GENEVA -- The world urgently needs to adopt drought-management policies as farmers from Africa to India struggle with lack of rainfall and the United States endures the worst drought it has experienced in decades, top officials with the UN weather agency said Tuesday.

The World Meteorological Organization says the U.S. drought and its ripple effects on global food markets show the need for policies with more water conservation and less consumption. It is summoning ministers and other high-level officials to a March meeting in Geneva where it will call for systematic measures toward less water consumption and more conservation.

U.S. farmers have experienced one of their worst growing seasons in memory. The annual corn harvest, for example, is much farther along than it ordinarily would be and expected to produce the least amount of corn since 2006 -- despite the most acres of corn planted in more than 70 years -- due to unusual triple-digit summer temperatures that disrupted pollination and a severe drought particularly in the middle of the country.

"Climate change is projected to increase the frequency, intensity, and duration of droughts, with impacts on many sectors, in particular food, water, health and energy," WMO Secretary-General Michel Jarraud said. "We need to move away from a piecemeal, crisis-driven approach and develop integrated risk-based national drought policies."

Mannava V.K. Sivakumar, director of WMO's climate prediction and adaptation branch, says only Australia has a national policy toward drought and the advantage of a policy -- rather than a disaster management, which some countries have -- is that national action is required no matter who is in political power.

Australia's government says its 2004 policy is no longer sufficient to deal with climate change, however, and over the past two years it has tried a pilot program in western parts of the country aimed at shifting from a crisis-oriented approach to risk management.

Sivakumar said the agency is also encouraging more continuing support especially for "the poorest of the poor," small farmers whose daily wages determine whether they and their families will eat on any given day.

Another idea whose time has come, he said, is so-called water harvesting, which is the collection of surface runoff. It is the precipitation often lost among farming regions in semi-arid places with irregular rainfall that can't afford expensive irrigation systems. It also causes soil erosion, but if the rainfall is collected it can be stored for later use.

"Those are the sort of people that need to be addressed," Sivakumar told reporters in Geneva. "One of the major issues is coordination."

The WMO says severe drought developed in parts of East Africa in late 2010 and continued through most of last year, with the worst-affected areas the semi-arid regions of eastern and northern Kenya, western Somalia and some southern border areas of Ethiopia. Elsewhere, it says, the most significant drought of 2011 was in south-central U.S. states and bordering areas of northern Mexico.

In India, there has been insufficient rainfall in half of the country's 624 districts despite the monsoon season that began in early June, and total average seasonal rainfall starting then through August 1 came in below the 90 percent average that is the cut-off line for defining drought.

U.S. officials say about two-thirds of the contiguous United States has been suffering from moderate to exceptional drought this summer, with the extreme dryness and excessive heat killing crops and livestock from the Great Plains to the Midwest.

The U.S. drought monitoring map that produced the figures, WMO officials say, is an example of a tool that most other countries should have but don't.