This paper presents field results from three rainy seasons (1998-2000), receiving a cumulative seasonal rainfall ranging from 418 to 667 mm. Supplemental irrigation ranging from 60 to 90 mm per season was applied based on actual occurrence of dry-spell induced crop water stress. Results are presented on the effects on Sorghum (Sorghum Bicolor (L.)) yields under supplemental irrigation and soil nutrient application in an on-farm experiment in northern Burkina Faso. The focus is on dry-spell bridging and water and nutrient interactions on biomass productivity.