A low-carbon fertiliser made from a chocolate factory's waste cocoa shells has been successfully trialled on a Norfolk farm.

Food firms Nestlé and Cargill are collaborating on the project, which was put to the test at Rookery Farm in Wortham, near Diss - one of two trial farms supplying wheat to Nestlé factories making breakfast cereals and Purina pet food.

The cocoa shells are supplied by Cargill, which processes cocoa in York as a key ingredients in the manufacture of chocolate bars such as KitKat and Aero. A trial volume of cocoa shell was processed and pelletised by Swindon-based CCm Technologies.

The two-year farm trial aims to evaluate the fertiliser’s performance on crop production, soil health and greenhouse gas (GHG) emissions, compared to conventional chemicals applied on the same farm.

If successful, up to 7,000 tonnes of low-carbon fertiliser pellets could be produced for farmers in Nestlé’s UK supply chain - around 25pc of the firm's total fertiliser use for wheat.

Richard Ling, farm manager at Rookery Farm, has now finished harvesting his first wheat crop grown with the confectionery by-product - and he was impressed with the results.

"We’ve compared two parts of the field, one which used the cocoa shell fertiliser, and one which used with the conventional fertiliser, and there is no significant difference in the yield so we can see that it works," he said.

“We are really reassured with the results and are looking at running further trials.

"It’s a step change to be able to use a fertiliser made from a waste stream and see the same results as using a conventional product.

"It’s an exciting and promising time and we are pleased to be taking part in these trials to help reduce the carbon emissions from our farming.” 

The project is part of Nestlé's drive to achieve "net zero" emissions by 2050, and the company has also committed to sourcing 50pc of its key ingredients from regenerative agricultural methods by 2030.

Matt Ryan, regeneration lead at Nestlé' UK & Ireland, said: "We have to find ways to build more resilience into the system and optimising our use of natural resources is a critical part of this.

“This project is a small, but very meaningful step towards a net zero future, where farmers, local enterprises, and nature all stand to benefit."