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In EU-25, most soils are out of equilibrium as regards soil organic matter contents, as they have been affected by land management practices and land use (Smith et al., 2005). JRC ISPRA has compiled a soil organic matter map for Europe. Whether the information in the European soil map is up to date remains uncertain as very few national monitoring programs of soil organic matter exist. Assessments of changes in soil organic matter suggest that in cropland soil carbon stocks in general continue to decline perhaps as a result of recent land use change or agricultural management, e.g. tillage practices or manure use (Smith et al., 2005; Vleeshouwers and Verhagen, 2002; Freibauer et al., 2004). The values for cropland soil carbon loss however are highly uncertain (Janssens et al., 2003). Losses of soil carbon have been associated with changes in land use, soil cultivation and climate change. Recent papers speculate on the potential risk for loss of functions in soil that is associated with loss of organic matter from soil (Lal et al., 2004). Bellamy et al. (2005) report on the bases of a recent repeated monitoring of soil organic matter in the UK that the organic matter content in all categories of land use has decreased. Davidson and Janssens (2006) review the impact of temperature on sensitivity of soil organic matter to decomposition. A relation of decomposition with temperature could make soil organic matter in warmer regions in Europe more sensitive to decline. Jones et al. (2005) calculated that 0.6% of soil carbon in European terrestrial ecosystems is lost annually. Leifeld et al (2003) and Arrouays et al. (2003) report on changes in carbon stocks in other European countries. A political context for agricultural greenhouse gas mitigation arises from the Kyoto Protocol to the 1992 United Nations Framework Convention on Climate Change (UNFCCC) and its subsequent elaboration to the Marrakech Accords. This accord allows countries to include biospheric carbon sinks and sources in attempts to meet the Reduction Commitments for the first commitment period 2008 – 2012 through forest, grazing and cropland management and re-vegetation. The EU-soil strategy is in line with this policy; it calls for optimizing soil organic matter and maintaining soil quality. Across Europe very few countries have designed and implemented monitoring networks for soil organic matter. In many countries measures on soil organic matter are taken by farmers and relate to productivity and fertilizer recommendations. These measurements do differ with respect to depth, frequency and across categories of land use. Furthermore, crucial information on e.g. bulk density may not be available. The absence of such monitoring and data makes it very difficult for European countries to engage with soil management in the Kyoto Protocol obligations. JRC ISPRA has recently suggested a monitoring strategy for organic matter in soils across Europe (Stolbovoy et al., 2005).
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