Fur die N2O-Emissionen aus der Lagerung von Festmist wurde anhand einer Literaturstudie gepruft, ob nationale Emissionsfaktoren fur Deutschland definiert werden konnen. In Deutschland uberwiegen stroharme Festmiste aus der Rinder- und Schweinehaltung, die in der Regel bis zu 6 Monate in offenen Mieten ohne weitere Behandlung gelagert werden. Den Literaturergebnissen zufolge ist die O2-Verfugbarkeit in den Festmistmieten die wesentliche Steuerungsgrose fur die N2O-Emissionen. Eine belastbare Modellierung der N2O-Emissionen aus Festmist aufgrund von Substrateigenschaften und Management ist jedoch nicht moglich. Aus 10 als reprasentativ fur die deutschen Substrat- und Lagerungsverhaltnisse ausgewahlten Messungen wurde ein Emissionsfaktor fur die Festmistlagerung (Solid storage) von 0,013 kg N2O?N (kg N)?1 abgeleitet.

Nach der Veroffentlichung der Ammoniakminderungskosten fur Masnahmen bei der Lagerung und Ausbringung von Flussigmist [1, 2] werden in diesem Beitrag die Minderungskosten fur unterschiedliche Rohprotein-angepasste Futterungsvarianten in der Mastschweinehaltung vorgestellt. Die Berechnung der Minderungskosten erfolgte auf Basis selbst ermittelter Stickstoffausscheidungen und Emissionsfaktoren. Die starkste Reduzierung der N-Ausscheidung und damit verbunden der Ammoniakemissionen wird durch den Ubergang von der Universalzur Zweiphasenmast erreicht. Die Einfuhrung weiterer Phasenabschnitte fuhrt nur zu vergleichsweise geringen weiteren Minderungen. Die hoheren Kosten fur die Futterungstechnik und hoheren Aminosaureeinsatz bei der Mehrphasenfutterung werden durch Einsparungen teurer Eiweiskomponenten ausgeglichen. Abhangig von Referenzverfahren, Anlagengrose und durchschnittlicher Wachstumsleistung der Tiere entstehen negative Minderungskosten in Hohe von -2,92 bis -16,14 €/kg NH3. Bei den derzeitigen Kosten fur Anlagentechnik und Futtermittel kann daher von einer deutlichen Kosteneinsparung durch eine Rohproteinangepasste Mehrphasenfutterung ausgegangen werden.

The KTBL has updated calculations of the costs of measures to reduce ammonia emissions from agriculture. In the present paper the results for different covers for storages of liquid manure are presented. From the national emission inventory a surface-based reference emission factor without cover of 16 g • m-2 • d-1 for pig slurry without natural crust and 3.3 g • m-2 • d-1 for cattle slurry with natural crust is deduced. Notably the coverings by granules or straw are costeffective abatement measures (pig slurry: 0.26–0.36 resp. 0.48–0.63 €/kg NH3). Furthermore, the composition of the costs and cost-saving side effects are discussed.

Ammonia volatilisation from field applied slurries causes environmental hazards and loss of fertilizer value. Acidification of slurry, usually with inorganic or organic acids has previously been used to reduce NH3 emissions. In this study, we present an alternative technique for the acidification of slurry, namely the use of fermentation by endogenous microbes to form organic acids from readily degradable organic compounds. In laboratory experiments, the addition of different sugars (sucrose in dosages of 0.003, 0.01, 0.03, 0.1 and 0.3 mol l(-1), glucose in dosages of 0.05 and 0.1 mol l(-1)) and organic residues (sugar beet residues in dosages of 33 and 330 g fresh weight l(-1), biowaste at 50 g fresh weight l(-1)) to cattle slurry resulted in a considerable decrease in pH, with a minimum pH of 4.7. A subsequent pH increase indicated that the organic acids were probably further degraded with a resultant loss of acidity in the slurry. In a field study, the NH3 emissions from untreated and acidified (pH = 6) slurries were compared after field application (20 m3 ha(-1)). During the first 20 hours, the acidified slurry showed NH3 emissions of less than 5% of the applied ammonia compared to a 26% loss from the untreated slurry. The total emissions of NH4+-N were 32% for acidified and 54% for untreated slurry. Easily degradable organic amendments therefore have the potential to effectively reduce NH3 emissions from slurries and may be an alternative for the use of acids.

The storage and application of slurry induces nitrous oxide, methane and ammonia emissions. In various experiments we studied the influence of different slurry treatments, storage and application technologies on greenhouse gas emissions. The different treatments were compared in terms Of CO2-equivalents. Ammonia is an indirect greenhouse gas. Our results indicate that volatilization of NH3 has to be taken into account if mitigation strategies for greenhouse gas emissions are discussed. Methane and NH3 dominate the greenhouse gas emissions during storage. After application, N2O and NH3 are the main gases emitted. The most promising chain of measures to reduce the emissions of greenhouse gases seems to be anaerobic digestion of slurry followed by a covered and gas-tight storage allowing the use of the biogas being produced during storage. For application, immediate shallow incorporation after spreading with trail hose on arable land and trail shoe application on grassland are favorable techniques.

Ammonia volatilization from slurry in the field is either measured under open atmosphere from large field plots (integrated horizontal flux [IHF], mass balance) or in closed, ventilated chambers (e.g., wind tunnels), which allow the measuring of small plots but influence the climatic conditions. We conducted this study to evaluate a new method for measuring NH3 volatilization on small experimental plots under ambient climatic conditions (including rain and,wind). Various pretreated cattle slurries were applied to small plots (2 by 2 m) in tillering winter wheat (Triticum aestivum L.). Ammonia collected by passive samplers on manured plots was compared with NH3 collected on standard plots. where known rates of NH3 were being released via a tubing system (standard comparison [SC] method). Forty-five manured plots were measured simultaneously by comparison with two standard plots. The specific detection limit of this experiment was 2.5 mu g NH3-N m(-2) s(-1) (90 g NH3-N ha(-1) h(-1)). Below this value, the coefficient of variation of measured NH3 release exceeded 30%. Slurry was applied to plastic gutters on two control plots. Measured NH3 Losses front these plots accounted for 78% of the absolute NH4-N losses determined by sampling and analyzing slurry from the gutters. Measurement of the control plots was repeated during the ripening of the wheat. A strong deviation between the measurements of the two plots suggested that the accuracy of the new method is limited in dense vegetation. The results are discussed with respect to measurement accuracy and possible sources of error. A comparison with literature reports indicated that the accuracy of the SC method compared favorably to micrometeorological methods and wind-tunnel systems.

Strategies reducing NH 3 volatilisation from slurry include separation of slurry, special application techniques and additives. We studied the impact of manure separation and application technique on N 2 O release after manure application. Untreated and separated cattle slurry (dry matter content of 7.1% and 4.4%, respectively) was applied to winter wheat using broadcast and banded application and injection. The N 2 O emissions were measured at high frequency for 14 to 20 days after slurry treatment by the closed chamber method. Manured plots showed significantly higher N 2 O emissions than the control plots but neither dry matter reduction of slurry nor application technique significantly influenced the N 2 O emissions. The variability of N 2 O emission was influenced by the application technique and increased in the order: banded application – injection – broadcast application. There was no correlation between NH 3 losses from applied slurry and N 2 O emissions. Thus reducing ammonia volatilisation will not necessarily increase N 2 O emissions.

Ammonia volatilization from slurry is undesirable because of environmental N eutrophication and loss of fertilizer value. The dry matter content of slurry, the application technique and the weather conditions are the main factors influencing NH 3 losses from landspread slurry. In a field of winter wheat a two factor plot experiment was conducted to study single and combined effects of slurry separation and application techniques, including broadcast and banded application, as well as incorporation by injection and the flexible harrow. Ammonia volatilization from all treatments could be measured simultaneously, and at ambient climatic conditions by an indirect, open measurement technique. The experiment was repeated four times. Due to varying weather conditions and treatment effects, cumulative NH 3 volatilization from the slurry during the first 48 hours ranged from 4 to 90% of total ammoniacal nitrogen (TAN). Both separation and incorporation significantly decreased NH 3 losses, but only the combination of dry matter reduction and injection or harrowing reduced NH 3 volatilization to about 30% of TAN in all weather conditions. Banding alone did not efficiently conserve slurry N, but even enhanced NH 3 volatilization in wet conditions.

The mutual influence of slurry pH and volatilization processes on one hand, and the possibility of N conservation by the use of acidifying additives on the other, were investigated in static incubation experiments. The influence of the NH3 and CO2 volatilizations on slurry pH was studied by selectively supporting one or both processes. The addition of Ca2+ to slurry was compared to that of K+ and H+. The effects of Cl−, SO 4 2− and NO 3 − as corresponding anions of Ca2+ on slurry pH as well as NH3 and N2O emissions were tested. The slurry pH (7.4) increased during incubation. When CO2 volatilization was suppressed, the pH increase was reduced, and NH3 volatilization was cut down by 50%. Ca2+ additions hardly influenced the initial slurry pH, but reduced the pH increases and NH3 losses. Proton addition, in contrast, decreased slurry pH but did not decrease the subsequent pH rise. K+ had no effect on slurry pH and N losses. As compared to CaCl2, CaSO4 showed less effect on slurry pH and N losses. Ca(NO3)2 was nearly as effective as CaCl2 in preventing NH3 volatilization, but caused denitrification losses and elevated N2O production. Titration curves of the different slurry treatments were used to interpret the results of the incubation experiments. In a microplot field experiment the NH3 volatilization and slurry pH after surface application of slurry was measured. The acidifying and N conserving effects of Ca2+ and H+ additions were confirmed.

Auf der Basis einer Literaturstudie wird die Eignung von Biomüllkompost als N-Dünger sowie die Gefahr einer Umweltbelastung durch N-Verluste bei langfristiger Anwendung behandelt. Da nur wenige Arbeiten zu Biomüllkompost vorliegen, werden auch Untersuchungen zu verwandten organischen Düngern wie Müllkompost, Festmist u.a. ausgewertet. Die Ertragswirkung von Komposten im Vergleich zu Minderaldüngern ist gering, da N bei dem Kompostierungsvorgang in nicht pflanzenverfügbarer Form festgelegt wird. Ein Großteil des Kompost-N wird im Humusvorrat des Bodens gespeichert. Durch den Anstieg des N-Bodenvorrates steigt die Gefahr von N-Verlusten durch Mineralisation in der vegetationsfreien Zeit. Bei kombinierten Kompost- und Mineraldünger-N-Gaben werden gute Ernten erzielt. N-Bilanzen von Langzeitversuchen mit Stallmist zeigen dabei z.T. keinen Anstieg der N-Verluste gegenüber reiner Mineraldüngung. Möglicherweise ist eine mit mineralischer N-Düngung kombinierte Kompostdüngung eine die Bodenfruchtbarkeit und Ertragssicherheit steigernde und zugleich umweltverträgliche Verwertungsmöglichkeit von Biomüllkompost, doch besteht noch erheblicher Forschungsbedarf zur Klärung von Ausmaß und Form möglicher N-Verluste aus Kompost.