Nitrogen contribution of some selected legumes to a sorghum based cropping system in the southern Guinea savanna of Nigeria

In Nigeria, sorghum is a widely produced and consumed staple in the savanna and it is an important cereal in terms of both the volume of production and total land devoted to the crop. A major stress for sorghum production in the Savanna apart from rainfall is Nitrogen (N). This is because the soils are characteristically low in organic matter and subjected to very rapid soil nutrient depletion and degradation. Field experiments to assess the Nitrogen (N) contribution of legumes to a sorghum based cropping system in the southern Guinea savanna of Nigeria were carried out during the 2004 and 2005 cropping seasons. The studies were conducted at the experimental station of the National Cereals Research Institute, Badeggi, Nigeria.