And dumping nutrients such as iron into the sea would be only one-sixth as effective as either sulphate injection or promoting the formation of clouds.

ECONOMIST: Geo-engineering

For decades, discharges by wastewater treatment plants and land runoff have led to excessive levels of nutrients such as nitrogen and phosphorus in Long Island Sound.

WSJ: Connecticut Seaweed: Life Down on the Kelp Farm

If a person receives too much or too little fluid this can lead to problems such as fluid in the lungs, dangerously raised or lowered levels of potassium, sodium or nutrients such as glucose, and in some cases, heart failure.

BBC: drip bag

Levels of key nutrients, such as phosphate and nitrate, are highest in the Midlands, East and South of the country where population density is highest and farming methods the most intense.

BBC: English and Welsh rivers 'improving'

While crushing pills may ensure that they break down appropriately in the stomach, taking them with milk is not great idea, as milk may interfere with the absorption of some of the nutrients in a multivitamin such as iron.

CNN: Are vitamins and supplements effectively absorbed?

As bank lending returns, and if soya prices fall, farmers will switch to crops such as maize, which offer lower returns but return nutrients to the soil.

ECONOMIST: Pros and cons of the soya boom

Organic mulches such as wood chips, pine straw or bark have the added benefit of slowly breaking down which adds nutrients to the soil.

CNN: X-rated yards save the environment