Gradients in the rhizosphere Longitudinal lateral gradients important for plant nutrition: Nutrient concentration H Redox potential -especially in waterlogged soils Exudates concentrations composition 2 Microbial activity]-population density composition Non-infecting rhizosphere microorganisms -especially soil bacteria Infecting rhizosphere microorganisms:-especially mycorrhizal fungiGradients in the rhizosphere Longitudinal & lateral gradients important for plant nutrition: - concentrations & composition - population density & composition - especially in waterlogged soils - especially soil bacteria - especially mycorrhizal fungi