Introduction The purpose of this use case is to develop measures to facilitate upload of and access to data from agricultural Long-Term Experiments (LTE) throughout Europe and to increase visibility, quality and reusability and of valuable agricultural LTE (meta)data. Simulation models help to understand long- term impacts of climate and management practices on crop production (and vice versa). These models require FAIR agricultural data in standardized and harmonized formats and if possible, as complete and long-time series. Methodologies LTE data are potentially valuable data sources which are yet rarely available. The Leibniz Centre for Agricultural Landscape Research (ZALF), Germany, developed a data infrastructure to collect and process LTE metadata and experimental data and provides services to scale and aggregate data to the required resolution. A LTE data scheme provides data owner to enter and submit experimental data and metadata in standardized form: https://doi.org/10.20387/bonares-jrhx-r965. Currently, experimental data from eleven and metadata from some 570 LTE trials in Europe are published in the LTE Map (https://lte.bonares.de; Dönmez et al. 2026, https://doi.org/10.1016/j.compag.2026.111534). More effort is needed to capitalize experimental data with our high-quality standards in Germany and Europe. Within the German project FAIRagro (2023-2028) new LTE (meta)data submissions are curated by data stewards and a plausibility database to assess data quality and learn from incomplete LTE data is developed by experts. Output and Impact This use cases provides measures and a workflow to • expand the visibility and outcomes of these efforts from national to European scale. • publish a “LTE data publication and curation guideline” • provide information about data quality, completeness and plausibility levels for published LTE data What I can offer / What I need Experiences in LTE (meta)data management + quality assessment on European scale

Source: Annual AgData Use Case Summit 2026 booklet.