Introduction of grass-clover crops as biogas feedstock in cereal dominated crop rotations. Part I: Effects on soil organic carbon and food production

Changes of soil organic carbon (SOC) ontent can have a substantial effect on greenhouse gas emissions, but are rarely included in crop
production LCAs. SOC content strongly influences soil fertility and therefore crop yields, but is declining in many European soils. The present study investigated if integration of 1-2 years of grass-clover crops in a cereal-dominated crop rotation can increase the SOC pool and how this would impact food production. Results show that when grass-clover crops are integrated, the potential SOC content at steady state will be 41 to 52% higher than in the conventional cereal-dominated crop rotation. The net increase of wheat yields based on SOC improvements indicate that for a crop rotation with one year of grass-clover crops, the initial loss of food production can be counterbalanced due to the impact on fertility of the SOC increase.