The rhizosphere represents one of the most complex ecosystems on earth with almost every root on the planet expected to have a chemically, physically and biologically unique rhizosphere. Despite its intrinsic complexity, understanding the rhizosphere is vital if we are to solve some of the world's most impending environmental crises such as sustainable food, fibre and energy production, preservation of water resources and biodiversity, and mitigation against climate change. One of the key challenges that faces rhizosphere ecologists is how to translate their fundamental research into practical real-world applications. In addition, they need to convince policy makers that consideration of the rhizosphere is vital in the formulation and implementation of any environmental policy relating to plant growth. This is highlighted by the recent biofuel and carbon debt debate whereby rhizosphere processes such as priming were largely ignored leading to destabilization of national policies. Recent advances in our understanding of the tangled web of rhizosphere interactions have been largely driven by technological innovations in analytical, bioinformatic and imaging tools, and this is likely to continue for the foreseeable future. However, there is also a critical need to incorporate this more reductionist information into mathematical models that are capable of incorporating the rhizosphere to allow simulation of plot- or landscape-level processes that are particularly relevant to policymakers. Consequently, as the multidisciplinary rhizosphere science community grows, there will be increasing need to both integrate scientific information and to subsequently convey this in an effective manner to stakeholders. If we can achieve this we will be in a good position to help prevent ongoing global environmental degeneration. These issues were addressed at the RHIZOSPHERE 2 International Conference which was held at Montpellier, France in August 2007. This special issue gathers some of the research presented during this major event.