World farm production must rise 60 percent by 2050 to meet the needs of a growing population but this has to happen in "a more sustainable way," the UN food agency FAO and the OECD said on Wednesday.
"It's mostly going to be about productivity," Angel Gurria, head of the Organisation for Economic Cooperation and Development (OECD), said at a press conference in Rome, explaining that farmland area would increase only slightly.
"It's a pretty tough challenge because the endowment of resources is limited and we haven't been very wise," he said, adding that around a quarter of land currently being farmed is considered "highly degraded" because of overuse.
Food and Agriculture Organisation (FAO) head Jose Graziano da Silva said the world had to pursue new and more sustainable ways to increase production.
"We cannot increase production with the same model as in the past. We must increase productivity in a sustainable way, particularly in developing countries and among small-scale farmers," Graziano told reporters.
The two organisations said growth in production will come mainly from developing countries but would be less vigorous than in recent years.
"The increase in production has happened primarily in developing countries. It has been led by Latin America and the Caribbean and sub-Saharan africa -- the two regions with the greater agriculture potential today," he said.
World farm production has grown at 2.0 percent a year in recent decades but the rate is expected to slow to 1.7 percent a year, the joint report said.
Despite the slowdown, the rate is to exceed expected demographic growth, meaning that farm output per inhabitant will grow by 0.7 percent a year.
The calculations in the FAO-OECD report do not however take into account the rapid growth in the biofuels sector, with experts estimating that world production of bioethanol and biodiesel will nearly double by 2021.
Graziano also pointed out that FAO's food price index has been falling for the past three months and in June was 12 percent lower than in June 2001.
"But we are still seeing volatility. The preliminary data has shown that the food price index may rise again in the next few months," he said.
"Over the next 10 years we expect food prices to decline or remain stable from current levels. However, on average, they will still be between 10 and 30 percent higher than the previous decade," he added.