The growing bioeconomy will require a greater supply of biomass in the future for both bioenergy and bio-based products. Today, many bioenergy cropping systems (BCS) are suboptimal due to either social-ecological threats or technical limitations. In addition, the competition for land between bioenergy-crop cultivation, food-crop cultivation, and biodiversity conservation is expected to increase as a result of both continuous world population growth and expected severe climate change effects. This study investigates how BCS can become more social-ecologically sustainable in future. It brings together expert opinions from the fields of agronomy, economics, meteorology, and geography. Potential solutions to the following five main requirements for a more holistically sustainable supply of biomass are summarized: (i) bioenergy-crop cultivation should provide a beneficial social-ecological contribution, such as an increase in both biodiversity and landscape aesthetics, (ii) bioenergy crops should be cultivated on marginal agricultural land so as not to compete with food-crop production, (iii) BCS need to be resilient in the face of projected severe climate change effects, (iv) BCS should foster rural development and support the vast number of small-scale family farmers, managing about 80% of agricultural land and natural resources globally, and (v) bioenergy-crop cultivation must be planned and implemented systematically, using holistic approaches. Further research activities and policy incentives should not only consider the economic potential of bioenergy-crop cultivation, but also aspects of biodiversity, soil fertility, and climate change adaptation specific to site conditions and the given social context. This will help to adapt existing agricultural systems in a changing world and foster the development of a more social-ecologically sustainable bioeconomy.

Demand for sustainably produced biomass is expected to increase with the need to provide renewable commodities, improve resource security and reduce greenhouse gas emissions in line with COP26 commitments. Studies have demonstrated additional environmental benefits of using perennial biomass crops (PBCs), when produced appropriately, as a feedstock for the growing bioeconomy, including utilisation for bioenergy (with or without carbon capture and storage). PBCs can potentially contribute to Common Agricultural Policy (CAP) (2023–27) objectives provided they are carefully integrated into farming systems and landscapes. Despite significant research and development (R&D) investment over decades in herbaceous and coppiced woody PBCs, deployment has largely stagnated due to social, economic and policy uncertainties. This paper identifies the challenges in creating policies that are acceptable to all actors. Development will need to be informed by measurement, reporting and verification (MRV) of greenhouse gas emissions reductions and other environmental, economic and social metrics. It discusses interlinked issues that must be considered in the expansion of PBC production: (i) available land; (ii) yield potential; (iii) integration into farming systems; (iv) R&D requirements; (v) utilisation options; and (vi) market systems and the socio‐economic environment. It makes policy recommendations that would enable greater PBC deployment: (1) incentivise farmers and land managers through specific policy measures, including carbon pricing, to allocate their less productive and less profitable land for uses which deliver demonstrable greenhouse gas reductions; (2) enable greenhouse gas mitigation markets to develop and offer secure contracts for commercial developers of verifiable low‐carbon bioenergy and bioproducts; (3) support innovation in biomass utilisation value chains; and (4) continue long‐term, strategic R&D and education for positive environmental, economic and social sustainability impacts.

Miscanthus, a C4 perennial rhizomatous grass from Asia is a leading candidate for the supply of sustainable biomass needed to grow the bioeconomy. European Miscanthus breeding programmes have recently produced a new range of seeded hybrids with the objective of increasing scalability to large acreages limited by current clonal propagation. For the EU‐GRACE project, new replicated field trials were established in seven locations across Europe in 2018 with eight intraspecific M. sinensis hybrids (sin × sin) and six M. sacchariflorus × M. sinensis (sac × sin) from Dutch and UK breeding programmes, respectively, with clonal Miscanthus × giganteus. The planting density of the sin × sin was double that of sac × sin (30,000 & 15,000 plants ha⁻¹), creating commercially relevant upscaling comparisons between systems. Over the first 3 years, the establishment depended on location and hybrid. The mature sin × sin hybrids formed tight tufts of shoots up to 2.5 m tall which flower and senesce earlier than the taller sac × sin hybrids. Following the third growing season, the highest yields were recorded in Northern Italy at a low altitude (average 13.7 (max 21) Mg DM ha⁻¹) and the lowest yielding was on the industrially damaged marginal land site in Northern France (average 7.0 (max 10) Mg DM ha⁻¹). Moisture contents at spring harvest were lowest in Croatia (21.7%) and highest in Wales, UK (41.6%). Overall, lower moisture contents at harvest, which are highly desirable for transport, storage and for most end‐use applications, were found in sin × sin hybrids than sac × sin (30% and 40%, respectively). Yield depended on climate interactions with the hybrid and their associated planting systems. The sin × sin hybrids appeared better adapted to northern Europe and sac × sin hybrids to southern Europe. Longer‐term yield observations over crop lifespans will be needed to explore the biological (yield persistence) and economic costs and benefits of the different hybrid systems.

Miscanthus, a C₄ perennial rhizomatous grass, is capable of growing in varied climates and soil types in Europe, including on marginal lands. It can produce high yields with low nutrient inputs when harvested after complete senescence. Senescence induction and rate depend on complex genetic, environmental, and management interactions. To explore these interactions, we analysed four miscanthus hybrids (two novel seed‐based hybrids, GRC 3 [Miscanthus sinensis × sinensis] and GRC 14 [M. sacchariflorus × sinensis]; GRC 15, a novel M. sacchariflorus × sinensis clone; and GRC 9, a standard Miscanthus × giganteus clone) in Italy, Croatia, Germany and the UK. Over all trial locations and hybrids, the average aboveground biomass of the 3‐year‐old stands in August 2020 was 15 t DM ha⁻¹ with nutrient contents of 7.6 mg N g⁻¹ and 14.6 mg K g⁻¹. As expected, delaying the harvest until spring reduced overall yield and nutrient contents (12 t DM ha⁻¹, 3.3 mg N g⁻¹, and 5.5 mg K g⁻¹). At lower latitudes, the late‐ripening M. sacchariflorus × sinensis GRC 14 and GRC 15 combined high yields with low nutrient contents. At the most elevated latitude location (UK), the early‐ripening M. sinensis × sinensis combined high biomass yields with low nutrient offtakes. The clonal Miscanthus × giganteus with intermediate flowering and senescence attained similar low nutrient contents by spring harvest at all four locations. Seasonal changes in yield and nutrient levels analysed in this study provide: (1) a first step towards recommending hybrids for specific locations and end uses in Europe; (2) crucial data for determination of harvest time and practical steps in the valorization of biomass; and (3) key sustainability data for life cycle assessments. Identification of trade‐offs resulting from genetic × environment × management interactions is critical for increasing sustainable biomass supply from miscanthus grown on marginal lands.

New biomass crop hybrids for bioeconomic expansion require yield projections to determine their potential for strategic land use planning in the face of global challenges. Our biomass growth simulation incorporates radiation interception and conversion efficiency. Models often use leaf area to predict interception which is demanding to determine accurately, so instead we use low‐cost rapid light interception measurements using a simple laboratory‐made line ceptometer and relate the dynamics of canopy closure to thermal time, and to measurements of biomass. We apply the model to project the European biomass potentials of new market‐ready hybrids for 2020–2030. Field measurements are easier to collect, the calibration is seasonally dynamic and reduces influence of weather variation between field sites. The model obtained is conservative, being calibrated by crops of varying establishment and varying maturity on less productive (marginal) land. This results in conservative projections of miscanthus hybrids for 2020–2030 based on 10% land use conversion of the least (productive) grassland and arable for farm diversification, which show a European potential of 80.7–89.7 Mt year⁻¹ biomass, with potential for 1.2–1.3 EJ year⁻¹ energy and 36.3–40.3 Mt year⁻¹ carbon capture, with seeded Miscanthus sacchariflorus × sinensis displaying highest yield potential. Simulated biomass projections must be viewed in light of the field measurements on less productive land with high soil water deficits. We are attempting to model the results from an ambitious and novel project combining new hybrids across Europe with agronomy which has not been perfected on less productive sites. Nevertheless, at the time of energy sourcing issues, seed‐propagated miscanthus hybrids for the upscaled provision of bioenergy offer an alternative source of renewable energy. If European countries provide incentives for growers to invest, seeded hybrids can improve product availability and biomass yields over the current commercial miscanthus variety.

This study reviews a variety of “bioeconomy approaches” (BAs) to assess their potential contribution to resilience in agricultural systems, focusing on benefits that can improve multi‐functionality regarding private and public goods. It is based on Meuwissen et al.'s framework to assess the resilience of farming systems. Drawing on literature and expert knowledge, this indicator framework is adapted to develop a new framework which is then applied to seven contrasting BAs (miscanthus, perennial flowering wild plant mixtures, permanent grassland, nutrient recycling, agrivoltaics, urban agriculture, and microalgae). The major outcomes are: 1) the extended indicator framework can help evaluate BAs for their potential to foster resilience in future agricultural systems, 2) all BAs are characterized by their ability to provide multiple private and public goods simultaneously, 3) the strongest contribution of BAs to public goods is their function in maintaining the good condition of natural resources and resource‐use efficiency, 4) all BAs can enhance resilience in agricultural systems by contributing diversity, multifunctionality, environmental sustainability, and autonomy, 5) the mitigation of potential drawbacks of BAs implementation requires ex‐ante assessment, favorable BAs combinations, and stakeholder involvement, 6) context‐specific analysis of each BAs is required to assess their qualitative and quantitative contribution to resilience.