Introduction The National Monitoring Network on Nutrient Management (LMM) is a long-running Dutch monitoring programme that evaluates the effects of agricultural practices on water quality, directly linked to national and EU nutrient policies (including the Nitrates Directive). It monitors a fixed panel of more than 450 agricultural holdings across different soil types and farming systems and operates a data pipeline that combines detailed farm-level information (e.g. nutrient applications, crop and livestock data) with water quality measurements (e.g. nitrate and phosphate concentrations). Methodologies Water quality monitoring Farm accounting (FADN/FSDN) Farm level data collection Sampling and stratification Output Monitoring and reporting system with very detailed (farm level or parcel/crop level) data on farming practises and water quality data. Impact Ability to monitor the impact of manure policies and farming practises on water quality. This data set is used to evaluate and develop more targeted policies to achieve the environmental objectives at the lowest possible costs. What I can offer Capture LMM’s sampling design, QA/QC rules and data structures as a “best practice” for nutrient and water quality monitoring Expertise on farm level monitoring Expertise on data integration of private sector and public dataset Expertise on indicator definition Monitoring expertise What I need Jointly explore how LMM can act as a node/user in future data spaces and how new EO/sensor data could be integrated technically and organisationally Sharing best practises with other use cases Link to other ontologies and initiatives

Source: Annual AgData Use Case Summit 2026 booklet.