A review on the effect of green manure on crop performance and yield in the Savanna region of Nigeria was conducted in some parts of the Savanna region through the collection from some of the research works carried out by different researchers. In view of the increasing wave of scarcity and high cost of synthetic fertilizers in Nigeria, following changes in Government policies on subsidy, procurement and distribution of inorganic fertilizers, consequently, resource – poor farmers can no longer afford their use to maintain soil fertility. Therefore, the evaluation of suitability of certain green manure in maintaining and improving soil fertility and crop productivity is imperative. Thus, this study was undertaken with a view to appraising effects of green manure on crop performance and yields. More so that one of the major constraints to crop production in the tropics especially in Northern Savanna region of Nigeria is the inherently low fertility status of most of the soils. Thereby necessitated growing search for many soil fertility improvement techniques. Therefore, adoption of green manure cropping system, which is environmentally friendly and soil improver will be the best option for sustainable crop performance and yield in the Northern Savanna. Hence, it is likely to conclude that introduction of legume green manures in cropping systems would be ecologically friendly and economically justifiable
