More than 96 per cent of all the food grown in Britain is reliant on synthetic fertiliser. Without it there would be serious trouble.

But without artificial fertiliser there's not enough nutrients for the crops to grow, and without ploughing there is nothing to aerate the soil. So how can we manage without them?

The answers are in nature. As Charles Darwin pointed out, earthworms have been ploughing and aerating the soil for millions of years. And as for fertilisers, just look at how a forest flourishes: by using the natural fertility created by billions of living microbes, fungi, plants and animals.

The non-destructive, low-energy methods are elements of a wider system known as Permaculture, which challenges all the normal approaches to farming. One of its central principles is that you work with the land, rather than against it.