Soil parameter variability affecting simulated field-scale water balance, erosion and phosphorus losses

Field-scale modelling is widely used as a means to look into interdependencies of processes and to assess potential effects of agricultural management practices as well as of climate and socio-economic scenarios. Generalisation from field-scale results to cover all agricultural land in a catchment by using typical soil-crop-slope combinations has been restricted by a lack of information for the systematic parameterisation of soils. Data from single experimental fields are seldom representative for the whole respective catchment. In this study typical soil profiles for mineral agricultural soils in Finland are defined. Key parameters describing e.g. the texture and water holding capacity of soils, were generated from existing soil data using expert knowledge and are aimed to be used for field-scale modelling when the target is not to model a particular field but soils of certain type in general. Estimates for water balance and phosphorus losses, obtained with the ICECREAM model by applying these data sets, were realistic and compatible with experimental results measured in Finland.