Within the field day "Alfalfa Cultivation and Climate Adaptation," Holger Gerdes and Zoritza Kiresiewa (Ecologic Institute) presented a draft policy paper on sustainable subsoil management in Germany. The objective was to collaboratively develop core recommendations – together with farmers, soil experts, and policy stakeholders – on how to more effectively promote deep-rooting crops, particularly alfalfa. Discussions centered on strategies for securing yields during drought years and on adapting political frameworks to make alfalfa cultivation more attractive.

Recommendation 1: Creating Incentives for Alfalfa Cultivation

Participants emphasized that alfalfa, as a perennial crop, not only offers economic advantages (e.g., lower input and operational costs compared to annual crops) but also contributes to humus accumulation, biodiversity conservation, and erosion control. To strengthen market uptake of alfalfa products, the following approaches were proposed:

• Feed Production: Processing alfalfa into green meal or pellets—especially for poultry feed, where demand is high.
• Organic Fertilizer Generation: Pelletizing alfalfa stems and leaves for use as organic fertilizer. New pelleting facilities would be required to meet growing demand in organic farming, particularly given tightening fertilizer regulations.
• Further Processing and Innovation: An on-farm biorefinery at the University of Hohenheim (ProGrün project) was highlighted as an example, where protein-rich grass clippings are converted into bioplastic. Additionally, separating leaves and stems could enable alternative valorization pathways (e.g., stems for paper production). To minimize nutrient losses, establishing circular nutrient loops was deemed essential.

Existing agri-environment schemes already provide entry points: for example, Hesse's five-year program for perennial forage cultivation. However, to secure broader political and public support, it is crucial to clearly communicate alfalfa's ecological potential (humus accumulation, insect habitat provision, erosion protection) alongside its economic competitiveness (e.g., versus maize). Tailored informational materials can persuade decision-makers to integrate alfalfa incentives into Eco-Schemes (Pillar 1) or Agri-Environment Programs (Pillar 2) of the Common Agricultural Policy.

Recommendation 2: Enhancing Knowledge Transfer to Translate Innovations into Practice

Another focal point was how to more effectively convey practice-oriented knowledge about subsoil management and alfalfa cultivation. Key target groups include:

• Schools and Vocational Training Institutions: Abstract terms such as "subsoil management" should be reframed into concrete topics like soil fertility, closed nutrient cycles, and alfalfa's role as the "queen of forage crops." It was noted, however, that in an era of increasing plant-based dietary awareness, "animal feed" may carry mixed connotations. In this context, framing alfalfa within global food security and regional value chains can foster broader understanding.
• Agricultural Advisors: Advisors should receive specialized training to integrate subsoil topics into their extension services. Educational materials must include regionally differentiated guidelines that address local site conditions.

Moreover, the integration of practitioners into living labs was underscored. The "Leitbetriebe Ökologischer Landbau in NRW" project serves as a good-oractice example, where farmers are financially compensated for their roles as co-researchers. Crucial elements include adequate compensation for opportunity costs (e.g., foregone cash crop income) and long-term funding horizons of at least ten years. The ongoing revision of the federal ordinance on vocational training for farmers represents an opportunity to embed subsoil management modules in the curriculum.

Outlook and Practical Implications

The workshop's recommendations will be incorporated into the final policy paper, providing policymakers with concrete guidelines for promoting deep-rooting crops. By combining market-oriented incentives with targeted knowledge transfer, the aim is to establish alfalfa as a climate-resilient crop in practice. This approach will enhance subsoil functions, mitigate drought risks, and support the long-term development of sustainable crop rotations.