With the world's cities growing rapidly, farming in and around urban areas needs to play a bigger role in feeding city populations, the United Nations Food and Agriculture Organisation (FAO) said on World Environment Day (June 5. 2009).

Urban and peri-urban farms already supply food to about 700 million city dwellers -- one-quarter of the world's urban population.

FAO said that nearly all of the world's population growth between now and 2030 will be concentrated in urban areas in developing countries. By then almost 60% of people in developing countries will live in cities.

Urban agriculture involves using small areas such as vacant lots, gardens or roof tops in the city for growing crops and even for raising small livestock or milk cows. It can take many forms, from small "micro-gardens" to larger operations.

A related practice is "peri-urban agriculture," consisting of farm units near cities that grow vegetables, raise chickens or livestock, and produce milk and eggs. Urbanization poses challenges, FAO said. Poverty rates in many cities are rising, and ever-larger numbers of city residents face difficulties accessing the food they need. In some developing countries, the urban poor spend 60% or more of their income on food.

Problems are compounded by poor infrastructure for transporting food to urban centers. Long distances, bad roads, and urban crowding cause spoilage of 10 to 30 percent of produce in transit.

As new, urban lifestyles lead greater numbers of people to consume more fats and less fiber, more fast food and fewer home-cooked meals, developing countries face a double challenge -- widespread hunger on the one hand and rapid increases in obesity, diabetes, cardiovascular diseases and other diet-related diseases on the other.

One part of the solution was growing food in or near cities, FAO said. Urban and peri-urban agriculture can help improve food security in several ways: growing food at home or via a cooperative reduces the cost burden of acquiring food for the poor, puts more food within their reach, and reduces seasonal gaps in fresh produce.

Also, by increasing the diversity and quality of food consumed, it can significantly improve the quality of urban diets. Sales of surplus produce, meanwhile, can generate income that can be used to buy more food. Even small "micro-gardens" can bring in up to $3 a day for poor families, according to FAO.

An estimated 1.2 billion people live on less than one dollar per day. Almost three billion make do on less than two dollars a day.

In the city of Dar es Salaam, Tanzania, 1600 acres (650 hectares) are used for vegetable production, providing income to more than 4,000 farmers.

Eleven square feet (one square meter) rooftop tomato gardens introduced by an FAO project in Dakar, Senegal are yielding 40 to 66 pounds (18 to 30 kilos) of tomatoes per year.

Yet despite their growing importance, urban and peri-urban agriculture are still subject to numerous constraints, such as lack of suitable land, uncertainty about land tenure, insufficient access to irrigation water of appropriate quality, inadequate know-how, and low investment. END.