The Western Kenya region is one of the most populated rural regions of the world. The soils are depleted of nitrogen (N) and phosphorus (P). Fertility replenishment is therefore necessary, in order to increase food production. Although inorganic fertilisers are important in the restoration of soil fertility, their use, especially N fertilisers, is quite low on smallholder farms due to their high cost. Biological Nz-fixation can contribute to soil fertility enhancement, thereby improving productivity. Combining legume green manures with other organic or inorganic sources of nutrients may improve crop yields by increasing nutrient use efficiency. Three factors- legume green manure (GM), Farm Yard Manure (FYM), and inorganic nitrogen (N) were evaluated onstation in 1998 and 1999 at the Regional Research Centre, Kakamega, Western Kenya, in a 3 x 2 x 3 factorial fitted in a Randomized Complete Block Design (RCBD) replicated three times. Green manure was at three levels (no GM, Crotalaria ochroleuca, and Mucuna pruriens), FYM at two levels (0 and 2.5 t ha-l), and N at three levels (0, and 30 kg N ha-l). Out ofthe three factors investigated, only legume treatments produced significant (p=0.05) effects on maize grain yield. Averaged over two years, inclusion of GM increased grain yield by 1.5 t ha-l, from 5.1 to 6.6 t ha-l. Though not significant, N had a positive effect on both GM and FYM. For GM, grain yield was -2.5 t ha-l higher at 15 and 30 kg N ha-l compared with no N, while FYM had a marginal grain yield increase of 1.0 t ha-l at the highest N rate of 30 kg N ha-l. These results suggest that maize grain yield can be greatly improved by integrating GM, FYM and inorganic nitrogen in the of management soil fertility.