A Tanzanian-developed fertiliser made from crushed volcanic rocks is being promoted as an alternative input to help farmers restore soil fertility, improve crop growth and sustain agricultural production.
The product, branded Volca Grow, is developed by McDonald Horticulture and Soil Specialist Ltd, which says the technology could help address soil degradation through the use of mineral-based inputs that support agroecological farming and environmental conservation.
The company's Marketing Manager, Naima Donald Mwakamele, said the fertiliser is produced by grinding volcanic rocks into fine powder before blending them with other nutrients to create a product that can be mixed with water and applied to different crops.
Speaking at the Hortilogistical Africa 2026 exhibition in Arusha, she said the product works by supporting root development, enabling plants to absorb nutrients more effectively and distribute them to different parts of the plant.
She said its calcium content also helps strengthen plant stems and regulate soil acidity, creating conditions that support healthier crop development.
The fertiliser can be used on a range of crops, including coffee, cloves, flowers and vegetables, while its soil-improvement benefits can last for up to four years, according to the company.
For farmers, the technology could offer an additional option for improving soil health and maintaining productivity, particularly in areas where declining soil fertility threatens agricultural output.
Ms Mwakamele said the idea behind the product emerged from experiments conducted several years ago in Namibia's Kalahari Desert, where the company tested the use of crushed rocks under challenging farming conditions.
The trials successfully supported tomato production, prompting the company to develop the technology further and explore opportunities to introduce it to Tanzanian farmers.
The company is now seeking to expand its operations beyond Songwe and Mbeya regions to other parts of Tanzania and the wider African market.
Ms Mwakamele identified coffee farmers in Kilimanjaro and grape growers in Dodoma as among the potential beneficiaries, saying the product could help improve soil conditions for crops that are important to local agricultural economies.
Meanwhile, Paul Chilewa of the Tanzania Organic Agriculture Movement (TOAM), an umbrella organisation promoting organic and agroecological agriculture, said environmentally friendly agricultural inputs were essential in protecting soil fertility and supporting sustainable food production.
He said their use also mattered in safeguarding the health of farmers and consumers while reducing the negative environmental effects associated with unsustainable farming practices.
Mr Chilewa said the Ministry of Agriculture's National Ecological Organic Agriculture Strategy recognises the importance of making environmentally friendly agricultural inputs accessible to farmers.
He called for continued promotion of innovations that improve soil health and increase productivity, saying sustainable agriculture depends on farming systems that protect natural resources while supporting farmers' livelihoods.