Ammonia emissions from German animal husbandry

Ammonia emissions from German agriculture were estimated for the years 1990, 1995, 1999 and 2010 based on current practices and trends, and forecasted for 2010 based on potentially achievable reductions and the cost involved. Emission factors for animal housing, manure storage and application were determined based on the authors own and published investigations, and agreed to at the national level. The different animal husbandry systems and manure treatment techniques common in Germany were considered in the study. Data and information on the application extent of these systems and techniques were generated by conducting surveys in different regions typical of Germany. Using this information and the data on livestock numbers, available from official livestock censuses, ammonia emissions from German agriculture were calculated. According to the calculations performed, ammonia emissions from animal husbandry amounted to 610 10(6) kg (Gg or thousand tons) in 1990 and fell to about 470 10(6) kg in 1999. This sharp decrease is ascribed to the strong decline in livestock numbers in the new Federal States between 1990 and 1992 after the German reunification. Potentials of abatement techniques were calculated against the background of international agreements on emission reduction. Emission reduction should begin with a nutrient-adapted feeding. Plowing under manure directly after application constitutes an effective and economical measure for all livestock categories. Other areas particularly suited to reducing ammonia emissions depended on livestock category. According to the different abatement scenarios performed, Germany can meet its commitment to reduce the total ammonia emissions to 550 10(6) kg by 2010 assuming further technological development.