Soya is a subtropical crop largely grown in Brazil, Argentina and the US. The UK imports £1bn worth of soya each year, 95 per cent of which goes to animal feed for chickens, sheep, pigs, cattle and farmed fish. It's also an essential ingredient in a wide range of things from bread to ice cream.
New varieties of soya can cope with the cooler, less sunny climate in England. In the past year there has been a fivefold increase in the area planted in the southern half of England, with about 4,500 acres this year.
The world price for soya has soared as growing demand for meat in China has pushed up the cost of livestock feed. Soya now sells for about £400 a tonne, compared with about £140 for wheat and £330 for oil seed rape.
It also cheaper to grow than traditional crops because it does not suffer much from pests and diseases, a key consideration when plant protection products are becoming less readily available. It fixes nitrogen from the atmosphere in its roots and can help to break up blackgrass, a growing weed problem in cereal fields. This makes soya a valuable break crop in spring rotations to help to kill off diseases, pests and weeds in the ground.