2025
- Paddock on the left received treatment in 2022
- Paddock on the right has received no treatment
- Photo taken in November 2025
Photo taken in 2024 after treatment
- The treatment was applied to the right side only of the fence only
Measuring grass growth of the untreated test strip
Measuring grass growth of the treated test strip
Test strips showing the benefits of liming treatments
- Different rates of lime residuals treatment were applied to each test strip to help us determine the ideal application rate
- The paces between test strips were untreated
Improved farm operations due to aggregate stability
Our soil treatments have delivered more than just productivity gains, and have changed the operations of the farm.
By improving soil health, our treatments have enhanced the aggregate stability and water-holding capacity of the soil in our paddocks. Paddocks that were once boggy when wet and rock-hard when dry have become reliably trafficable year-round—while also delivering high water infiltration and deeper root penetration.
This photo was taken in an untreated paddock with no major waterways. Tractor is towing a fully loaded spreader with ~18 tonnes of material
This photo was taken in a treated paddock 4 days later. The tractor is towing the same fully loaded spreader carrying ~18 tonnes of product and driving through a major waterway downhill of a dam.
Aggregate stability does NOT mean impenetrable soils
Our treated soils are able to support a fully loaded tractor and spreader whilst also allowing the full depth of our penetrometer (1.2m)
This penetrometer demonstration was taken in the same paddock, on the same day. and along the wheel path of the fully loaded tractor and spreader pictured above.
Photo gallery
