A farm level approach to explore economic trade offs of soil organic carbon management in Scottish crop farms

This paper focuses on the economic trade-off space between effects on yield and input costs of management measures aimed at enhancing soil organic carbon (SOC) stocks to maintain soil fertility while providing important ecosystem services. An optimising dynamic farm level model, ScotFarm, was used to investigate the financial impacts of 4 SOC management measures (cover crops, zero tillage, minimum tillage and residue management) for three groups of Scottish crop farms. A sensitivity analysis was carried out to test the robustness of the model results on crop yields and costs of production for each measure. The results suggest that financially, tillage management is the only positive measure for Scottish farms at baseline levels of yield effects and input costs. Residue management is expected to have a negative impact on farm margins for the farms. The projected maximum positive financial impact was less than 10%. Results of the sensitivity analysis indicate that financial impacts of SOC management measures on farm margins are more sensitive to a change in crop yields than to changes in input costs. The findings point to further research needs with respect to the investigated trade-off space, and have implications for agricultural policy design aimed at enhancing SOC stocks under a changing climate.