what is rhizosphere effect

The rhizosphere effect describes the changes in microbial activity and population density in soil due to the influence of plant roots. It generally results in a several-fold increase in microbial biomass compared to non-rhizosphere (bulk) soil. This effect is driven by root exudates that serve as energy sources for microbes. It enhances microbial-mediated processes such as nitrogen fixation, phosphorus solubilization, and organic matter decomposition. The effect can vary depending on plant species, soil type, and environmental conditions.