Organic Matter in the soils of Europe: Present status and future trends

The need for accurate information on the organic matter (OM) content in soils at European, National or Regional level has been increasing steadily over the past few years. This is a result of increasing concern about environmental problems such as soil degradation, desertification (CEC, 1992; UNEP, 1991), erosion and, at the worldwide level, the impact of climate change. There is some evidence to suggest that the OM content of soils in Europe is decreasing, in some cases at an alarming rate, and yet OM is vital to sustain many soil functions. For example, a decline in OM content is accompanied by a decrease in fertility and loss of structure that together exacerbate overall soil degradation. There are many factors responsible for the decline in soil OM and many of them stem from human activity, for example: Conversion of grassland, forests and natural vegetation to arable land; Deep ploughing of arable soils causing rapid mineralisation of organic matter, particularly Humus; Overgrazing; Soil erosion; Forest fires. The main objective at present is to identify and secure an existing information base for organic matter (OM) contents of European soils at time T0, i.e. to define a ‘background or reference level’. Effectively this means compiling and analysing data on the organic carbon (OC) content because in most cases this is the parameter that is measured. The next objective is to establish the future trend in soil OM contents with a view to developing more sustainable systems of land management and avoiding or reducing further losses. This paper attempts to summarize briefly existing knowledge about the OM content in the soils at European level. Same examples of the knowledge base, the improvements that are needed and possible trends in soil OM content at regional level are given.