Modern colonial cities were planned and managed to have food production on the outskirts of the city using "modern" agriculture and producing "European" crops. The great Scottish urban thinker, Patrick Geddes, condemned these when he visited the city of Indore in India during the First World War: "from the callous, contemptuous city bureaucrat at Delhi, I have now to tackle here the well-intentioned fanatic of sanitation-perhaps an even tougher proposition. Instead of the 19th century European panacea of "Everything to the sewer!"…the right maxim for India is the traditional rural one of

"Everything to the soil!"

Urban agriculture (UA) gained importance in the 1980s throughout the world with almost a three-fold increase in Moscow, Russia and Dar es Salaam, Tanzania and other cities of Africa as massive shifts of urban land from open space, institutional and transportation was used for agricultural production. In the poorest of poor countries such as Kenya and Tanzania, three of every five families in towns and cities are engaged in urban agriculture. The trend also spread to cities such as Bangkok where 60% of the land was farmed. Throughout the world there is a long tradition of farming intensively in the cities. In all parts of the world, ancient civilisations developed urban agricultural systems to feed the cities. Examples include Ghana, India, China, Iraq, Java, Pakistan, Guatemala, Mexico and Peru. The intensive production of perishables, small livestock, fish and poultry within the city was essential to city life. Grains, fruits and vegetables were shipped from the nearby countryside. In certain cultures crops such as mushrooms and medicinal and culinary herbs were specially developed in urban areas. In Latin America, Aztec, Mayan and Incan cities were self-reliant in perishable fruits and vegetables but also raised some grains within the confined hinterland. Similarly towns and cities of early civilisations of Java and Indus valley show traces of high-intensity irrigated farming systems. The Javanese aqua-terra system combining multi-crop water system and soil farming systems have still survived in some areas.

Like the Aztec aqua-terra chinampas in Mexico. At Tenochititlan, the site of Mexico city today, the Spanish invaders in the 15th century found the largest city they had known at the time. A principal source of food production was a form of aqua-terra farming known as chinampas. Irrigation systems helped farmers to produce three crops a year in areas that today give only two crops. These city farmers also had sophisticated methods of soil improvement and insect control. Manula describe the use of human and animal waste in mixture with other waste materials to be used as inputs in agriculture. Cities' wastewater flowed into tanks and from tanks to irrigate fields.

Machu Picchu, the lost city of the Inca appears to have been self-sufficient in food within walking distance. The main city also had a suburban area that carried out intensive agriculture.

In the ancient systems various techniques such as sun reflectors in Tigris and Euphrates were used to heat the soil. At Machu Picchu standing water of aqua-terra systems held off mountain frost. In Bolivia today the sun’s heat is stored in the adobe walls of the greenhouse even today.

Cultures throughout history have used their dwellings, workplaces, and communal spaces to produce food and other basic needs. In Yemen, for example, some towns and cities have integrated high-rise architecture with organic urban gardens over the last two thousand years. These gardens use traditional techniques of stacking layers of shrubs, vegetables, herbs and root crops under a canopy of date palms —mimicking the ecological structure of natural forests.

In Europe compost using horse manure has been used over the years to heat raised vegetable beds. Before modern urban sanitation systems were developed in the late 19th century, urban agriculture was the main treatment and disposal of urban waste. Food was delivered by donkey carts to the markets and the city wastes in turn were delivered to the fields — both rural and urban.

>> The struggle to sanitise the cities has been waged for more than a decade now. But the systems are unsustainable because they shift increasing volumes of waste from one location to another within the urban ecosystem >>

For example, the Marais farming system of 19th century Paris. 100 years ago a sixth of the area of Paris was used to produce annually more than 100,000 tonnes of high-value of of season salad crops. A sustainable cropping pattern as it used approximately 1 million tones of stable manure produced each year by horses, which provided power for the city's transport system. This system became famous in Europe in the late 19th century that very intensive horticulture using heavy inputs of biological origin is still called French gardening today. In energy, mass and money terms the inputs and output of the Parisian urban agro-ecosystem exceed those of present day fully industrialised crop production. In this system 3-6 harvests a year were obtained through inter-cropping. Year round production was made possible by the heat and carbon dioxide released through the manure fermentation, shelter by two-metre high walls, glass-covered frames and bell-shaped glass and by straw mats used to cover the crops during severe winter. 50 kg of per capita of fresh salads, vegetables and fruits were produced annually which exceeded the levels of consumption of these foods. Products were exported to as far as London. The system reached its maximum peak in the plate 19th century, its rapid decline can be explained by three factors: the virtual replacement of the horse by the motor car, competition for land within the city and competition from areas with more favourable climate outside the city-facilitated by the improvement in the transport system. This system of cultivation remains one of the most productive ones ever documented. The productive biological recycling of waste products of the city's transport system contrasts with requirements and consequences of the present day urban ecosystems. But today the accepted idea has become the "the city beautiful" or the "city clean". Modern agricultural ways have replaced the traditional ones in many developing cities. But there is quite revolution coming about as there are many cities who are in a process to adopt the biointensive marai system.

The struggle to sanitise the cities has been waged for more than a decade now. But the systems are unsustainable because they shift increasing volumes of waste from one location to another within the urban ecosystem. With multiplication of urban populations and the food systems becoming more unreliable urban hunger multiplied with urban growth. In response UA became the solution to the city.

(Taken from the book, Urban Agriculture: Food, Jobs and Sustainable Cities, UNDP)