78 Economic dimensions and socio-cultural patterns
towork together toward a tangible constructive goal; and reduces hunger and
malnutrition in poor areas. (C) Culturally, it: enhances aesthetics; discourages
dumping debris on vacant spots; provides flowers and other bits of nature to
enrich living spaces; and teaches urban children about soil, plant growth, ani-
mals, natural pest controls (Mougeot 2005), and food. (D) Environmentally, urban
agriculture: provides greenspace; reduces air temperature and pollutant buildup;
absorbs rainwater that reduces flooding and stormwater pollutant runoff; and
recycles wastes such as garbage from food markets and restaurants to fertilize
crop fields or to grow pigs.
Problems with urban agriculture, of course, also exist. Pesticides and excess
nitrogen fertilizer seep down and pollute the groundwater. Water used for irri-
gation may be rich in pathogenic bacteria from human wastewater. In dry cli-
mates much scarce water is used. Insect and other vectors carrying malaria,
chagas disease, and many other public health menaces are enhanced, especially
by poor-drainage water in tropical cities (Robinson1996,Asomani-Boateng2002,
Asare Afraneet al.2004;Burton Singer, personal communication). Plants grown
on chemically polluted vacant lots or brownfield areas may absorb high levels
of heavy metals and other toxins (Kirkwood2001,Berger2006). Aquaculture
normally produces prodigious amounts of food, yet, where human wastewater
containing pathogenic bacteria is used to support the production, a cultural
aversion to its use has to be balanced against the prevalence of poverty and food
shortage (Costa-Pierceet al.2005).
Remnantfarmland areasin suburban or peri-urban areas also provide many
values to their communities (Formanet al.2004). These include diverse farm
products, and the potential for production on prime agricultural soils in the
future. The historical symbolism of farmland in town, the active roles of farm
families, the educational dimensions of farms, and the availability and conve-
nience of fresh produce in town farm-stands are important values. Agricultural
areas near roads, railroads, paths, and scenic points contribute significantly to
preserving the open and rural character of a town. They enhance game pop-
ulations, and increase the town’s wildlife biodiversity by providing habitat for
species requiring large open areas. Perhaps most important isthe ethics of pro-
tecting prime food-producing areas in a world of extensive and growing hunger.
Or maybeteachingchildrenlies at the core of culture. Urban agriculture teaches
where food comes from, how one’s own plants grow and change, what happens
after flowers open, where seeds are hiding, what grubs look like, how fast weeds
grow,what pests appear, which flowers will help control pests, what birds do
in gardens, how nice soil is compared with dirt, and how slimy earthworms
feel. Collective knowledge about food and nature is passed from generation to
generation in urban gardens.