SIDASS project: Part 5: Prediction of mechanical strength of arable soils and its effects on physical properties at various map scales

A model to predict the mechanical strength of arable soils and its effect on physical properties was developed and integrated within the framework of the SIDASS-project “A spatially distributed simulation model predicting the dynamics of agro-physical soil state within Eastern and Western Europe countries for the selection of management practices to prevent soil erosion based on sustainable soil–water interactions”. chanical strength quantification of agricultural or forest soils in order to assess the trafficability or the limitation of mechanical loading at given soil properties are presented. While agricultural engineering approaches are primarily restricted to the definition of stress distribution in relation to machine and tire type, soil scientists try to include in their approach, not only the mechanical strength properties of the soil horizons but also the inter-dependence of the hydraulic and mechanical strength properties. Soil scientists also understand soil genetical processes and are able to predict the consequences of stress applications for current and future soil physical properties. Thus, the present paper analyses the possibilities for applying pedotransfer functions that relate precompression stresses, as measures of soil strength at various scales, to stress effects on physical soil parameters, such as air permeability. It has been proven that multiregression equations can be used to calculate precompression stresses when they are based on physical properties like texture, aggregation, water retention properties, mechanical parameters like cohesion and angle of the internal friction values. This determination can be carried out and applied at various scales. Examples are presented from the 1:1,000,000 soil map for Europe up to the field or farm level (1:5000) as a very detailed scale. ethod affords the separation of different sensitivity levels of stress application and consequences for a sustainable site management in the future. The proposed method is a useful tool towards fulfilling soil protection laws in Europe in the same way, as it can be used as a decision maker at the local farm level, both with respect to site-specific management strategies and for the machine industry for the development of regions and climate-dependent machinery. It can be also used as an index for landuse restrictions or to define non site-adjusted landuse techniques.