Winter Cropland Cover in Germany: A Climate-Smart Agriculture Approach

Strategic Insights -

Research conducted by the Thunen Institute of Farm Economics, in collaboration with other institutions, has investigated the importance of winter cover on croplands in Germany. The study aimed to assess the spatial and temporal patterns of winter cropland cover across Germany from 2017 to 2023. The findings reveal a significant increase in green cover, from 17% in 2017/18 to 21% in 2022/23, and a decrease in bare soil from 20% to 12%. This shift towards more protective winter management is crucial for climate-smart agriculture and greenhouse gas mitigation.

Key Takeaways:

  • Continuous winter cover on croplands reduces soil erosion and enhances soil organic carbon.
  • Spatially and temporally explicit data on winter cropland cover remain limited across Europe.
  • The study used spectral unmixing-derived fractional cover time series from Sentinel-2 and Landsat imagery to assess winter cover types.
  • Four winter cover types were distinguished: winter crops, green cover (including cover crops and spontaneous vegetation), residue cover, and no cover (bare soil).
  • Phenological metrics were derived for green cover to assess vegetation duration, biomass accumulation, and termination type.
  • The results show a shift towards more protective winter management, with green cover increasing and bare soil decreasing.
  • Green cover was most frequent in northwestern and southern Germany, while bare soil remained prevalent in central and eastern regions.
  • Classification results showed good agreement with Integrated Administration and Control System (IACS) parcel-level records of winter cover crops and agricultural census data at the federal state level.
  • Remote sensing estimates consistently exceeded reported cover crop shares, reflecting the presence of non-subsidized or spontaneous vegetation.
  • The study provides valuable input for enhanced erosion and carbon modeling and establishes a basis for monitoring and future evaluation of Common Agricultural Policy (CAP) instruments.

Statistics:

  • The share of green cover increased from 17% in 2017/18 to 21% in 2022/23.
  • The share of bare soil decreased from 20% to 12% from 2017 to 2023.
  • The F1-Score of classification results was 0.68 for winter cover crops and 0.82 for agricultural census data.
  • The Mean Absolute Error (MAE) was 5 percentage points for agricultural census data.

Sources:

  • Characterizing spatio-temporal patterns of winter cropland cover in Germany based on Landsat and Sentinel-2 time series. International Journal of Applied Earth Observations and Geoinformation, 2025, 142():104728.