Tropical legumes traditionally have been used in agroforestry systems because of their potential to add organic matter and nutrients. The objective of this study was to determine the decomposition and nutrient release rates from the litter of the prunings of Cratylia argentea, Erythrina berteroana and Flemingia macrophylla, used as green manure in an organic banana alley-cropping system at EARTH University. To determine nutrient release and decomposition rates, litterbags were placed under the plantation’s canopy. Samples were collected every two weeks during a period of twenty-two weeks. Decomposition and nutrient release rates for N and K adjusted using a power trend line model while P did not adjust. The decomposition rate and N release order was the following: E. berteroana > C. argentea > F. macrophylla. K release rate order was C. argentea > E. berteroana > F. macrophylla. Carbon fixation, per year, of the prunings was 3600 kg/ha for the B-Forest system, 3378 kg/ha for the B-Orchard system, 3510 kg/ha for the B-Legume system, 2225 kg/ha for the B-Laurel system.