Influence of weed management strategies on soil seedbank diversity

The role of three weed management strategies on weed populations and community dynamics was investigated from 1989 to 1994. These were chemical weed control (CK), integrated weed control (IN) and mechanical weed control (ME). Weed populations and communities were analysed by univariate (species richness, rank: frequency diagrams) and multivariate (correspondence analysis) methods. Species richness of the soil seedbank differed with weed management strategies and over time, with an observed annual number of species that ranged from 18 to 32. The seedbank was dominated by the same pool of species in all cases, but these species responded differently among years and management strategies; their rank (relative abundance) and densities changed between strategy and within a strategy among the years. In the last 2 years of the study, the soil seedbank was characterized mainly by Capsella bursa-pastoris (L.) Medik on the ME strategy and Chenopodium album L. on the IN strategy. The CH strategy contrasted with the other two by the presence of a high density of Amaranthus retroflexus L.