Litter Production and Nutrients Return of a Taxi-Branco Stand and of a Secondary Forest in Amapá

Abstract

This study aimed to evaluate the total and seasonal deposition of biomass, concentration and total amount of nutrient in litter of a taxi-branco stand and of a secondary forest, both 9 years old and established in area deforested by shifting cultivation. Thirty collectors 1.5 m2 were distributed (20 at taxi-branco and ten at secondary forest). Litter was collected monthly, oven-dried and analyzed for concentrations of N, P, K, Ca and Mg. The annual deposition of litter was 9646 kg/ha in taxi-branco stand and 4474 kg/ha in secondary forest. Litter production was greater in the lower precipitation period (August to November), comprising 74% and 56% of the annual production of the taxi-branco stand and secondary forest, respectively. Taxi-branco litter had higher concentration of N, while the secondary forest had higher concentration of Ca, Mg, K and P. The annual transfer of N was greater in taxi-branco stand (117.0 kg/ha) than in secondary forest (51.4 kg/ha); Ca was greater in the secondary forest (41.3 kg/ha) than in taxi-branco (26.4 kg/ha); and Mg, K and P were similar in two areas. Soils recovery in the migrant agriculture should be more effective in taxi-branco enriched secondary forests, by the species association with different characteristics from litter production, N fixation and nutrients cycling.