Bedeutung der Modellvalidität für die Ökobilanzierung von landwirtschaftlichen Produkten – Vergleich zweier Milchrindras-sen

In the experimental station of the Thünen-Institute of Organic Farming the dairy breeds Holstein-Friesian (SBT) and Red Holstein double usage (RBT) are kept in separate herds under identical conditions. By means of a material flow FARM-Model, designed with the life cycle assessment (LCA) and material flow software Umberto, an assessment from cradle to farm gate of standard environmental impact categories was undertaken. While the BH has a better environmental performance due to higher milk yields the results depend largely on used algorithms in the model. When benchmarking different farms in terms of environmental performance modeling uncertainty has to be taken into account

Phosphor-Bodenbilanzen von Grünland- und Ackerflächen auf einem ökologischen Milchviehbetrieb

Mineral phosphorus (P) fertilizers from fossil reserves are finite which puts agriculture at risk of losing soil fertility. This study calculates P soil balances of an organic dairy farm in Northern Germany to focus on potentials and variations in the farm P cycle. P flows were different between the years because yield levels and amount of manure application varied. Different plant species showed different P export which depended mainly on biomass export. This can also be seen as their site specific mobilization potential. The highest mean P export between 2010 and 2012 was measured with maize (mean 30.4, range 17.7-38.2 kg P ha-1 a-1) and grass-clover (mean 23.7, range 17.3-29.5 kg P ha-1 a-1). By grazing, permanent grassland showed a mean P mobilization from soil P of 15.9 kg ha-1 a-1. The annual soil P balance was -7.96 kg P ha-1 (range -6.16 to -9.3 kg P ha-1) at permanent grassland and -11.1 kg P ha-1 at arable land (range -1.5 to -17.7 kg P ha-1). Because of the high ranges it is reasonable to analyze a few years to get a better view on P flows at farms. High PCAL values from historical fertilizer inputs can be seen as a P source in short term and can especially be mobilized by permanent grassland. It is necessary to change the P flows into a more sustainable way before the P gap cannot be closed by soil reserves anymore and P deficit will limit plant growth

Auswirkungen der Berechnung der funktionellen Einheit in der Milchproduktion auf das Ergebnis von Ökobilanzen

Life cycle assessment (LCA) allows systematic comparisons of environmental performance between different products. The functional unit in LCA for milk production is typically set to 1 kg energy corrected milk. This does not however suffice as definition to allow for comparing different studies. The definition of reference flow can introduce a bias between organic and conventional farming systems. We strongly encourage to include definition of reference flow calculation, choice of algorithm for energy calculation as well as choice of energy content of milk in the communication of any results

Effects of temporarily reduced tillage in organic crop rotations on yield, earthworm biomass and development of weed pressure. First results of a case study from Schleswig-Holstein/Germany

Farming systems applying reduced tillage measures are expected to be beneficial for sustaining important soil functions (ecosystem services) and (soil)biodiversity. Furthermore a reduction in tillage intensity is connected to reduced need for energy and labour input. On the other hand waiving the plough is, especially in organic farming systems, suspected to lead to increased weed pressure and therefore decreases in yields. In this paper first results of a study on temporarily reduced tillage in organic crop-rotations are presented. Here the plough was set aside before drilling triticale at the end of four crop rotations, and expectable yields, earthworm biomass and weed pressure were investigated. First one-year-results, of the experiment on temporarily reduced tillage to triticale at the end of organic crop-rotations did not show consistent yield effects. Increase in weed dominance at harvest on sites without ploughing and the expected positive effect on earthworm biomass in spring could not be statistically secured

Welchen Einfluss hat der Weidegang auf das Tierwohl von Milchkühen? Erste Ergebnisse des Welfare Quality® Protokolls bei ganzjähriger Stallhaltung und Sommerweidegang

Grazing provides livestock better opportunities to act out their species specific behaviour compared to the restrictive stable conditions. Studies on the effect of grazing on animal welfare in dairy farming in Germany are rare and have not been conducted under the specific conditions of organic dairy farming. The aim of the present study was to examine the effects of grazing on animal welfare of dairy cows in organic and conventional farming based on the Welfare Quality® protocol for dairy cattle. In this paper, we present the initial evaluation of a comparison between zero grazing and summer grazing. The first results indicate an improvement in most welfare principles during the summer months for dairy cows with summer grazing, except for between winter and summer in zero grazing farms. In conclusion, grazing offers a great potential for improved animal welfare, while the benefitial effects of grazing are not guaranteed in event of suboptimal management

Eiweiß- und Energieversorgung in 34 konventionellen und ökologischen Milchviehherden Ergebnisse aus einem Netzwerk von Pilotbetrieben

For reasons of animal health, milk yield and for environmental issues an optimal supply of protein and energy for dairy cows is essential. The aim of this study is to examine potential protein and energy malnutrition and surplus in dairy herds. We present a comparison of the protein and energy supply between 18 conventional and 16 organic dairy herds. Initial results indicate an undersupply on energy in the first one hundred days of lactation in both the organic and conventional feeding regimes. It is easier to provide an adequate protein supply in conventional conditions in the first one hundred days than in organic ones. A balanced supply is guaranteed for a mere 21,3 % of the organic cows. In the second one hundred days this increases to 26,5 %, compared to 51,7 % in conventional ones. In high yielding organic dairy herds there is a shortage in energy and protein in the second one hundred days as well. In low yielding organic herds a surplus on protein over the whole lactation with possible negative effects on animal health and ammonia emissions is observed. Once more these first results demonstrate the difficulty of providing a balanced nutrition in organic dairy herds

Large variation in nitrogen efficiency among organic and non-organic farms

Agricultural production is requested to be environmental friendly and resource efficient. A literature review of farm surveys and prototype farm studies found that increasing use of N fertilizer and imported feed increased the yields and the productivity of dairy farms, but also increased the N-surplus. We studied the N-efficiency and cause of variation in organic and non-organic commercial dairy farms. Increased amount of purchased-N per ha farmland increased the farm N-surplus per ha on organic and non-organic farms. Increased amount of purchased-N tended to decrease N-efficiency, but not on non-organic farms. The correlation between the N-surplus per unit of produce and N-purchase was weak. The organic farms had lower N-surplus per ha than the conventional farms, had higher efficiency of imported nitrogen and lower N-surplus per unit of produce, leading to an overall better utilization of available N. Within organic and non-organic farm management, the variation in estimated N-efficiencies is larger than the differences between the averages of these two groups

Optimierungsansätze zur Verbesserung von Nachhaltigkeit, Ressourceneffizienz und Tierwohl in ökologischen und konventionellen Betrieben im Netzwerk Pilotbetriebe

In a network of organic and conventional pilot farms with dairy and/or arable production in Germany (www.pilotbetriebe.de) aspects of sustainability, resource efficiency, animal health and welfare and economic aspects are analysed. This is based on on-farm assessments and on whole farm modelling. In the first interdisciplinary workshops on the project farms results were presented and scenarios were developed in a participatory approach by scientists, consultants and farmers to improve N, P and land use efficiency as well as dairy health and welfare. Typical areas of action to optimize sustainability in these aspects were identified on the farms, e.g., complete accounting of manure N (N balance), enrichment of crop rotations with clover grass and cover crops (humus balance), improving forage quality (productivity, nutritional imbalances), improvement of housing conditions and grazing access (animal health and welfare). Systematic integration and detection of interconnectedness of environmental performance of production, animal welfare, resource efficiency and productivity result in a new quality in development of farm concepts

Biodiversity Impact Assessment of Land Using Processes in the Supply Chain of Passenger Cars

Biodiversity loss has been recognized as one of the major global challenges of current and future society. Land-using processes have been found to be among the most important direct drivers for biodiversity loss. Life cycle assessment (LCA) has established itself as a standardized tool for measuring environmental impacts of products and processes. However, there is no clear consensus on the integration of land-use related impacts on biodiversity in LCA-frameworks due to a lack of methodological guidance, suitable datasets and experience in real-world applications. Closing these gaps could enable political institutions and companies to determine the effects of their products on biodiversity over the entire life cycle. In this study, a method, aiming to integrate the biodiversity impact in LCA, is successfully applied on a product with a complex supply chain. A suitable dataset of the material composition of a modern electric vehicle adapted to match the specifications of the Volkswagen ID.3 is developed. To estimate land use requirements of five important metals a GIS-based approach is elaborated. 164 mines covering an area of 4,123 km2 in eight different countries are inspected by means of satellite imagery and enhanced with data from industrial reports to build suitable datasets for the impact assessment. Based on these datasets, five unit processes are developed and applied to the VW ID.3 model. The results indicate that cobalt, lithium and copper account for the major biodiversity impact among the assessed metals. A scenario analysis reveals a biodiversity impact reduction potential of at least 23%. To the best knowledge of the authors, this study presents the first biodiversity impact assessment in the supply chain of a modern vehicle. The datasets, the application example and the workflow developed and applied in this study can serve as methodological guidance to support LCA-practitioners and researchers in the integration and application of biodiversity impacts in LCA-frameworks and LCA-studies. Thus, it supplements existing indicators in a meaningful way and makes them usable for future LCA studies