Rice farmers could boost their yields by 50 percent with a new method that uses less water Oxfam America said as climate change and drought threaten the staple crop.

Growing rice -- considered the major calorie source for about half the world's population -- is water-intensive, accounting for as much as one-third of the planet's annual freshwater use, said Oxfam, a development group.   

Rice farmers normally rely on flooding their fields to keep seeds covered in water throughout the growing season. But the new method, known as the System of Rice Intensification, or SRI, involves planting seedlings farther apart, keeping fields moist instead of flooding them, transplanting seedlings to fields earlier and weeding manually, Oxfam said in a report.

Farmers using SRI in parts of Africa, Southeast Asia and India have been able to produce as much as 50 percent more rice with less water, and often with less labour, said the report, written with US-based nonprofit Africare and the Worldwide Fund for Nature.

Oxfam's goal is to encourage rice-producing countries to convert 25 percent of rice cultivation to SRI by 2025. "Practices like SRI can both easily translate to increased production and income for farmers," Oxfam president Ray Offenheiser said on Wednesday at an event in Washington.   

"The benefits have been tangible, improving livelihoods," he said. Drought is a top concern for rice producers like Vietnam, where a water shortage this year could hurt production in a key area accounting for 90 percent of the nation's rice exports.

A new study from the US National Center for Atmospheric Research said the world's most populous areas could face severe droughts in the next few decades.   

The group wants governments in developing countries to adopt SRI in national development strategies and hopes aid agencies invest in training farmers to use the method.   

Duddeda Sugunavva, a farmer from the Andhra Pradesh state in southeastern India, said it took her a couple of seasons to get used to the new method after she learned about it from an aid group. 

But she told the audience on Wednesday that she harvests about 50 percent more rice per acre using the system. "The population is increasing, but the land is not increasing," she said at the Oxfam event. "I want all women farmers to come forward and do SRI." - Reuters