Activated carbon for Soil Health, Crop Yield, and Drought Resilience in South Africa
Activated carbon, a carbon-rich soil amendment made through the pyrolysis of biomass, is gaining attention in South African agriculture as a sustainable solution to enhance soil fertility, improve crop yields, and boost drought resilience. Although still in the early stages of large-scale deployment, both global and local research confirms the significant agronomic and environmental benefits of integrating Activated carbon into crop and forestry systems.
Improved Soil Fertility and Crop Yields
Activated carbon’s high porosity and surface area allow it to absorb and retain nutrients such as nitrogen (ammonium and nitrate), potassium, and phosphorus. These nutrients are slowly released, improving nitrogen use efficiency (NUE) and reducing leaching losses. In the South African context, this means farmers can sustain or even increase yields while reducing fertiliser inputs.
Soil Acidity Correction and pH Optimization
Many South African soils are naturally acidic or have become acidic due to prolonged fertilizer use. Activated carbon’s alkaline pH can help neutralize soil acidity, much like lime.
- Studies from gov.za confirm that Activated carbon applications raise soil pH, reduce aluminium toxicity, and improve root development.
- Its rich mineral content (Ca, Mg, K) improves nutrient availability and supports healthier plant growth on acidic soils.
This makes Activated carbon a valuable addition for farmers in regions such as KwaZulu-Natal, Mpumalanga, and Limpopo, where acidic soils limit crop productivity.
Enhanced Water Retention and Drought Tolerance
One of the most valuable benefits of Activated carbon is its ability to increase soil moisture retention, which is crucial in South Africa’s water-stressed agricultural zones.
- The micro-porous structure of Activated carbon acts like a sponge, storing water during rains and releasing it during dry spells (gov.za).
- Activated carbon improves infiltration, reduces runoff, and lowers soil bulk density, promoting better plant hydration during periods of drought.
According to verra.org, Activated carbon application in semi-arid and arid regions has shown the strongest results, making it ideal for rainfed cereal and horticulture systems under climate stress.
Multiple Soil Health and Climate Benefits
Incorporating Activated carbon or activated carbon into soils delivers a holistic set of improvements:
- Boosts soil organic carbon and microbial activity
- Enhances nutrient cycling and availability
- Improves drought resilience and plant water-use efficiency
- Raises soil pH and combats long-term acidification
These benefits directly contribute to climate-smart agriculture and improved yield stability under extreme weather conditions.
Recognized by Government and Climate Initiatives
The South African Department of Forestry, Fisheries and Environment (dffe.gov.za) recognizes Activated carbon as a key land-based climate mitigation and adaptation tool. Its use is also endorsed in national assessments of carbon sinks, due to its potential to store carbon long-term and enhance land productivity.