The 12th annual Deloitte & Touche food and agriculture group survey of farm incomes says the net farm income for the average lowland farming client has risen from £5 to £18 a acre. However, D&T predicts that average profit will fall back to £12 a acre next year, which is still below the five-year average of £23.

Based on these returns, even a well-structured farm is generating significantly less than is needed for expansion.

D&T's partner responsible for food and agriculture, Mark Hill, told the Journal: 'A significant number of our clients have got out of potatoes, and they're not small scale growers either. But they've got to a stage where to be in potato farming your balance sheet needs to be able to take swings of £1m.' Hill added: 'Our figures show that this year 50 per cent of output was generated from food production and the majority of farmers earned nothing from it.' However, he said that despite the 4.4 per cent rise in the minimum agricultural wage, actual labour costs had fallen by 3.6 per cent. Despite this, D&T insists that 'many individual businesses are doing well despite low commodity prices and rising input costs.'