European biofuel policy has been dominated by discussions about the indirect effects of biofuel consumption, and in particular indirect land use change and impacts on food prices and security. One widely considered option to reduce or avoid these risks is to move towards second-generation biofuels from cellulosic feedstocks. Biofuels produced from cellulosic energy crops could deliver high greenhouse gas savings and deliver other environmental benefits if produced sustainably, but on the other hand could lead to environmental damage if energy crops displace food production on agricultural land or negatively impact carbon stocks and biodiversity on undisturbed forest and grassland. With this research, we seek to identify and describe the opportunity for sustainable energy cropping through field work and literature review, including case studies of early energy crop projects in Europe.
In the first case study, we visited three sites in the Carbonia region of Sardinia, Italy, where Biochemtex is conducting trials of Arundo donax (giant reed) on low-productivity, underutilized agricultural land. Our cursory assessment did not raise specific concerns of biodiversity impacts, soil carbon or water availability, and it was clear that the energy crop would increase carbon stocks and productivity in this region. The project plan also includes using A. donax to remediate industrial land contaminated with heavy metals that is currently unfit for other crops. Overall, we conclude that the Biochemtex project has the potential to deliver some environmental benefits, while posing little risk to soil carbon stocks, water use, or displacement of other crops.
The second case study we examined is a project in the Pelagonia region of Macedonia, led by Ethanol Europe in collaboration with DuPont and NexSteppe. Biomass sorghum and switchgrass are currently being tested on actively used agricultural land as well as arid, abandoned agricultural land. During our site visit, we witnessed challenges in project implementation in this first year of trials. There seem to be real opportunities for both the use of abandoned land and for the introduction of double cropping on the actively used land, but it is not yet possible to be confident that commercially viable yields can be achieved without environmental impact or displacing food production.
Through literature review we also investigated a rather different type of energy crop system that could potentially deliver associated environmental benefits. ‘Paludiculture,’ the wet cultivation of peatlands, could be used to produce biomass for energy while actively rehabilitating degraded peatlands in Europe, sequestering soil carbon and supporting native plant and animal species. Paludiculture is still in the early stages of adoption, and challenges remain for more sustainable harvesting technologies and economic viability of projects – but in cases where there is an economic case for biomass production, paludiculture could deliver a win-win-win for climate mitigation, wildlife conservation, and renewable energy.
Through on-the-ground verification, this report supports much of what is shown in the literature – that there is a real potential to cultivate energy crops sustainably with little environmental risk, and in some cases while delivering substantial direct environmental benefits other than renewable energy production. At the same time, we highlight challenges in the implementation of energy crop projects and hurdles that must be overcome before sustainability can be assured.