P budget calculations of German farmland and resulting manure surpluses in livestock hotspot regions

The agricultural sector in Germany is characterized by regionally spezialised managing systems. Livestock and biogas production is concentrated in the northwest and the south east regions, resulting in locally high amounts of manures (organic fertilizers such as slurry and digestates).

The research work described here aimes at the budgeting of soil P on district level, and further the assessment of regional surplus of P in agricultural systems, in order to evaluate strategies for regional manure export and/or appropiate manure processing systems. Based on soil P budgets and two P-depletion scenarios, a manure surplus and thus a transporting or manure processing potential of about 20 – 30 million t FM per year is calculated, which is about 9 – 14 % of the total manure in Germany.