L’agriculture urbaine et périurbaine est une expression de plus en plus utilisée depuis quelque temps, même si on ne se préoccupe guère d’en donner une définition correcte. La présente contribution vise à analyser la notion d’agriculture urbaine et périurbaine au-delà de ses limites géographiques; elle étudie les profits des agriculteurs urbains, les obstacles qu’ils doivent surmonter et, finalement, leur rôle en tant que producteurs de denrées alimentaires dans les villes de demain.
Los términos de agricultura urbana y periurbana se utilizan con una frecuencia cada vez mayor, pero son escasos los intentos que se han hecho de dar una definición apropiada. En el presente artículo se analiza el concepto de agricultura urbana y periurbana más allá de su límite geográfico; se consideran los beneficios de los agricultores urbanos, las limitaciones que encuentran y su función como productores de alimentos en las aldeas y ciudades en los próximos años.
Tim Aldington
Senior Technical Adviser and Secretary of the Committee on Agriculture
FAO Agriculture Department
Urban and peri-urban agriculture are terms that are used with increasing frequency, but only in a few cases is the proper definition intended. This contribution attempts to analyse the concept of urban and peri-urban agriculture within its specific geographical boundary. It considers the benefits of urban farmers as well as the constraints they face in their role as food producers in towns and cities of the near future.
Now that this seeming oxymoron – urban agriculture – is being swept enthusiastically into the development lexicons, perhaps some definitional rigour is called for to explain what it is we are talking about. I personally (others may disagree) like to define urban agriculture as farming and related activities that take place within the purview of urban authorities.
By this last term it is meant the panoply of laws and regulations regarding land use and tenurial rights, use of water, the environment, etc, that have been established and are operated by urban or municipal authorities. Urban agriculture takes place within certain boundaries which may extend quite far from an urban centre, while peri-urban agriculture takes place beyond that often geographically precise boundary, although its own outer boundary may be less well defined.
This is so because peri-urban agriculture is farming and related activities that are significantly influenced by urban areas or municipalities. Such influence is normally expressed through market forces, i.e. through demand for types of food products such as fresh fruit and vegetables and dairy produce. However, the extent of such influence is affected by transport systems linked to the municipality concerned. There is also some urban influence exerted on agriculture through the availability of waste products, typically domestic waste and waste water with potential for use in agriculture. Hence, typically around urban peripheries, intensive horticultural and livestock farming may be found, perhaps with woodlots, gradually tapering off into regular, more extensive farming systems as the urban influence wanes.
The concern for definitions is not mere pedantry but is needed to explain the issues affecting urban agriculture and peri-urban agricultural producers. They benefit from the relative nearness and strength of urban markets derived from urban demand. They may benefit from developed communications systems, but not always. They may also benefit from having better access – than rural areas – to agricultural inputs, including water, although this is not always so and the water can be expensive. They almost certainly suffer from restrictive urban planning, land use and environmental regulations, and probably from a lack of secure tenurial and property rights.
They are also likely to suffer from poor financial services – the services may exist but not be attuned to agriculture; and a lack of information – the relevant ministries may be physically close but existing research and extension services will have a rural focus. They will also suffer from urban environmental pollution such as heavy metals from lead gasoline and other atmospheric pollutants as well as and polluted water supplies. Finding out about such benefits and constraints is a necessary step towards formulating means of exploitation and solutions to problems.
Why is urban agriculture important? It is not to supply the mass of the urban population with basic foods. A simple calculation will explain. Take a smallish city of approximately 1 million inhabitants and allow 150 kg per caput/annum of cereals – rather a minimum ration. This adds up to 150 000 tonnes/annum. At a modest average yield of 3 tonnes/ha (implying a reasonable rainfall and moderately fertile soils), such a quantity would require 50 000 ha of harvested land or 500 km2,
or 550 km2 to allow for post harvest losses and seed needs. This area is a circle with a radius of about 13 km and a diameter of 26 km. In addition, allowance has to be made for the built-on area.
This calculation explains the relatively large "footprint" of even quite demographically small urban centres, reaching out beyond the peri-urban areas. But urban agriculture can be an important provider of particular food products, which typically have income elasticities of demand that are higher than those for basic foods such as cereals. High growth rates of urban populations coupled with rising per caput urban incomes (this used to be the case – it is less so now) translate into high rates of growth in demand. For example, in Nairobi in the early 1970s the demand for fresh milk was increasing by more than 7 percent per year, which is high for a food product and difficult to match on the supply side over an extended period.
It is not only the supply of certain food products that makes urban agriculture important, but also who produces and consumes them. Producing such foods provides an opportunity for otherwise unemployed and poor people to earn an income and have access to a variety of fresh foods. The increased supply on the market will tend to hold down consumer prices and improve access – all of which are positive points.
Urban and particularly peri-urban agriculture also can be useful in recycling urban solid and liquid wastes. Indeed, some see urban agriculture as the only means of utilizing such materials and enabling plant nutrients and water to be recycled. There are caveats of course. Care must be taken not to use raw, untreated wastes on food products for direct consumption. However, woodlots on the periphery of a city offer opportunities for converting such waste, particularly liquid wastes, into fuelwood and building materials.
Enough said. With the world’s population set to be about two-thirds urbanized by 2020, urban and peri-urban agriculture will increase in importance without the also important role of the towns and cities in promoting rural development being neglected. The main issue is to help urban dwellers be able to seize the opportunities they see in urban agriculture. Doing so will mean educating urban planners and municipal administrators on the potentially useful aspects of urban agriculture and carefully researching the constraints bearing on those potential oxymorons – the urban farmers.