Agroclimatic zones of Norway – classification of agricultural land based on three phenological crop models

Authors: Dorothée Kolberg , Eva S. F. Heggem, Anne K. B. Olsen, Mats Höglind, Hugh Riley and Sigridur Dalmannsdottir.

In Norway agroclimatic zones (ACZs) are a valuable tool for national analyses in subject areas concerning optimized management of agricultural land resources. However, current Norwegian ACZs have been criticized for an outdated standard climate normal (1931-1960), limited representation of local climatic variation, lack of important model pa-rameters, and weak methodological documentation. Therefore, this paper presents new ACZs for Norway that address these weaknesses. The most significant methodological updates are use of standard climate normal 1991-2020, additional weather data variables, downscaling of weather data to 250 m hexagons, and the incorporation of phenological crop models for spring wheat, spring barley, and forage grass. The grass model was cali-brated with number of grass harvests at research stations, while the grain models were calibrated with subsidy claim data. Modeled zones for the three crops were combined into general ACZs. Example maps of crop zones and new ACZs for selected regions and the whole country are presented. The new ACZs are more robust, agronomically relevant, and better aligned with current climatic conditions in Norway. Deliberate exclusion of other factors than climate ensures the new ACZs’ national comparability and their applicability in policy development, land‑use planning, climate adaptation, and agronomic assess-ments at the national scale

Includes; Model Code and Supplementary Methods as text files. Replication Data: the file contains one row per grid cell from the ACZ export table. The dataset was derived from the PostgreSQL/PostGIS table prior to map dissolving and clipping to water bodies.