Search

Highlights • 105 farmers were asked to plan for increasing carbon storage on their fields. • The plans were evaluated through expert panel and simplified carbon balance modeling. • Farmers chose methods with co-benefits to soil productivity and yield. • Most plans were suitable for research and show potential for C-sequestration. Soil carbon sequestration is a recognized climate mitigation method, but it involves changes in the practices of more than 0.5 billion farms worldwide. Regionally customized carbon-farming programs are one way to tailor soil carbon storage to local conditions. We conducted farmer participatory research on 105 Finnish farms to investigate how farmers approach carbon (C) sequestration. We conducted training for farmers in the basics of carbon-farming and instructed them to make a Carbon Farming Plan for one of their fields. The plans were evaluated by a team of experts and through soil C balance calculations. In addition, potential nutrient limitations and the existing C stock were identified from soil tests. Although the existing C stocks were relatively high, an assessment of the plans indicated high potential for additional C storage (median 320 kg C ha−1year−1). The plans did not show any sensitivity to the existing C stock, with similar C inputs planned for low organic matter (OM) and high OM soils. The farmers either did not know their C stock or were not familiar with the C balance concept. Most soil samples showed considerable nutrient deficiencies (P, S, B and Mn), which can limit C storage. The quality of most plans was adequate for research with minor modifications. The largest C storage potential was estimated for measures with large additions of nutrient-poor amendments or in grazing. Most farmers chose measures with relatively low C storage benefits but high potential benefits for soil structure and productivity (cover crops, nutrient-rich amendments, grassland management). The C gain from some measures (subsoiling, diversity in grasslands) could not be estimated with current methodologies. The magnitude of planned C storage over 5 years on most farms was so small (

A growing amount of construction and demolition waste (C&DW) is produced in Europe each year. Increased recycling of C&DW is required by the EU Waste Framework Directive, targeting at 70% recycling of non-hazardous C&DW by 2020. The aim of the study was to assess the performance of the common Finnish C&DW management system against this target, thus identifying the environmental and economic impacts of the system and the effects brought about by changes in the waste composition. In this study, a combination of different methodologies was applied to evaluate holistically the performance of the C&DW management system: material flow analysis (MFA) was employed to assess material and energy recovery rates, life cycle assessment (LCA) was utilised to evaluate climate change impacts, and environmental life cycle costing (ELCC) was used for measuring the costs. In addition, the applicability of the best available technology (BAT) approach for developing the efficiency of the waste management system was scrutinised. Thus, aligned with the empirical aim of assessing the performance of Finnish C&DW in reference to the EU Waste Framework Directive, the theoretical aim of the study was to test how the employment of different assessment methodologies affects the performance results of the C&DW management system.According to the results, the overall system produced environmental benefits and was economically profitable, but was far behind the target of recycling 70%. Based on the assessments, the EU Waste Framework Directive target will not be achieved, even with the likely changes in waste composition. Thus, major changes will be needed to source separation and recovery within the system, e.g. by finding recycling concepts for waste wood without decreasing the environmental and economic benefits of the system. The employment of different methodologies gave a diversified view of the possibilities to develop the system. The metal treatment performed well in all assessments; hence improvements to it would not benefit the system notably. For wood the results were controversial, since the energy recovery generated environmental and economic benefits, but did not increase the recycling rate. Material recovery concepts should be developed, but simultaneously the environmental and economic benefits should be retained. Miscellaneous waste had the potential for increasing recycling and avoiding costs and emissions. Mixed waste was identified as the worst fraction in relation to climate change impacts, costs and material recycling. Applying the BAT approach showed that BAT for waste management needs to be based on system-level rather than installation-level assessments.This multi-methodological assessment of C&DW management showed the need for analysing the environmental performance of a system from different perspectives before decision-making. In general, the recycling of waste generates greater environmental benefits than energy recovery, but this may not always be the case. Regional differences in operations and waste composition may support arguments for differing recycling targets in different regions.