A global rice shortage looms unless more grain can be produced from a shrinking acreage of paddy fields.

The world needs a new boost to rice yields, similar to the “Green Revolution” of the 1970s (when yield was improved by the use of “miracle seeds”), if we are to feed the growing population that depends on rice for survival, according to Robert Ziegler, head of the International Rice Research Institute in Manila.

Half the world’s population depends on rice, but stocks are at their lowest level since the mid1970s. Meanwhile, demand for rice continues to increase as the world’s population expands and urbanisation erodes farmland.

Mr Ziegler said: “We are facing a problem and it is the poor that are going to be hit most severely.”

Rice production will this year fall to just below the consumption of 430 million tonnes.

New high-yielding grain varieties and crop management techniques provided a huge boost to global food output in the 1970s and researchers believe that the world needs another such transformation.

The forecasts coincide with a warning from the UN’s Food and Agricultural Organisation (FAO) that the surge in grain prices is beginning to hurt vulnerable people in developing countries. The FAO’s Global Information and Early Warning System signalled last week that price rises in staples, such as bread, pasta and tortillas, were fuelling unrest.

The FAO said: “In the past months, food riots have broken out in Mexico, Morocco, Uzbekistan, Yemen, Guinea, Mauritania and Senegal.”

In Britain, consumers have noticed the impact of the global grain shortage on prices. However, for developing countries that struggle to meet food import bills, such price increases can be damaging to populations that spend 80 per cent of their income on food.

Wheat prices have risen by more than 50 per cent over the past year and the FAO said that if production does not rise significantly next year, “higher prices will lead to deterioration of diets”.

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