Former positions Post Doctoral Researcher via the Technical University Dresden / Germany in Loja, Ecuador. Designing a multi-layered land-use risk classification system for the Andes (2 years). Scientific researcher nutrients and water at the Institute of Applied Plant Research (WUR) at Lelystad. Research on Nitrogen losses in vegetable and crop production systems (3 years). Associate expert at the International Centre for Research in Agroforestry (ICRAF) in Maseno / Western Kenya. Research into tree-crop interactions in low-input small-farmers¿ agroforestry systems, with special attention on water-phosphorus and rootexudate-phosphorus interactions. This research was used to write a PhD thesis at the soil quality department (WUR) (6.5 years). Temporary fellow at the department of Tropical Crop Science (WUR), conducting literature research into the differences in water balances of trees and crops in West Africa (0.5 year). Student at the "Projet Production Soudano-Sahélienne" / Niono (Mali). Conducting research on the influence of parkland trees on the soil and the herbaceous layer in the Southern Sahel, with special attention to phosphorus and soil organic matter. (0.5 year) Student at the ¿Institut Sénégalais des Recherches Agricoles¿ (ISRA) / Djibelor (Casamance / Senegal). Research on soil science: Characterization of spatial and temporal variation in saline acid sulphate soils along the Casamance River, and their possibilities for rice production by local small farmers (0.5 year).