ANDREAS BUERKERT, BERND MARSCHNER, CHRISTOPH STEINER, EVA SCHLECHT, MARC WICHERN, NIKOLAUS SCHAREIKA, WILHELM LÖWENSTEIN, AXEL W. DRESCHER, RÜDIGER GLASER, GORDANA KRANJAC-BERISAVLJEVIC, ZACHARIA GNANKAMBARY, PAY DRECHSEL, DÉSIRÉ JEAN-PASCAL LOMPO
University of Kassel, Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics, Germany
Ruhr-Universität Bochum, Institut of Geography, Soil Science / Soil Ecology, Germany
University of Kassel / Georg-August-Universität Göttingen, Animal Husbandry in the Tropics and Subtropics, Germany
Ruhr-Universität Bochum, Institute of Urban Water Management and Environmental Engineering, Germany
Georg-August-Universität Göttingen, Institute for Social and Cultural Anthropology, Germany
Ruhr-Universität Bochum, Institute of Development Research and Development Policy, Germany
University of Freiburg, Dept. of Environmental Social Sciences and Geography; Physical Geography , Germany
University for Development Studies, Ghana
INERA, Bureau National des Sols, Burkina Faso
International Water Management Institute (IWMI), Water Quality, Health and Environment, Sri Lanka
Food security in West Africa not only depends on productivity increases in marginal rural areas, but also on enhanced use of intensively farmed agricultural ``niche'' lands such as the urban and peri-urban spaces. They are characterised by easy market access and input availability which allows self"=reinforcing processes of agricultural intensification. However, too little is known about resource use efficiencies, matter flows and negative externalities in these systems. Starting from general assessments (status quo analyses), the African-German UrbanFoodPlus (UFP) network develops and tests site"=specific, farmer"=tailored innovations. These directly address the above mentioned knowledge gaps in the four West African cities of Ouagadougou (Burkina Faso), Tamale (Ghana), Bamako (Mali), and Bamenda (Cameroon).
At all locations farmers attempt to cope with increasing land pressure by cultivating along electrical power lines, on public property, and on undeveloped private land. While a large proportion of the major food crops origin from the countryside, leafy vegetables and milk are mainly produced in the cities and peri-urban areas. Determined by water availability cultivation patterns strongly vary across the year. In Tamale staple crop production is vital in the rainy season while commercial vegetable production dominates during the dry months. Livestock production systems are highly diverse in both cities while dairy and commercial pig farming predominates in Ouagadougou.
Urban agriculture is also characterised by high nutrient input rates through organic and inorganic fertilisers and reliance on irrigation. Biochar produced from corn cobs, rice husk, and saw dust was characterised and used for direct land application, filtering of irrigation water, and for co-composting. Biochar improved crop growth in both cities (up to 50%) and can be used as an effective filter material for waste water (2.5-3 log10 units reduction in pathogens in a two stage system). A market model was established using secondary time series data (production and consumption) of the past 30 years. This will allow a site"=specific economic evaluation of the impact of productivity enhancing technologies.
Keywords: Food security, irrigation, nutrient fluxes, soil fertility, urbanisation