B. Amon

Emissions of NH3, N2O and CH4 from dairy cows housed in a farmyard manure tying stall (housing, manure storage, manure spreading)

Emission measurements from dairy cows housed in a tying stall were carried out with the aim of finding factors that influence the amount of emissions and means to reduce emissions. All sectors of animal husbandry were investigated. This enabled calculations of emissions for the whole management system including housing, storage and spreading of manure. Emissions during aerobic composting and anaerobic stacking of farmyard manure were compared. NH3 and N2O emissions from tying stalls for dairy cows are low (5.8 g NH3 LU−1 d−1, 619.2 mg N2O LU−1 d−1). Methane emissions from the animal housing are mainly caused by enteric fermentation. During storage and after spreading of farmyard manure substantial differences concerning NH3, N2O and CH4 emissions were observed with composted and anaerobically stacked farmyard manure. The compost emitted more NH3 than the anaerobically stacked farmyard manure. About one third of the NH3 emissions from the anaerobically stacked farmyard manure occurred after spreading. Total N losses were at a low level with both storage systems. Greenhouse gas emissions (N2O and CH4) were much higher from the anaerobically stacked farmyard manure than from the composted one. As these are ecologically harmful gases, they have to be considered when judging the form of manure treatment.

Greenhouse gas emissions from selected Austrian dairy production systems—model calculations considering the effects of land use change

The aim of this study was to analyze various Austrian dairy production systems (PS) concerning their greenhouse gas emissions (GHGE) in a life-cycle chain, including effects of land-use change (LUC). Models of eight PS that differ, on the one hand, in their regional location (alpine, uplands and lowlands) and, on the other hand, in their production method (conventional versus organic, including traditional and recently emerging pasture-based dairy farming) were designed. In general, the GHGE-reducing effect of a higher milk yield per cow and year in conventional dairy farming cannot compensate for the advantages of organic dairy production which requires lower inputs. This is shown both for GHGE per kg of milk and GHGE per ha and year of farmland. Especially when (imported) concentrates were fed, which had been grown on former forests or grassland, e.g. soybean meal and rapeseed cake, GHGE of conventional dairy farming rose due to the effects of LUC. GHGE per kg milk varied from 0.90 to 1.17 kg CO2-eq for conventional PS, while organic PS on average emitted 11% less greenhouse gases (GHGs), the values ranging from 0.81 to 1.02 CO2-eq per kg milk. Within each production method, PS with a higher milk output generally showed better results for GHGE per kg of milk produced than PS with a lower milk output. Nevertheless the latter showed clearly better results for GHGE per ha of land used, ranging from 5.2 to 7.6 Mg CO2-eq per ha and year for conventional PS and from 4.2 to 6.2 Mg CO2-eq per ha and year for organic PS. The results of this study emphasize the importance of a complete life-cycle assessment in the evaluation of impacts that dairy PS have on the climate.

Utilization of by-products from ethanol production as substrate for biogas production.

The aims of this work were to determine the specific biogas yields of steam-exploded sugarcane straw and bagasse as well as to estimate their energy potential under Brazilian conditions. Steam-explosion was carried out under different time and temperature conditions. The specific biogas yields were analyzed in batch-tests according to VDI 4630. Results have shown that steam-explosion pre-treatment increased the specific biogas yields of straw and bagasse significantly compared to the untreated material. The utilization of these by-products can contribute to 5% of the total energy consumption and thereby higher energy independence in Brazil. Further efforts in defining the optimum pretreatment conditions with steam-explosion as well as implementing this technology in large scale plants should be made.

Reclip:tom: Forschung zum Klimaschutz - Technische Möglichkeiten zur Emissionsminderung

The project reclip:tom sets up sector comprehensive emission prognoses up to the year 2050. Mitigation measures and their costs are proposed. Interactions within a sector and between the sectors are especially taken into consideration. This paper discusses the procedure for the agricultural sector and its interactions.