Plant-animal fabric flows and production efficiencies in urban and peri-urban agriculture in a West African city.

Funding: German Research Foundation
Project duration: 2006-2009
Editing: Martina Predotov, Diogo Rodrigue V. Cao

Against the background of the strong growth of African cities and related supply and environmental problems, urban and peri-urban agriculture (UPA), which is developing particularly strongly there, is gaining increasing scientific interest. In contrast to the subsistence-oriented land use systems prevailing on extremely nutrient-poor, erosion-prone soils of the hinterland, UPA is characterized by high input intensities. However, there is currently little basic research on productivity, material turnover and environmental externalities of UPA, which combines livestock and crop production systems. In this research project, material flows in the UPA will be measured and their main parameters modeled in exemplary selected households using the example of Niamey, the capital of Niger. These investigations will then be used to examine proposals for increasing resource efficiency. To this end, in a first step, horizontal inputs and losses of nitrogen (N), phosphorus (P), and potassium (K) at the soil-plant-animal interfaces will be recorded over the course of the year on 20 example farms selected according to their degree of integration of animal husbandry and crop production. At some of these farms, atmospheric emissions (denitrification and ammonia losses) will be determined at representative times using a trace-glass photoacoustic analyzer, and seepage-related nutrient losses (N, P, and K) will be measured by installing Si-carbide suction plates. In a second step, the influence of specific improvement measures in material management (use of a bedding of straw and rock phosphate in stationary animal husbandry, controlled composting of animal manure) on atmospheric N losses and manure quality will be tested. In the third step, the influence of different intensity and integration levels of UPA on the recorded substance fluxes in the soil-plant-animal-environment continuum will be mapped by means of a bio-physical model.