DECOMPOSITION OF LEAVES OF 6 MULTIPURPOSE TREE SPECIES IN CHIPATA, ZAMBIA

The objectives of the study were to investigate (1) whether decomposition rates of foliage differs among the multipurpose trees (MPTs) Leucaena leucocephala (LEL), Flemingia congesta (FLC), Pericopsis angolensis (PEA), Cassia siamea (CAS), Sesbania sesban (SES) and Gliricidia sepium (GLS), and (2) whether nitrogen (N) concentrations and mineralization in the foliage differ among these MPTs. Litter bags containing foliage from each species were arranged in a randomized block design with three replicates and sampled at 0, 2, 4, 8 and 12 weeks in a repeated measures manner, after placement to determine decomposition and N release. Estimates were made of N mineralization and equations were developed for predicting rate of decomposition, N concentration, and N content for each species. Significant differences existed in decomposition rates (GLS > LEL = SES > CAS > PEA = FLC) and N contents (GLS = LEL > SES > PEA = FLC = CAS). No significant differences existed in N concentration between the species. Based on these results, GLS and LEL showed the greatest potential for use as green manures. Further studies are required to determine time, amounts and method of green manure application.