This Excel data set contains example calculation of a simplified reference factor for estimating the amount of maize silage used as cattle feed in the Weser-Ems Region. It serves as a supplementary data to the publication "Remote sensing-based long-term assessment of bioenergy policy impact on agricultural land cover change: A case study of biogas in the Weser-Ems region in Germany" (Beila et.al, 2025).

The reference factor calculated here describes the area of maize silage necessary to satisfy the need for the feeding of livestock (in livestock units – LU). Calculations are applied on the level of municipalities. Since agricultural activities are taking place mostly in the rural area, the urban administrative units – five city municipalities of the Weser-Ems region (Delmenhorst, Emden, Oldenburg, Osnabrück, and Wilhelmshaven) were excluded from the analysis. As the year of reference, the year 1999 is used, as it represents the situation in the Weser-Ems region prior to the start of biogas production. 

"Calculated" indicates values that are calculated using the following equations:

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RF1999 = TMA1999/C1999 (Equation 1)

where
RF1999 - the reference factor
TMA1999 - the total silage maize area (in ha) in the municipality in 1999
C1999 - the number of cattle (in LU) in the municipality in 1999

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CMA2004-2019 = C2004-2019 x RF1999 (Equation 2)

where
CMA2004-2019 - the silage maize area (in ha) in the municipality needed for feeding cattle in the years 2004, 2009, 2014 and 2019 respectively
C2004-2019 - the number of cattle (in LU) in the municipality in the years 2004, 2009, 2014 and 2019 respectively
RF1999 - the reference factor

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BMA2004-2019 = TMA2004-2019 - CMA2004-2019 (Equation 3)

where
BMA2004-2019 - the silage maize area (in ha) in the municipality used for biogas in the years 2004, 2009, 2014, and 2019 respectively
TMA2004-2019 - the total silage maize area (in ha) in the municipality in the years 2004, 2009, 2014 and 2019 respectively
CMA2004-2019 - the silage maize area (in ha) in the municipality needed for feeding cattle in the years 2004, 2009, 2014 and 2019 respectively

In addition, shares of silage maize are calculated as percentage (%) of the total agricultural area and of the total maize area.


"Modelled" indicates values of the total agricultural crop area and the total maize silage area in years 1999, 2004 and 2009 per municipality obtained using historical satellite images in a remote-sensing based land cover prediction model. The model was developed by the authors of the reported study. It is a random forest machine learning model trained and tested to map crop types in each field using remote sensing time series satellite data and the integrated administration and control system (IACS) data as ground truth data. More information about the model can be found in the main publication. Alternatively, statistical data (e.g. agricultural census data) can be used, if available.