July 2025 Release

This post outlines the recent updates to the FDM libraries: @svenvw/fdm-core, @svenvw/fdm-calculator, and @svenvw/fdm-data. This release introduces a robust derogation management system, implements the 2025 Dutch fertilizer norms, and enhances data management capabilities to provide a more comprehensive and compliant precision farming experience.

Comprehensive Derogation Management

A significant addition to @svenvw/fdm-core is the introduction of a full suite of functions to manage derogations for farms. This is essential for farmers who need to operate under specific exemptions from standard regulations.

• Derogation Functions (@svenvw/fdm-core):
  • addDerogation: Allows for the addition of a derogation for a specific farm and year.
  • removeDerogation: Enables the removal of a previously granted derogation.
  • listDerogations: Retrieves a list of derogations per year for a farm.
  • isDerogationGrantedForYear: Checks if a derogation is active for a given year.

Advanced Farm and Data Management

We've introduced several new features and improvements to give users more granular control over their farm data.

• Field Removal (@svenvw/fdm-core):

  • The new removeField function allows for the complete deletion of a field, including all associated data such as cultivations, soil analyses, and fertilizer applications.

• Harvest Updates (@svenvw/fdm-core):

  • The updateHarvest function has been added, allowing users to modify the details of a harvest event after it has been created.

• Refined Acquiring Methods (@svenvw/fdm-core):

  • The b_acquiring_method options have been refactored to align with the official RVO codes, ensuring better standardization and interoperability.
  • The listAvailableAcquiringMethods function has been introduced to retrieve all possible acquiring method options.

• Cultivation Plan Enhancements (@svenvw/fdm-core):

  • The getCultivationPlan function now includes the b_area (area in hectares) in its output, providing a more complete overview of the cultivation plan.

Detailed Implementation of 2025 Dutch Fertilizer Norms

@svenvw/fdm-calculator has been significantly updated with the latest Dutch fertilizer regulations for 2025, a critical update for our users in the Netherlands. The new implementation automates the complex calculations for three key usage norms (gebruiksnormen), ensuring that farm management plans are compliant with national environmental regulations. For a complete breakdown, you can refer to our detailed documentation on the 2025 Dutch Fertilization Norms.

Here’s a summary of what the calculator now handles:

• 1. Nitrogen Usage Norm (Stikstofgebruiksnorm):

  • The calculator determines the maximum allowable nitrogen application by identifying the main crop and the field's geographical context (soil region and whether it's in a Nutrient-Polluted Area, NV-gebied).
  • It applies specific rules for crops like temporary grassland, potatoes (variety-specific), and maize (derogation-dependent).
  • Crucially, it also calculates the potential reduction (korting) based on the use of catch crops or winter crops in the previous year on sand and loess soils.

• 2. Phosphate Usage Norm (Fosfaatgebruiksnorm):

  • This norm is calculated based on the land use type (grassland or arable land) and the soil's phosphate status, which is determined from the latest soil analysis data (P-CaCl2 and P-Al values).
  • The soil is classified into one of five categories (Arm to Hoog), each with a corresponding phosphate application limit.

• 3. Animal Manure Usage Norm (Dierlijke Mest Gebruiksnorm):

  • This norm is determined by the farm's derogation status for 2025.
  • For farms with a derogation permit, the norm is adjusted based on whether the field is located in a sensitive area, such as a Nutrient-Polluted Area (NV-gebied) or a Groundwater Protection Area (GWBG-gebied).

Data Corrections and Improvements

• brp Catalogue Update (@svenvw/fdm-data):
  • The values for b_lu_yield in the brp cultivation catalogue have been corrected to ensure more accurate yield estimations.

Bug Fixes and Maintenance

• Harvest Removal Bug (@svenvw/fdm-core): A bug that caused an exception when removing a cultivation with an associated harvest has been fixed.
• Crop Residue Calculation (@svenvw/fdm-calculator): A fix has been implemented for the calculation of crop residue biomass in the nitrogen balance.
• Dependency Updates: All packages have been updated with the latest dependencies.

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These updates reflect our ongoing commitment to providing a robust and comprehensive platform for farm data management. We encourage you to explore these new features and welcome any feedback or contributions on our GitHub repository.