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Productivity of grain legumes on sandy soils of southern Africa is critically limited by marginal fertilisation. Effects of co-applying phosphorus (P)-based mineral fertilisers and organic nutrient resources to cowpea (Vigna unguiculata (L.) Walp.) and soyabean (Glycine max L.) were investigated on smallholder farms in eastern Zimbabwe over two years. Over 70% of the surveyed farmers grew cowpea without fertilisation. Fertilisation of legumes with one or more nutrient resources increased shoot biomass productivity by between 20% and 300% relative to the non-fertilised control. Fertilised soyabean and cowpea yielded 2.2 t grain ha -1 and 2.5 t grain ha -1 , respectively, translating to more than double the yields of unfertilised controls. In contrast, sole application of either mineral P-containing fertilisers or organic nutrient resources yielded less than 1 t ha -1 …