Policy measures for sustainable sunflower cropping in EU-MED marginal lands amended by biochar: case study in Tuscany, Italy

摘要

The aim of this study is to evaluate economic support measures based on current EU policies affecting the profitability of large-scale deployment of biochar for sunflower cultivation in dry marginal lands in Italy, paving the way to large scale carbon sequestration in the EU Mediterranean region. Two cases were considered: i) straight biochar use and ii) biochar in combination with compost (COMBI: 20% biochar and 80% compost mass fraction), at application rates of 5 and 10 Mg ha(-1) respectively. Based on realistic estimations of achievable crop-yield performances by biochar and COMBI addition to dry soils, the effect of current policies on the economic viability of biochar deployment and farmers' income has been investigated. Using a cost-model we identified the required levels of support, in the form of (i) area subsidies for crop cultivation, (ii) tradable carbon certificates (credits), and (iii) REDII-compliant biofuel support for Aviation and Maritime, so to make biochar and sunflower cultivation in EU MED dry marginal lands competitive for sustainable crop-based biofuels. Results show that, by employing existing policy instruments, sufficient income can be generated for famers to recover marginal land, sequester large amount of carbon by BECCS at costs (similar to 82 (sic) Mg-1 of CO2) falling at or below the typical range of CCS measures, as well as offer additional environmental and socio-economic positive benefits. The combination of currently operational economic mechanisms from the Common Agricultural Policy, the Climate Policy, and the Renewable Energy Directive II can: i) maintain domestic farming activities, ii) support the implementation of biochar projects at local level, iii) contribute to achieve EU and national biofuel targets without generating ILUC impacts and iv) achieve unprecedent potential for carbon sequestration. However, prior to large-scale deployment, targeted on-site R&D actions aimed at validating biochar effects under local conditions (soil, climate, crops) are recommended, together with training and capacity building activities for local farmers.