Soil erosion is a world-wide phenomenon having a serious effect upon many agricultural soils. Until recently it was considered that erosion in Britain was limited to only a few susceptible soils in specific areas. However, the increasing monitoring of soils over the past 20 years has shown that water induced erosion is now a widespread and growing threat to farmland in many parts of Britain. This increase in the incidence of erosion can be directly related to changes that have taken place in agricultural practise in recent decades, with traditional mixed farming systems based on complex rotations being replaced by increasingly intensive and specialised cropping systems.