Potential of timbo (Ateleia glazioveana) and marica (Mimosa bimucronata) for green manure production on subtropical zones. II: decomposition and quality

摘要

The purpose of this study was to know the general decomposition of timbo and marica green biomass (leaves and twigs, separately). Litterbags were assembled with biomass (50 g for leaves and 60 g for twigs) and randomised on soil surface. Periodicityof each biomass fraction sampling was two and four months, for leaves and twigs respectively. Dry matter, carbon, macronutrients, lignin and phenols were analysed to determine over-time decomposition. Timbo patterns were relatively slow, liberating about 35 percent of dry matter and 31 percent of cumulative nitrogen after two months. However, leaves and twigs presents some synchronicity on mineralization. This factor makes its estimation easy to be used simultaneously. Timbo species were considered potentially adequate for supplying organic matter and nitrogen for cropping with medium or perennial rotations. Marica lost about 29 percent and 37 percent of dry matter and 19 percent and 13 percent of nitrogen, for leaves and twigs respectively. Its biomass fractions presented different patterns of decomposition. This factor limits simultaneous use for green manure. However, this species can be useful for soil restoration systems.