The coastal polders of Bangladesh are characterized by extremes in terms of both challenges and opportunities. The polders are home to about 8 million people, where 85% of rural householders live under the national poverty line. The polders are subjected to flooding during the rainy season; drought and salinity during the dry season, and cyclones. In addition, the impacts of climate change, especially sea level rise, will be most severe in this region.

The important position and role of mixed farming systems in land use intensification in subSaharan Africa is reviewed. This is done by examining the current situation that is followed with a justification for mixed farming. Further sections follow on changing patterns of land use, including the effects of tsetse flies and trypanosomiasis, and on constraints to further crop-livestock integration.

The Ganges Basin Development Challenge (GBDC) Program of the CGIAR Challenge Program for Water and Food is focusing on improving livelihoods and increasing productivity sustainably in the coastal polder zone, and has developed and tested innovative cropping systems and water management practices suited to the local conditions.Before a new cropping system can be recommended, it is important to identify its “extrapolation domain,” which determines where it could be successful.