This study was carried out to determine the green manure values of the most suitable forage legumes for growing as winter catch crops under irrigated conditions of Çarsamba Plain. The highest (maize and sunflower) grain yield grown as a summer main crop after green manuring were obtained from green manuring of whole plants of narbonne vetch and common vetch (in maize, 974.2 kg/da and 963.3 kg/da; in sunflower, 493.8 kg/da and 492.5 kg/da). These green manure plants increased the yield of maize 51.7 and 50.0 % and of sunflower 36.8 and 36.4 %, respectively. It was determined that these high yields on the main crops after green manuring were equal to the yields (in maize, 943.7 kg/da and 1060.0 kg/da; in sunflower, 436.7 kg/da and 531.5 kg/da) after 10 kg and 20 kg nitrogenous fertilizer applications per decare. In addition to these results, it was found that rice chaff had no significant effect on the yield of main crops, and tobacco dust can be used as green manure.