Interpretation of bioassays in the study of interactions between soil organisms and plants: involvement of nutrient factors

摘要: Summary • Increased plant growth in sterilized soil is usually ascribed to the elimination of (often unidentified) soil-borne pathogens. Plant–soil bioassays are reported here for three dune soils and two species (Ammophila arenaria Carex arenaria). • Dynamics growth, availability uptake nutrients were compared (25 kGy gamma-irradiation) vs control soils. • Plant acquisition nutrients, example P, even when provided apparent excess, significantly enhanced gamma-irradiated calcareous sands. With A. arenaria, positive sterilization effect occurred independently initial dry mass. The addition extracts planted growing unsterilized sand caused an increase root that could not be related either or pathogens. • Increased may contribute nonsterile : sterile ratios are < 1. Any ecological speculation involving role biological factors should based on fully validated plant–soil bioassays, which account nutritional other nonpathogen-related side-effects induced by sterilization.