Organic matter dynamics in coarse sandy calcareous soils

The decomposition of organic matter in coarse sandy calcareous soils (beach sand) is thought to be much higher than in acid fine sandy soils but relatively little research is performed on these soils. Laboratory incubation experiments in which the release of soil carbon (C) is determined may overestimate the release of the soil organic C, as part of the measured C may have been released from the soil carbonates. In addition, it is not clear if the contribution of organic applications to the soil organic matter is also lower on these soils compared to acid fine sandy soils. This study focuses on 1: whether the d13C signature of organic carbon differs from that of the carbonate carbon and therefore could be used to determine C-mineralization of coarse sandy calcareous soils and 2: whether and to what extent applications of domestic compost and solid cow manure or combinations of both are able to improve organic matter content and its effects on the production of ornamentals.