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December 2025 Release

· 4 min read
Sven Verweij
Sven Verweij
Project Manager @ NMI

As we approach the end of the year, the December release of the Farm Data Model (FDM) focuses on looking ahead to 2026 while refining the tools you use today. We have upgraded our Nitrogen Balance insights with deeper breakdowns and integrated high-resolution AHN4 elevation data into the Atlas. Additionally, we've introduced initial support for the 2026 Dutch fertilizer application norms, acting as a placeholder while final political decisions are still pending. Under the hood, we've improved type safety across our packages and streamlined the authentication experience.

Preparing for 2026​

  • 2026 Support: You can now create farms and plan cultivations for the 2026 season.
  • Updated Norms & Regulations: The calculator has been updated to support the Dutch fertilizer application norms for 2026.
    • Current Implementation: Please note that for the time being, the 2026 calculations are based on the 2025 norms, with the important exception that derogation is no longer available, reflecting the ongoing phase-out.
    • Looking Ahead: We will be monitoring the political discussions regarding the gebruiksruimte for 2026. As soon as new regulations are officially publicized, we will update the calculator to ensure compliance.

FDM Application Enhancements (@svenvw/fdm-app)​

  • Atlas Upgrades:
    • AHN4 Elevation: We have integrated the AHN4 dataset into the Atlas, providing high-resolution elevation data for detailed field analysis.
    • Map Engine: We have transitioned from Mapbox to MapLibre, ensuring a robust open-source foundation for our mapping capabilities.
  • Deep Dive into Nitrogen Balance:
    • Interactive Charts: The nitrogen balance charts for both farm and field have been significantly upgraded. We've introduced a distinct color palette to visually separate sources like supply, removal and deposition at a glance.
    • Detailed Insights: Hovering over any segment of the chart now reveals precise figures and details.
    • Field-Level Precision: On the field balance chart, we go even further—you can now see the exact contribution of each individual fertilizer application, giving you insight into how every action affects your field's nitrogen balance.
  • Nutrient Advice & Farm Management:
    • Cultivation Selection: We've improved the Nutrient Advice and Fertilizer Application Metrics views, allowing you to easily select specific cultivations for targeted advice.
    • Farm Overview: A new farm overview page within the Nutrient Advice module makes navigating between fields and cultivations smoother.
  • User Experience:
    • Authentication: The login flow is now smoother with a redesigned OTP verification page and improved accessibility. When using magic links, you now have the flexibility to either manually enter the OTP code or simply click the button in your email to have it automatically filled in and verified. We've also refined the redirection logic—only first-time social logins are guided to the onboarding page, while returning users are taken directly to their work.
    • Landing Page: The landing page has been refreshed with more detailed information about FDM's capabilities and improved mobile responsiveness.

FDM Calculator Refinements (@svenvw/fdm-calculator)​

  • Precision & Consistency:
    • Unified Data: We have unified the data shape for nitrogen balance results across farm and field levels, ensuring consistent reporting.
    • Nature Terrain: Adjusted logic for nl_335 (Nature terrains/heathland) to correctly classify it as non-arable land (geen bouwland).
    • Target Values: Corrected the nitrogen balance target value for arable crops on dry clay soil to 115 kg N/ha (previously 125 kg N/ha).
    • Catch Crops: Fixed the calculation for the fertilizer application discount (korting) when a catch crop is sown on October 15th.

Technical Improvements (@svenvw/fdm-core, @svenvw/fdm-data)​

  • Type Safety: We have achieved full type safety across fdm-data, fdm-calculator, and fdm-core, including inferred dependencies within our monorepo structure. This significantly improves developer experience and code reliability.
  • Performance:
    • Docker: Optimized the Docker build process for faster and more efficient deployments.
    • Security: Implemented read-safe OTP generation for magic links and added custom rate limiting for the verification endpoint.
    • Analytics: Setup a reverse proxy for PostHog to improve analytics reliability.

This release gets FDM ready for 2026 with the new regulations and better tools. We hope these updates help you in your work and wish you a good start to the new year.