We think of it as inert fragments of sand and clay, but they are just the start. Around them over the centuries builds up a rich web of life, from earthworms to micro-organisms, fungi to bacteria; and all the various elements in the web play their part in breaking down the waste of Some species provide nutrients to others in a dynamic interactions reaching out to many parts of the web. Cultivations with just the basis nitrogen/phosphorus/ potash fertilisers gives a short-term boost but depletes the soil over time, as essential minerals get used up in seasonal plant growth, and for long-term healthy soil the trace substances need to be replenished. Composting is one way to do it, with the further great advantage of using up food and garden waste, and good compost is carefully balanced. It’s been found that the take-up of nutrients from the compost is helped by adding waste minerals to the land, for instance from filtrates from the water industry.