Comparison of methods for mapping rhizosphere processes in the context of their surrounding root and soil environments.

The rhizosphere embodies a complex biogeochemical zone with enhanced rates of nutrient exchange between plants, soil, and microbial communities. Understanding controls on rhizosphere dynamics is critical to support emerging concepts including rhizosphere engineering and reduced dependence on chemical fertilizers which have direct application to food production, increased biofuel generation, and habitat restoration efforts. Yet, its fine spatial scale and complex interactions between geochemical and microbial processes within complex spatiotemporal gradients make the rhizosphere notoriously difficult to study. Emerging instrumentation and methodologies, however, are providing improved resolution to rhizosphere measurements and helping to address critical knowledge gaps in rhizosphere function, ecology, and establishment. Here, we examine recent advances in analysis techniques and the resulting potential for improved understanding of rhizosphere function.