Plantwatch: phosphate leading to widespread pollution

Phosphate fertilisers are causing dangerous levels of pollution in waterways that harm aquatic plants and animals

Much of the environment is awash with fertilisers, boosting thuggish weeds such as stinging nettles that swamp other wild plants. Nitrate is a big villain in this onslaught, but far less notice is taken of phosphate.

Phosphate is crucial for plant growth and development, and it is estimated that half the world's food supplies rely on phosphate fertilisers, but this is a dwindling resource that is used very inefficiently, which is leading to widespread pollution. Unlike nitrate, phosphate binds very strongly to the soil, which makes it difficult for plant roots to get hold of. And so farmers apply even more phosphates in fertilisers and manure, although much of that phosphate then sticks to the soil again, driving the levels of phosphate in the soil even higher.

Related: Conservationists claim 'legal victory' in dispute over government protection of rivers