Résumé
The roles of urban agriculture in the Antananarivo district (Madagascar) are being studied in a multidisciplinary and multi-institutional research project. Agriculture is diverse and production systems vary in function of the quantitative and qualitative water disponibilities. Pluriactivity is frequent as well as the diversity of uses of agricultural resources. The food supply function for the city is essential as for many developing countries, greater and more diverse for vegetables than for rice production, but this later is significant at certain periods of the year. Other functions of urban agricultures are emerging: plain rice production plays a recognised role for protecting the city against inundations; urban solid waster use by agricultures has been successfully experimented and could open new relationship between the city and its agricultures. Used water may be valorised by some agricultural productions but industrial water pollution seriously damage yields and quality of agricultural products as well as human health. New roles for landscape and patrimony appear locally.