• Swindon & Wiltshire Innovation
• Wednesday April 15 2026

Bristol wee-based fertiliser to help grow trees in Wales

A unique urine-based fertiliser developed by scientists in Bristol will help grow 4,500 threatened British trees in Wales.

Bristol-based sustainable science startup NPK Recovery transforms urine into a safe and effective fertiliser during events like Boomtown Festival and the London Marathon.

Now, the fertiliser – which doesn’t smell – will be used to grow 4,500 native trees like beech, in a project backed by a £435,000 grant from the Forestry Commission.

A Scots pine seed was planted earlier this month in the Brecon Beacons National Park, marking the start of the three-year project.

It was planted at a nursery run by NPK Recovery’s project partner, Stump up for Trees’, a charity boosting tree diversity around the national park.

It comes as fertiliser prices have soared due to the Iran war, leaving farmers struggling to make ends meet and sparking fears that the cost of food could rise.

Multiple studies have shown that NPK Recovery’s fertiliser is just as effective as commonly used alternatives, which are typically made abroad using energy-intensive processes. This is the first time their fertiliser has been trialled on trees.

NPK Recovery co-founder Lucy Bell-Reeves (pictured) said: “Using a waste product to grow trees is a circular solution that can revitalise our struggling native species.

“We need to stop flushing crop and tree-growing nutrients down the loo, and start using them to increase our fertiliser security. After all, we’re not about to run out of urine any time soon.

“I love the idea that by the end of this three-year project, revellers and runners will have created a fledgling Welsh forest, which could flourish for hundreds of years.”

NPK Recovery takes its mobile laboratories to events across the country, transforming the nitrogen and other nutrients in event-goers’ wee into fertiliser as the event runs. Processing it at source eases the burden on sewage systems and reduces chemical use.

The fertiliser can then be used to revitalise the event site and grow crops and trees in the surrounding fields.

The project was made possible by a £435,627 Forestry Commission grant awarded via the Tree Production Innovation Fund.