Weed seed bank in agroforestry systems in the Central Amazon

Abstract

The objective of this study was to evaluate the seed bank collected in agro forestry systems. It was collected in each site, 20 soil samples from 0-5cm depth and three soil samples from 5-10 and 10-30cm depth with 15 X 15cm or 225cm². The seeds were sprouting for nine months in a greenhouse to identify the species and quantify the number of seeds. There were statistical differences on seed number between sites (Kruskal Wallis, 5%; p < 0,05) and it was found in average 7.236 seeds.m^-2 in 0-5cm depth, 2.159 seeds.m^-2 in 5-10cm depth and 448 seeds.m^-2 in 10-30cm depth. The plant species were basically herbaceous typical of agriculture lands. In agro forestry systems, practices of clearing can be recommended in combination with mulch and lively coverings as a way to control weed plants.