Unterschiedliche technische Behandlung von Gülle und deren Auswirkungen auf intensiv genutztes Dauergrünland

Technical treatments of slurry and their effects on intensively managed permanent grassland
Since 1987, seven different technical methods for slurry treatments were compared at a permanent grassland sward in South Germany. The effects on botanical composition of the grassland sward, dry-matter yield and soil nutrient parameters were registered. The experiment includes the variants: mixing with a special slurry pump, separation (liquid and solid phase and composted solid phase), aerification and anaerobic fermentation in a biogas plant. Only slight effects of different treated slurry on the botanical composition could be shown. Comparing with mineral fertilization, the slurry variants had higher proportions of legumes and forage herbs. The dry-matter yield was not influenced by slurry treated differently. The utilization of slurry nitrogen could be increased on average to 90 % during the experimental period compared to mineral nitrogen. Separation of slurry and fertilization in the liquid phase increased the utilization of nitrogen.