Climate change will bringing higher temperatures and more frequent droughts, reducing water availability especially in water-scarce regions, while melting glaciers will eventually cut water supplies in major producing areas, the Food and Agriculture Organization (FAO) said on June 9.

"Both the livelihoods of rural communities as well as the food security of city populations are at risk," FAO Assistant Director General for Natural Resources Alexander Mueller said in a statement.

Countries should improve management of their water resources ahead of the expected changes, and farmers should adopt more efficient cropping patters, the FAO said its Climate Change, Water and Food Security report.

Farmers can reduce water use and optimize irrigation by turning to earlier or later planting, while yields and productivity can be improved by shifting to soil moisture conservation practices, the report said.

Planting deep-rooted crops would allow farmers to better exploit available soil moisture.

Mixed agro-forestry systems also hold promise because they sequester carbon and offer wind protection, improved soil conservation and shade, which reduces ground temperatures and evaporation.

Small-scale farmers in developing countries, who already produce yields far below their potential, face an uphill struggle in adopting such strategies because of limited access to capital, the report said.

FAO said too little is known about the impact that climate change will have on water for agriculture at the regional and sub-regional levels and that "mapping vulnerability is a key task at national and regional levels."