Comparative analysis of leaf litter decomposition and nutrient release patterns of bamboo and traditional species in agroforestry system in Ghana

Abstract

Understanding leaf litter decomposition dynamics is imperative owing to nutrient release rates and synchronization. The overarching aim is to sustainably manage agroforestry systems and ensure environmental integrity. Therefore, this study aimed at determining the decomposition and nutrient release of leaves of different bamboo species (Oxytenanthera abyssinica, Bambusa balcooa, Bambusa vulgaris), rarely used woody perennials in agroforestry system in Ghana, and compared with commonly used agroforestry species; Albizia lebbeck, Senna siamea, Gliricidia sepium, Leucaena leucocephala, and Eucalyptus grandis. Litterbag technique was used and freshly fallen leaves of the species (equivalent to 100 g on a dry weight basis) were collected and placed into 30 cm × 45 cm nylon litterbags with a 2-mm mesh size. The weight of the samples in the litterbags was based on local plant litter application rates (5 t dry matter ha1) for maize production in the study location. There was a total of 216 litterbags (27 per species) for the study. Eight transects spaced at 1.0 m apart were laid in a randomized complete block design and twenty-seven litter bags spaced 0.5 m apart were placed on each transect. The litterbags were buried at 2 cm depth and three samples of each species were retrieved and weighed for 210 days to determine weight loss and nutrient release. Compared with Oxytenanthera abyssinica (8 weeks) and Senna siamea (6 weeks) half-life, rate of decomposition was analogous and higher than the other species. Further, Bambusa balcooa and the other non-bamboo species showed similar rate of decomposition. However, Bambusa vulgaris had marginally slower rate of decomposition compared to the traditional species. The highest rate of N, P, K and Ca release was recorded for Albizia lebbeck. Nonetheless, rates of P, Ca and Mg release were comparable to the other non-bamboo species. Eucalyptus grandis and Bambusa vulgaris also showed dominance in initial nitrogen and lignin concentrations and release. Therefore, with the observed substantial and comparable litter quality and decomposition rate among the species, it may be imperative to consider using the bamboo species for soil amendment and green manure in agroforestry system.