MATERIAL BALANCES OF AGRICULTURAL SOIL - A METHOD FOR EARLY RECOGNITION OF SOIL ALTERATIONS

For agricultural soils of a lowland region in Switzerland the input and output of the elements nitrogen, phosphorus, copper, zinc, cadmium and lead were measured over two years. In spite of the fact that the emission standards are met there is a slow and steady increase of the P, Cu, Zn and Pb concentrations found in the plough layer. In accordance with the principle of prevention the metabolism of the soil should be controlled on a large scale in such a way that this concentration increase can be substantially reduced within decades. With the available analytical methods the observed concentration increases in the soil are clearly detectable only after decades. Regional annual material balancing of the relevant anthropogenic processes (farming, private households, industry and trade), however, allows early detection of small changes in concentration. Consequently, a soil protection strategy which obeys the principle of early prevention should be completed by regional material balances.