Nestlé factory's waste cocoa shells fertilise Norfolk wheat

This novel use of a confectionery by-product is being put to the test at Rookery Farm in Wortham, near Diss.

Cocoa shell pellets supplied by the Nestlé factory in York have been applied to wheat which is being grown alongside crops fed with artifical nitrogen fertiliser - a key plant nutrient, but also a major source of agriculture's greenhouse gas emissions.

The performance of the natural nitrogen source will be compared through yield analysis and grain nutrient sampling after this summer's harvest.

Farm manager Richard Ling with a wheat field fertilised with cocoa shells from a Nestlé chocolate factory (Image: Chris Hill)

Farm manager Richard Ling said collaborations like this are a crucial step towards achieving "net zero" climate goals in the food and farming industries.

"Nestlé have turned their cocoa shell into a fertiliser we can use back in the fields, and it was previously a waste product they were paying to dispose of, so it is a win-win situation. 

"They are looking to support farmers by providing them with low-carbon fertiliser, so they can buy the low-carbon wheat back into their factories like Purina [the firm's pet food subsidiary] at Sudbury and other places around the UK.

"They know if they don't step in and help us achieve net zero, they are not going to get carbon-neutral wheat.

"So we have to be prepared to work together with big companies like this. We want to be able to grow carbon neutral wheat, but I don't know how else we are going to achieve that if we don't start using some of these products to offset our nitrogen - it is our biggest problem."

Cocoa shells from a Nestlé chocolate factory have been used to fertilise a wheat field at Rookery Farm near Diss (Image: Chris Hill)

Of the eight tonnes of cocoa shell pellets produced by the factory, seven tonnes was used at Rookery Farm. 

The natural fertiliser, which contains about 10pc nitrogen, was applied in a single dose on March 26, with no artifical fertiliser added.

The trial was discussed at the farm's final meeting as the Diss Monitor Farm - part of the knowledge-sharing network run by the Agriculture and Horticulture Development Board.