With 852 million chronically hungry people in the world today and a global population expected to increase by an additional 2 billion people by 2030, feeding this growing population and reducing hunger will only be possible if agricultural yields can be significantly increased. And increased food production will depend largely on investment in the control of water.

Getting more crop per drop

Agriculture is the largest consumer of the earth’s freshwater, responsible for around 70 percent of all freshwater withdrawals. As water resources shrink and competition for water from other sectors grows, the agriculture sector faces a complex challenge: producing more food of better quality while using less water and ensuring environmental sustainability.

The availability of water varies tremendously by region, and in some regions it is exceedingly scarce. Even in areas with limited water supplies, however, irrigation can vastly increase agricultural productivity and is crucial to improving food security.

By far, most of the water used to grow crops is derived from rainfed soil moisture. Irrigation provides only about 10 percent of agricultural water. It plays a vital role, however. When rains are weak or erratic, irrigation can ensure crop production and allow farmers to diversify and invest in more productive forms of agriculture -- which means not just improved food security and nutrition for rural populations but also job creation, better earnings and increased trade opportunities.

Indeed, the productivity of irrigated land is about three times higher than that of rainfed land. Though irrigation covers just around 20 percent of the world’s cropland, irrigated land contributes 40 percent of total food production.

Underused water resources in parts of Africa offer great potential for irrigation, especially using simple and inexpensive technologies. Africa uses less than 6 percent of its renewable water resources, compared with 20 percent in Asia. And only 7 percent of the arable land in Africa is irrigated, compared with 38 percent in Asia.

Improving efficiency

Small-scale water harnessing, irrigation and drainage works carried out at the rural community level using local labour offer an effective and low-cost option for improved water control. Such solutions need not be complicated, and sometimes involve small changes to the way things are done. Water harvesting – collecting water in structures ranging from furrows to small dams – allows farmers to conserve rainwater and direct it to crops. Similarly, directing water only where it is needed, as in drip irrigation, is more efficient than flooding entire fields or using sprinklers.

“Carefully designed water management strategies and programmes aimed at improving the efficiency and productivity of water use need to be put in place,” says Pasquale Steduto, Chief of FAO’s Water Resources, Development and Management Service.

Large-scale public irrigation schemes, which represent the bulk of the world’s irrigation, have contributed to poverty alleviation and boosted agricultural production in Asia, the Near East and parts of Latin America, but many of these ageing systems are currently facing the challenge of modernization.

“Upgraded infrastructures and increased flexibility and reliability of water services are required to meet changing market conditions and social and environmental priorities,” says Steduto.

“Sustainable economic growth in most developing countries can only be achieved through the development of a strong agricultural sector,” adds FAO Assistant Director-General Louise Fresco. “Considerable public and private investment in infrastructure, technology and development of farmers’ and water managers’ technical capacities is needed to increase food production in a sustainable way. Improved water control is the growth engine for rural development.”