Modelling at the micro scale will provide a mechanistic understanding of the fundamental biogeochemical processes in soil and outputs will improve our ability to find bulk responses suitable for use at the continuum scale. Models at these larger scales will be validated using RRes and NWRes plot and field experiments. The modelling will also drive understanding and provide predictive capabilities for water flow and water quality from the NWRes and RRes plot and field scale experiments we require a tailored suite of flow and transport models. These will account for water flow, solute and particle transport and will be applied to both N and P transfer and will be coupled with a model for gaseous diffusion, accounting for the temporal variation of the air-water-solute status of the soil and drive studies of nitrous oxide emissions from the experimental sites. We also need to be able to understand how to up and down scale knowledge of the behaviour of soil for use in models that operate from the mm to the global scales. We shall test the hypotheses that mechanistic understanding of soil rhizosphere processes can be effectively captured to yield bulk functional relationships between soil variables essential for the implementation of continuum scale (plot and field) models and integrated descriptions of land, air and water processes will increase our predictive capabilities, especially with respect to air and water quality.