Transforming Farm Waste into Carbon-Locking Biochar with Re-generation Earth
- Growing Kent & Medway
- Jan 8
- 4 min read
Updated: 5 days ago
Re-generation Earth, in collaboration with the University of Kent, utilised one of our large R&D grant programmes to establish an on-farm "Living Lab" for biochar production. The project demonstrated that while biochar is most effective as a nutrient carrier rather than a standalone fertiliser, it offers significant potential for long-term carbon sequestration and soil health improvement.
At A Glance: Project Quick Facts
Project Lead: Re-generation Earth (Richard Bowe)
Collaborator: University of Kent (Dr Anastasios Tsaousis)
Total Funding: £427,802 (Grant Awarded: £215,553 / Co-investment: £212,249)
Key Finding: Biochar serves as an excellent "carrier" for nutrients when combined with materials such as manures, composts, and insect frass, significantly improving microbial diversity.
Food System Areas:
The Challenge: Scaling Soil Health Solutions
For Richard Bowe, founder of Re-generation Earth, the inspiration came from observing the land itself. "As a farmer, I understand that where we've had hedgerows and burnt them, the soil improved in that area," Richard explains. Farmers have long known that burning plant waste, such as trimmings from overgrown hedges, produces charcoal. This charcoal improves fertility by its sponge-like structure, which helps retain water and nutrients in the soil.
However, farmers cannot simply burn waste across the countryside; open burning can be risky, damaging to the immediate environment, and releases vast amounts of carbon dioxide directly into the atmosphere. Richard needed a scalable, innovative way to replicate these benefits without the risk and environmental cost.
The Innovative Idea: On-Farm Biochar Production
The solution was biochar. Unlike charcoal, biochar is produced in a cleaner, more controlled way specifically for agricultural use. It retains the honeycomb-like structure of the original woody waste, acting like a rigid sponge. This structure allows it to absorb water and nutrients, preventing them from leaching and keeping them locked in the soil until crops need them.
To produce biochar sustainably, the project used an on-farm "retort" – essentially a sealed industrial oven. This technology heats plant waste in a low-oxygen environment (pyrolysis). Because there is no oxygen, the material doesn't burn to ash; instead, it bakes into biochar, locking the carbon into a solid form for centuries rather than releasing it into the atmosphere as carbon dioxide.
The Approach: A 'Living Lab' for Regenerative Farming
Supported by one of our large R&D grant programmes, Re-generation Earth partnered with the University of Kent to install a biochar retort and conduct rigorous field trials. The team tested the application of biochar alone and in combination with other materials. Notably, they collaborated with fellow Growing Kent & Medway grantee Inspro, who supplied "insect frass" (nutrient-rich insect manure) to test as a bioactive additive.
The goal was to test biochar’s ability to support "microbial diversity" – the range of beneficial bacteria and fungi that live in healthy soil. Simultaneously, researchers at the University of Kent conducted a Life Cycle Analysis (LCA) to assess the project's carbon footprint. At the same time, the operational team monitored "flue gases" (chimney emissions) to improve the efficiency of the retort.
The Results: A Nutrient 'Battery'
The trials provided a crucial insight for growers: biochar is not an effective fertiliser by itself. In fact, the project found that applying "raw" biochar can initially reduce crop growth, as its sponge-like structure absorbs existing soil nutrients, effectively hiding them from plants.
However, the actual value was unlocked when the biochar was "charged" before application. By blending it with the insect frass, the biochar soaked up the nutrients first, turning it into a slow-release battery for crops. This combination significantly increased the number and diversity of beneficial microbes in the soil, demonstrating that biochar is best used as a carrier for other nutrients rather than as a standalone product.
See it Differently: Biochar Explained
Looking Forward: Cleaning Waterways to Feed Soil
Re-generation Earth is now looking to apply this "sponge" property to a wider environmental challenge: river pollution. The company is exploring a circular model where biochar is placed in waterways to filter out excess nitrates and phosphates from agricultural runoff and sewage.
Rather than letting these nutrients pollute the water, the biochar would absorb them. Once saturated, the "charged" biochar could be removed and returned to the farm as a potent, free fertiliser. This approach would allow farmers to take custody of their local water quality, turning a pollution problem into a regenerative farming solution.
However, for this innovative market to mature, Richard emphasises the urgent need for standardisation: "The biochar industry desperately needs regulation, as not all biochar is created equal. We need transparency regarding quality, carbon footprint, and porosity, as well as the specific temperatures and equipment used in the pyrolysis process."
Our Support: Driving Progress
This project was supported by one of our large R&D grant programmes, which enabled the purchase of the retort and the vital academic partnership with the University of Kent. This funding was instrumental in moving the concept from a theoretical idea to a physical reality on the farm.
Richard highlighted the impact of this support: "Growing Kent & Medway, along with the University of Kent, have been absolutely brilliant. The team there has really helped us progress and driven us forward."
