Vergleichende Untersuchungen zur N-Bilanz unter Dactylis glomerata L. nach Gülle-, Biogas-Gülle- und Mineral-Düngung. 3. Mitteilung. N-Bilanz

Supplementary to the first communication (Dry matter yields and nitrogen withdrawal) and the second communication (Nitrate leaching and nutrient contents in the soil) this third communication reports on N-losses via denitrification and volatile ammonia losses. In addition to this, the calculation of a nitrogen (N) balance is attempted. The measurements on denitrification as carried out in a diploma thesis did not result in N-losses of relevance for the N-balance. The determination of ammonia losses had to be discontinued since impossibility to change the sites of measurement - threatened to interfere with the trial. In total, ammonia losses can only be considered to be partially responsible for the low N-recoveries after fertilization with slurry. A nitrogen balance as based on the parameters fertilization, withdrawal, leaching and accumulation in the stubbles resulted after correction for the control in a calculated recovery of the fertilizer nitrogen of 72,6% with mineral fertilizati on, 23,8 % with untreated slurry and 25,6 % with mature slurry.