that's a mix of fibs (rise not that much) and land being seen as investment beating interest rates return or inflation.
When Queen Elizabeth II acceded to the throne in 1952 at the age of 25 farmland values stood at £78 per acre, equivalent to £1,700 per acre in real terms . Now, 70 years on, the average value in England is £7,800 per acre.
If land values had only risen to £1700 acre genuine Farmers would be better off. Return on capital quoted at 2% with land at £10k acre would be 12% enabling farmers to expand and buy land. I believe the only Farmers who can afford to buy land are the ones who have sold land for housing.