Tackling climate change remains a critical challenge for society. Achieving climate neutrality requires a massive expansion of renewable energies such as wind and photovoltaics (PV). Agriculture plays a key role in this context, especially as the expansion of ground-mounted PV systems often leads to land-use conflicts. Agrivoltaics (AV), which combines agricultural and electricity production, can be a solution, but the synergies are particularly dependent on local agronomic conditions. There is also a knowledge gap in how AV expansion impacts greenhouse gas (GHG) emissions at the landscape level and how it contributes to regional emission reduction targets. In this study, we analysed the economic and climate change mitigation impacts of AV expansion pathways in the German state Baden-Württemberg using an integrated land use model and life cycle assessment under the assumption of general rentability of electricity production by AV. We found that implementing AV on 1%-5% of the regions's arable and grassland area reduced the total agricultural gross margin by a maximum of approximately 0.5%. Concurrently, AV implementation reduced GHG emissions by about 1.2 million to 5.9 million metric tons of CO₂ equivalent (Mt CO₂-eq). Even if this reduction is almost exclusively accounted for in the energy sector, in absolute terms it amounts to more than the current GHG emissions from Baden-Württemberg's agricultural sector (about 4.4 Mt CO₂-eq in 2021). In the 5% expansion scenario, almost 90% of the installations were installed on grassland, but this share dropped to 72% when considering landscape quality constraints. Although we found considerable regional disparity, our findings still suggest that AV is an essential component for regional emission reduction targets. These results are particularly relevant for policymakers in spatial planning, agricultural and energy policy.

Germany (DE) and China (CN) have different political approaches in supporting the biogas sector. Three German and three Chinese large-scale biogas plants (BGPs) were evaluated as part of a year-round monitoring program. Laboratory methods were utilized to analyze the chemical indicators. Results showed a stable anaerobic digestion process without system failures in all BGPs. The methane yield had a range of 0.23–0.35 m³_CH4/kg_ODM for DE BGPs and 0.11–0.22 m³_CH4/kg_ODM for CN BGPs, due to different substrates and working temperatures. Financial analyses indicated that DE BGPs are viable under their current feed-in tariffs contracts. Their financial internal rate of return (IRR) ranged between 8 and 22%. However, all CN BGPs had negative IRRs, indicating that they are financially unfeasible. Risk analyses illustrated that DE BGPs will face financial nonviability if benefits decrease by 9–33% or costs increase by 10–49%, or if a combined worse case (benefit decrease and cost increase) of 5–20% occurs. Incentives to BGP operations are particularly important in China, where the government should consider switching the construction-based subsidy to a performance-based subsidy system to motivate the operators. BGP monitoring is necessary to understand the performance, in addition to briefing policymakers in case a policy reform is needed.

Photovoltaics and wind energy must be considerably expanded to achieve the targeted climate neutrality in Germany in 2045 which may cause new conflicts. Especially ground-mounted photovoltaic systems, which are often associated with a high land consumption rate, conflict with other land uses such as agriculture. Due to the simultaneous electricity generation and agricultural use, agrivoltaics (AV) systems can increase land use efficiency which is why they are in the political focus. In this study, we go beyond the limited point-wise analyses of previous studies which have focused mainly on the technology itself and potential yield changes of individual crops and provide a spatially explicit analysis of the AV potential. This is done by an in-depth analysis on the example of arable land in the Stuttgart Region, one of the most important conurbations in Germany and Europe. The study focusses on the resulting agronomic effects in the region and the associated agro-economic effects. The analysis is carried out with an integrated land use model that optimises arable land use by maximising gross margins at the farm level. Legal framework conditions such as the regional plan are considered constraints, and existing studies on yield effects under AV are used. The results show that there are synergies through increases in the agricultural gross margins. These synergies could be realized on about 3% of arable land in the study region subject to the underlying assumptions made. With more than 10% of the arable land in the study region used for AV, the average gross margins in arable farming decrease by about 280 € per ha of AV. Farms or areas with a high share of special crops, such as strawberries, demonstrate the highest profitability. On the other hand, regions with a high share of root crops in the crop rotation seem to be less favourable to establish AV. This demonstrates that, the agricultural land use structure must be considered in the holistic assessment of the land use efficiency of AV installations. Our results help policymakers better assess the effects of AV on land use and are useful for identifying priority implementation areas, for instance, in regional or land use plans.

Agriculture accounts for a large proportion of global greenhouse gas (GHG) emissions. It is therefore crucial to identify effective and efficient GHG mitigation potentials in agriculture, but also in related upstream sectors. However, previous studies in this area have rarely undertaken a cross-sectoral assessment. There is also a gap in research on the GHG mitigation potential of innovations such as green ammonia in arable farming at a larger spatial scale. The study therefore aimed to analyze how selected technological adaptations or innovations can be used to contribute to efficient and effective cross-sectoral GHG mitigation in conventional arable farming systems. Germany, one of the largest agricultural producers and contributors of GHG emissions from agriculture in the EU, was chosen as a case study. The GHG mitigation potential and abatement cost of four selected measures were analyzed using an integrated land use model and life cycle assessment. Their GHG mitigation potential varied between 0.3 Mt CO₂-eq. for nitrification inhibitors under lower mitigation rate assumptions and 4.7 Mt CO₂-eq. for green ammonia with upper mitigation rate assumptions on GHG emission impacts, i. e. rather high mitigation. While crop varieties based on new genomic technologies (NGT) were introduced at no GHG abatement cost, the average mitigation costs ranged from 48 € for the use of nitrification inhibitors (upper mitigation rate) to 1233 € per t CO₂-eq. for N sensors (lower mitigation rate). There were also regional differences due to different land use structures, regional farm sizes, economic and agronomic conditions. Based on these results we recommend for agricultural and environmental policy to foster the use of nitrification inhibitors due to the identified GHG reduction potential and the comparatively low GHG abatement costs. Additionally, the use of green ammonia in fertilizer production should be further promoted. Although the results are exemplary for Germany, they can be very informative for other EU Member States with comparable socio-economic and agronomic conditions.

Conserving biodiversity, especially in agricultural landscapes, is a major societal challenge. Broad scientific evidence exists on the impacts of single drivers on biodiversity, such as the intensification of agriculture. However, halting biodiversity decline requires a systemic understanding of the interactions between multiple drivers, which has hardly been achieved so far. Selecting Germany as a case study, the goal of our analysis is (i) to understand how various socio‐economic drivers of biodiversity in agricultural landscapes interact at the national scale, (ii) to identify plausible pathways that most likely will lead to an improvement of biodiversity in agricultural landscapes and (iii) to discuss guiding principles for policy‐making based on the pathways. We applied the expert‐based Cross‐Impact‐Balance (CIB) methodology to the German agri‐food system (target year 2030). Seven descriptors that represent the most relevant socio‐economic drivers of biodiversity (here, we focus on species richness) in agricultural landscapes in Germany were defined. In three workshops with different groups of experts, we assessed all the interactions and impacts between these descriptors. From the workshops, seven overlapping scenarios were identified and aggregated into four main future pathways for enhancing biodiversity in agricultural landscapes. These pathways are: (1) ‘Innovation and stricter legislation’, (2) ‘Major change in protein production and CAP shift’, (3) ‘Major change in protein production and national legislation’ and (4) ‘Major social changes compensate for a lack of innovation in food production’. Socio‐economic drivers interact to varying degrees. Societal values have a strong active influence on the system, e. g. agricultural policy, whereas the orientation and objectives of agriculture, e. g. focus on public goods, are rather passively determined. Conserving biodiversity thus depends upon the evolution of societal values, European and national nature conservation and agricultural policies, innovations in plant and protein production as well as on global commodity markets. A key message for policymakers is that there are generally different, complementary options for achieving the objective of improving biodiversity. This is important when specific drivers such as the CAP cannot be steered in a particular desired direction. Read the free Plain Language Summary for this article on the Journal blog.

This contribution evaluates and examines the scope of 26 global carbon farming projects with a view to analyzing existing concepts for developing a business model for promoting carbon farming in order to generate valid carbon removal. It thus addresses an important aspect of the objectives of the European Green Deal. This study is based on a literature search analyzing four certification standards, an expert-based online survey, and an expert-based online workshop to evaluate different practice approaches identified by previous studies and additional information sources. The results highlight the theoretical potential of a result-based business model using agroforestry to fulfil the essential requirements to promote carbon farming for generating carbon removal. Although the study has limitations regarding the number of projects examined and experts consulted, there is a high probability that the underlying requirements could not be sufficiently fulfilled when translating them into practice. The identified concepts failed as a consequence of inadequate permanence assurance mechanisms, impractical measurement accuracy, poor precision in baseline scenarios, and lack of additionality. To remedy this, we recommend a shift away from a pure focus on promoting carbon farming to achieve carbon removal towards promoting the co-benefits of carbon farming. Further research should evaluate the extent to which stakeholders are interested in giving their financial backing to these co-benefits.