In this paper, the author discusses urban agriculturalfunctions and their changes in the metropolitan area of Tokyo prefecture. Following this discussion, the author analyzes some factors that have caused changes infunctions of urban agriculture, and she demonstrates the multi-functional system of urban agriculture with a case study in the Nishi-Ooizumi area of Nerima ward. Nerima is located in the northwestern suburbs of metropolitan Tokyo about ten kilometersfrom the metropolitan center, and Nishi-Ooizumi is located in the northwestern part of the ward. Although this area has had good accessibility to the metropolitan center in terms of commuting, agriculture has continued to be practiced since the 1970s. Productive green land, an importantfactor in the sustainability of urban agriculture, comprised 66.4 percent of all thefarmland in Nerima ward in 1997.
Based onfield surveys and land use maps, somefunctions in terms of both agriculture andfarmland wereidentified in Nishi-Ooizumi area. They have beenclassified intofive types: agricultural production, amenity and environment, disaster prevention, leisure activity, and land supply. Changes in these functions have been divided into threeperiods: urban fringe agriculture, early urban agriculture, and growth of urban agriculture. In each period, the author considers the interaction among functions and the conditions affecting them.
In the period of urbanfringe agriculture, before the early 1960s, farmland was the dominant use of land in the Nishi-Ooizumi area, and agriculture there was mono-functional and belonged to the agricultural production function. In the period of early urban agriculture, the latter 1960s and the 1970s, the land supplyfunction dominated because of high economic growth and the enforcement of the City Planning Act, but because some agriculture in the area fell under the agricultural production function, there was a dual functional system at this time. In the period of urban agriculture growth, during andafter the 1980s, agriculture continued tofall into the agricultural production and land supply functions, but the other three functions-amenity and environment, disaster prevention, and leisure-were introduced at this time. Thus, thesefivefunctions have interacted with eachother and created a multi-functional system in the last two decades. This multifunctionalization was caused by rising land prices, a review of measures against calamities after the Hanshin earthquake in 1995, and environmental conservation.
The land supply function has been regarded as detrimental for sustainable urban agriculture because it also appropriated land for nonagricultural use and thus contributed to the decline of agriculture. Nevertheless, urban farmland also performed an important function in getting funds for farmers. Accordingly, sustainability of urban agriculture depended on the land supply function.
In summary, the differences in function in each period were caused by the influence of enforcement of laws, business conditions, and urbanization of the area. Although urban agriculture originally was mono-functional and fell under the agricultural production function, it came to include other functions as a dual-functional and then a multi-functional system.
