Global assessment ... An Indian farmer checks his crops in a field on the outskirts of New Delhi on November 27, 2011.

Global assessment ... An Indian farmer checks his crops in a field on the outskirts of New Delhi on November 27, 2011. Photo: AFP

The United Nations has completed the first-ever global assessment of the state of the planet's land resources, finding in a report today that a quarter of all farmland is highly degraded and warning the trend must be reversed if the world's growing population is to be fed.

The UN Food and Agriculture Organisation estimates that farmers will have to produce 70 per cent more food by 2050 to meet the needs of the world's expected nine billion-strong population.

That amounts to 1 billion tonnes more wheat, rice and other cereals and 200 million more tons of cow and other livestock

But as it is, most available farmland is already being farmed, and in ways that actually decrease its productivity through practices that lead to soil erosion and wasting of water.

That means that to meet the world's future food needs, a major "sustainable intensification" of agricultural productivity on existing farmland will be necessary, the FAO said in "State of the World's Land and Water Resources for Food and Agriculture".


The report was released today, as delegates from around the world meet in Durban, South Africa, for a two-week UN climate change conference aimed at breaking the deadlock on how to curb emissions of carbon dioxide and other pollutants.
The report found that climate change coupled with poor farming practices had contributed to a decrease in productivity of the world's farmland following the boon years of the Green Revolution, when crop yields soared thanks to new technologies, pesticides and the introduction of high-yield crops.
Thanks to the green revolution, the world's cropland grew by just 12 per cent but food productivity increased by 150 per cent between 1961 and 2009.
But the UN report found that rates of growth have been slowing down in many areas and today are only half of what they were at the peak of the Green Revolution.

It found that 25 per cent of the world's farmland is now "highly degraded", with soil erosion, water degradation and biodiversity loss.

Another eight per cent is moderately degraded, while 36 per cent is stable or slightly degraded and 10 per cent is ranked as "improving".
The rest of the earth's surface is either bare or covered by inland water bodies.