The potential for soil phosphorus tests to predict phosphorus losses in overland flow

摘要

Soil phosphorus tests offer a potentially powerful tool for land managers trying to predict the areas which will contribute diffuse losses of phosphorus (P) to surface water bodies through the overland flow vector - but do they work? We address this question at a range of scales, from patch (< 1 m(2)), through plot (several m(2)) to small watershed (several hectares). Our hypothesis is that as we increase the scale, and therefore the complexity of the system, soil P tests will predict P concentrations and losses associated with overland flow less well, and that this is partly due to a shift from dissolved P losses to P losses associated with eroded soil material.