Technical backdrop for the designation of nitrate-loaded areas in accordance with § 13a Fertilisation Ordinance 2020 (DüV 2020) in Brandenburg

§13a of the Fertilisation Ordinance contains, inter alia, an obligation on the Land governments to issue regulations for areas of groundwater bodies that require special measures and regulations due to nitrate pollution. These areas are presented in this technical setting and are updated in accordance with the legal requirements of DüV 2020 and AVV GEA. The basis for the technical backdrop is the provisions of the General Administrative Regulation on the designation of areas contaminated with nitrate and eutrophicated (AVV GEA) of 3 November 2020, in particular §§ 4-10. First, the groundwater measuring stations were identified where the threshold of the groundwater regulation (50 mg NO3/l) is exceeded. Based on this, geostatistical methods (§ 6 of the GEA AVV) delineate areas to which the threshold exceedances refer. For the areas thus determined, an emission-based determination of nitrogen balances is carried out on the basis of modelling results of the Thünen Institute, taking into account nitrogen supply and nitrogen removal (§ 8 of the AVV GEA). If the nitrogen balance thus determined exceeds the maximum tolerable nitrogen balance (based on modelling results of Forschungszentrum Jülich according to § 7 of the AVV GEA), the agricultural land used for the determination of high emission risk shall be classified. The result is the present landscape, which in turn forms the basis for the field block-related exclusion of the areas relevant to measures. All IACS field blocks, which are more than 50 % of their area in the specialist setting, are subject to special requirements for fertilisation.