Towards the African Green Revolution: Crop Yields and Nutrient Budgets.

In order to achieve the Millennium Development Goal (MDG) on halving the number of people suffering from hunger in Africa, both the Hunger Task Force of the UN Millennium Project and the African Green Revolution target a substantial increase in crop production from the current cereal yields of below 1t ha^-1 to 3t ha^-1. Meeting such a target requires drastic changes in the current agriculture practices including the supply of nutrients to currently depleted soils that prevail in most rural areas. The Millennium Villages Project, initiated in 2005 as a proof of concept, applies the recommendations of the Millennium Project Task Forces in a multisectorial approach.  The entry point of the agriculture sector has been to support farmers with subsidized fertilizers, improved crop germplasm and intensive training on appropriate agronomic practices. This resulted in average yields of more than 3 t ha^-1 in all sites where maize is the major crop.  Over 75% of the farms had maize yields of 3 t ha^-1 and less than 10% of the households had yields lower than 2 t ha^-1.  In addition to measuring crop yields, a quantitative estimate of nitrogen and phosphorus inputs and outputs is undertaken to assess the major pathways of nutrients applied as fertilizers.