Soil carbon relations in Swedish agriculture : A GIS analysis and literature review of soil characteristics at farm level

Abstract: Carbon storage in agricultural soils is an important measure to mitigate climate change. As the soil management techniques can greatly influence the amount of carbon stored in agricultural soils, the influence of different managements was analyzed in a literature review for northern Europe and Sweden. With a unique dataset, the temporal development of soil organic matter, and in a case study the influence of SOM on crop yield in Sweden was examined, as well as the relationship of SOM towards clay content and pH level. For northern Europe, organic amendments in form of manure and sewage sludge application and crop residue incorporation as well as nitrogen fertilization and diverse crop rotations indicate a positive impact on soil organic carbon. The influence of reduced tillage was found to be less impactful. Detailed development of SOM in Swedish agricultural fields remains unclear due to data restraints and scarcity, but for the Skåne region the data analysis suggests a stable SOM content for the time period analyzed. The relationship of SOM to crop yield remains unclear but indicates that SOM can have a positive effect on crop yield. More research is needed to understand underlying mechanisms of development, management influence and yield response on soil organic carbon for northern Europe.