Amid world pressure from heatwaves and fertiliser shortages, billionaire’s business has invested in circular farming and biomethane

There is a distinctive smell of cow manure in the air at the Duke of Westminster’s dairy farm near Chester. It is a world away from the collection of grand West End properties controlled by the duke that form the backbone of his near £10bn fortune, a decade on from becoming Britain’s youngest billionaire.

As part of his 349-year-old Grosvenor empire, Lea Manor Farm on the duke’s Eaton Estate in north-west England has fared better than most dairy farms in recent years.