My expertise is on farming systems research, combining agricultural and environmental sciences. The focus has been on developing countries, mainly Sub-Saharan Africa. I use modelling, field experimentation and surveys to investigate the determinants of landscape productivity and the impacts on food security. The last 6 years, I have conducted research on adaptation and mitigation of climate change on smallholder systems (http://samples.ccafs.cgiar.org/). This research looks for incentives for land users to improve crop and livestock productivity and to reduce GHG emissions to the atmosphere.