International Livestock Research Institute (ILRI) (part of CGIAR), Kenya. In cooperation with the Institute of Meteorology and Climate Research (IMK-IFU), Karlsruhe Institute of Technology. ILRI works since decades on livestock production systems in Africa, with a particular focus on East Africa, including the Lake Victoria region. In the last years ILRI established a new research direction focusing on nutrient balances, use of manure for feed food production, and quantifying environmental footprints of livestock production systems including effects of land use change. In this context ILRI also worked on nitrogen balances for the Lake Victoria watershed and entire Africa. In close cooperation with the Institute of Meteorology and Climate Research (IMK-IFU), ILRI has the capacity to run biogeochemical models at regional scale for quantifying and assessing N flows.