The rhizosphere: soil factors Width not to scale Layer of soil surrounding the Root→·tSol growing root that is affected B the root Epidermal and cortical cells lysed and invaded Usually a few mm, up to say 1 bacteria cm (no sharp boundary EXtent depends on soil properties, e. g 鬆- Micro-organisms with microbial an d pH buffering plant mucilages spreading into the soi-Sorption capacity Nutrient supply rate Sloughed root cap cells Microbial populations Root cap Decomposition of exudates RoviraThe rhizosphere: soil factors Rovira 1960? • Layer of soil surrounding the growing root that is affected by the root • Usually a few mm, up to say 1 cm (no sharp boundary) • Extent depends on soil properties; e.g. - pH & buffering - Sorption capacity - Nutrient supply rate - Microbial populations - Decomposition of exudates Width not to scale