Researchers investigating the social acceptance of new technologies often take a socio-systemic approach (Wüstenhagen, et al., 2007; Ellis et al., 2023; Torma and Aschemann-Witzel, 2024) based on processes that operate at three levels. In the present study, we interpreted these three levels as follows: (1) micro level: the smallest unit of analysis that represents the individual perspective, (2) meso level: includes various informal social group affiliations as well as formal associations and networks, and (3) macro level: the highest level of analysis, encompassing political structures and governance processes.

To identify representative interview partners for the implementation of agricultural CDR-related practices in Northern Germany, we utilized the above concept to divide our 120 contacts into these three levels (Figure 1). All farmers with or without CDR experience (soil carbon sequestration, biochar, and agroforestry) were assigned to the micro level. Farmers’ associations, agricultural advisors, biochar producers, environmental associations, non-governmental organizations, and regional networks were assigned to the meso level. The macro level included representatives of local or regional authorities involved in agricultural issues. For the micro level, we sent invitations by email to all the farmer contacts we selected. For the meso level, we prioritized those who we assumed might have an interest in CDR. For the macro level, we contacted all representatives who worked wholly or partly in the agricultural sector and might have had CDR on their agenda.

In total, we sent 63 initiations via email for the interviews. The response rate with interview confirmation was 46%. We continued sending invitations until few or no new insights appeared to be generated and concluded that theoretical saturation had been reached at 29 interviews.

All the interviewees signed an informed consent form before appearing for the interviews. The consent form contained information regarding the study aim, project, content, and data protection rights and assured anonymity. The interviewees did not receive any compensation.

We conducted 29 interviews with 34 participants between January and July 2023. The interviews typically lasted about an hour, but when more than two people participated, the interview duration was extended to 1.5 h. All interviews were conducted online, with the exception of four on-site interviews. The interview language was German.

If the interviewees agreed, the interviews were recorded and later transcribed. Three interviews were not recorded owing lack of permission, but we ensured that the researchers who conducted the interview took notes.

The interview guide was adapted according to the interviewees’ work profile and relation to CDR, knowledge and experience in general and specific CDR practices, evaluation of CDR methods, and informational and knowledge needs. Following feedback from three test interviews, the questions were revised to improve the clarity of the phrasing. The interview guide is presented in Appendix A.

Each interview was assigned an identifier for the analysis. The numbering corresponds to the order in which the interview was conducted. Each identification number was assigned a corresponding level. For example, an interview with a farmer from the meso level was coded #1_meso.

We conducted a qualitative content analysis of the transcribed interview data (Schreier, 2012; Mayring, 2014). The core of the analysis was to assign successive parts of the qualitative data to categories of a coding scheme. We built a coding frame for each of the three levels (micro, meso, and macro). The coding was then extended to single CDR practices: soil carbon sequestration, biochar application, and agroforestry. The coding scheme also captured when and how participants first heard about CDR and how they would like to receive missing information (see Appendix B).

To ensure that we captured knowledge needs holistically, we used the six descriptive dimensions of the CDRterra assessment framework (Havermann et al., 2024) as an analytical framework. Each dimension was described using a guiding question (Figure 2). We used these guiding questions (Havermann et al., 2024) as inspiration sources to identify knowledge needs in our qualitative data. To facilitate the use of our findings in future transcapillary dialogues (Kirchhoff et al., 2013) and co-development processes (Hewitt et al., 2020), we documented the interviewees’ knowledge needs as information needs.

For quality reasons, we coded the qualitative content analysis in a two-phase step. One author (GL) started the coding process, and a second author (JEZ) critically assessed the coding and revised it. The analysis of the interview data was flexible and dynamic, owing to its qualitative nature (Schreier, 2012; Torma and Aschemann-Witzel, 2024). MaxQDA and Microsoft Excel were used for the analysis.

At the beginning of each interview, we introduced our project and the scientific definition of CDR to the interviewees. During the interviews, it became clear that some interviewees had an incomplete understanding of CDR. This misconception regarding CDR emerged mainly among interviewees at the meso and micro levels. For example, some interviewees assumed that they were already active in CO₂ removal but listed methods that only lead to the reduction of CO₂ or other greenhouse gas emissions:

We asked all interviewees whether they had heard of CDR before the interview and whether they could remember when they first came across the topic. All participants were familiar with CDR-related practices; however, only 18 of the 29 respondents were familiar with the actual concept of CDR. The earliest year an interviewee reported having heard of the concept of CDR was 2013. We observed that most interviewees found out about CDR in 2018 and 2019. We also observed that practices for carbon sequestration in the soil and humus build-up have long been known in the agricultural sector. The actors were not concerned about the climatic aspect but only soil health; the effects on the climate system were rather new for some actors.

Although the interview guide was open to all possible land-based CDR methods, the discussion mainly focused on three CDR practices: soil carbon sequestration, agroforestry, and biochar application.

The interviewees highlighted the need for knowledge across all six dimensions: Climate change mitigation, Technological conditions, Environmental impacts, Economics, Policy & government, and Social aspects (Figure 2). A total of 22 information needs were identified, with each dimension encompassing 4 questions, except for the dimensions Policy & government and Social aspects, which had only 3 questions each. Most of the statements in the interviews led to information needs related to Economics, followed by Climate change mitigation and Policy & government (Figure 3). Questions regarding other dimensions were equally important for the interviewees.

We analyzed the relative frequency of the statements provided by the interviewees at the micro, meso, and macro levels that led to the 22 information needs (Figure 2). The analysis revealed that most of the questions were asked by farmers compared with interviewees from the meso and macro levels. Local and regional authorities articulated the least need for information. They were less concerned about single CDR practices but had more questions regarding CDR practices in general.

Farmers had questions regarding both specific and general CDR practices. Their interest was highest in the Economics dimension. Interestingly, farmers also showed a high interest in Social aspects, followed by Technological conditions. Actors at the meso level contributed equally to the information needs, showing the highest interest in the Economics dimension, followed by Climate change mitigation and Policy & government.

We asked the participants about the sources from where they usually obtained their information about climate change and climate mitigation. The media, including news, social media, and podcasts, was one such source. Some farmers mentioned agricultural journals as a source of information. Some actors at the meso and macro level had subscriptions to scientific-based newsletters. However, many actors expressed that they searched the Internet whenever they wanted to know something new.

We also asked the participants their preferred methods for compiling the research findings and missing information regarding CDR. Interestingly, farmers and some meso and macro level actors also stated that dealing with the latest scientific findings was beyond the scope of their daily responsibilities. However, all interviewees agreed that, regardless of the format, the information contained should have strong practical relevance, be presented in simple language, and be well visualized. In terms of formats, the interviewees mentioned that the traditional transfer of information from science to practice is often not feasible. All interviewees reported non-applicability of reports or brochures. Interviewees explained that they did not have sufficient time and often did not understand the scientific procedure.

Actors at all levels expressed a clear need for scientific results in the form of recommendations for actions, guiding materials, or concepts (Figure 4). Farmers often mentioned that they wanted to know exactly how effective the CDR method was and what its advantages and disadvantages were (see section 3.2).

The authorities enact laws that are closely linked to the support measures and thus influence the practices of farmers. Therefore, one farmer expressed their wish to receive guidelines directly from the authorities:

Farmers also mentioned that for the procedure of developing guidelines to enhance the implementation of agriculture-based CDR, improving the communication between farmers and authorities would be recommended.

Actors at the meso-level also expressed a strong need for guidance.

One interviewee suggested creating guidance materials for biochar; researchers should first bring all market players together to jointly develop the most useful and practical information. Another interviewee of the meso-level noted that there was often a lack of ability to convert data and information into sustainable actions.

At the regulatory level of authorities, guidelines were asked for with suggestions for measurement and control mechanisms:

Online formats are another favored format for the transfer of research results. Some appreciated that in such a format, the key points could be presented with the possibility of reaching out to those who are more interested in the topic. Short explanatory videos used in social media were also often mentioned by farmers.

Actors at the meso-level expressed that they also perceive a danger with some online formats:

Instead, actors of the meso level seem to instead favor online platforms or databases. Such platforms provide an overview of the pros and cons of CDR methods with links for further information.

Actors of the authority level were thinking about how to better connect the data collection processes between farmers and the administration level.

Training formats on farms, where either farmers teach other farmers or researchers demonstrate findings directly on the ground, were also mentioned as suitable formats for knowledge transfer but with less intensity than guidelines and online formats.

While the qualitative and regional nature of this study limits the generalizability of the findings, the patterns identified here may resonate with agricultural sector experiences in comparable settings. It is also important to stress that the respondents in this study were not equally divided among the three levels, with most actors belonging to the meso level. Recruiting additional participants from the authorities was difficult. At the time of conducting the interviews, CDR was not a high political agenda in Germany yet. No explicit policy regarding CDR in general or specific CDR targets for the agricultural sector had been established in Germany or in the European Union.

Further, we cannot exclude the possibility of a social desirability bias in our study. Actors in the agricultural sector of Northern Germany are well-connected. Interviewees could have perceived some risk in sharing their honest views or that they might have withheld information, influencing the results. This may have especially been the case for the interviewees working in higher administrative institutions.

In this study, we explored what agricultural actors in Northern Germany need to know and how they would like to receive missing information using a one-way communication channel. The next step is to go beyond consultation and initiate an intensive, iterative exchange with the selected agricultural actors (Steuri et al., 2022). The catalogue of information needs can serve as a starting point for follow-up transdisciplinary dialogue. Our findings are of equal importance for future research in the form of co-developed actionable knowledge between researchers and agricultural actors.

An interdisciplinary research team could go through each dimension and discuss for each of the 22 information needs whether there were already answers in the research or whether practitioners, such as farmers or politicians, would need to be consulted to answer the questions. Some questions highlight the need for further research.

However, in terms of knowledge distribution and adopting new practices, we found that farmers express relatively more trust in other farmers and associations and less trust in research institutions and agricultural authorities (Rust et al., 2022; Paulus et al., 2024). To turn the 22 information needs into action-orientated support of agricultural actors to enhance the implementation of agriculture-based CDR, it is recommended as a first step to understand the relationships between the agricultural actors in the region. A region-specific Agricultural Knowledge and Innovation System can be of great help. The concept is widely used to study processes of innovation co-development, knowledge and information sharing, and mutual learning around agricultural innovations (Knierim et al., 2015). For the study region, we learned from the regional AKIS (Bae et al., 2024) that the European Innovation Partnership of Agricultural Productivity and Sustainability EIP-AGRI initiative could be a promising entry point. The initiative has funded more than 50 innovation projects that have successfully strengthened the connection between farmers, advisors and researchers (Bae et al., 2024); however none of the funded projects so far focused on agriculture-based CDR (personal information from interviewee).

It is also highly relevant to include agricultural partitioners to take full advantage of the strengths of farmers’ informal knowledge, which can be used to test scientific knowledge (Šūmane et al., 2018). In our study, some farmers expressed interest in trying new practices on their own initiative and spoke in favor of seeking greater appreciation from the scientific community for their own experiments. An increasing number of research has discussed the complementarity of informal farming and formal scientific knowledge and points to the necessity of combining them to achieve the best results (Šūmane et al., 2018; Klein et al., 2024; Moreno-Pérez et al., 2024).

We emphasize that increasing the use of CDR-related practices in the agricultural sector depends on providing actionable knowledge to farmers and their associations as a priority, and secondarily to other agricultural actors. Consequently, the co-development of such knowledge needs to build on science and a strong transdisciplinary approach, integrating actors at the eye level, from the agricultural sector and beyond.