Browsing by Subject "Life cycle assessment (LCA)"

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Identifying loss and waste hotspots and data gaps throughout the wheat and bread lifecycle in the Fars province of Iran through value stream mapping
(2023) Ghaziani, Shahin; Dehbozorgi, Gholamreza; Bakhshoodeh, Mohammad; Doluschitz, Reiner
Reducing wheat and bread loss and waste is crucial for ensuring global food security and sustainability. The importance of reducing wheat and bread loss is particularly significant in Iran, where wheat is a staple crop and a vital component of the country’s food security. A value stream mapping study was conducted to identify loss and waste hotspots and critical data gaps along the wheat and bread lifecycle (WBL). In October 2018, 14 experts were surveyed in Fars province, Iran’s second-largest wheat producer. The study presents a detailed cradle-to-grave overview of WBL and identifies farms, foodservice, and households as the loss and waste hotspots. The results revealed significant data gaps regarding on-farm wheat loss and household bread waste. Additionally, although data exist in other segments of WBL, they are not readily accessible nor utilized to report loss and waste, highlighting the need for transparency within the WBL system and further research to compile existing data and analyze wheat and bread loss and waste. Other researchers can employ the holistic approach of the present study to investigate loss and waste throughout the lifecycle of other food items in different geographical contexts. The methodology adopted in this study offers advantages for defining the scope of research in lifecycle assessment and circular economy studies.
Implications of large‐scale miscanthus cultivation in water protection areas: A Life Cycle Assessment with model coupling for improved policy support
(2022) Weik, Jan; Lask, Jan; Petig, Eckart; Seeger, Stefan; Marting Vidaurre, Nirvana; Wagner, Moritz; Weiler, Markus; Bahrs, Enno; Lewandowski, Iris; Angenendt, Elisabeth
Two major global challenges related to agriculture are climate change and the unbalanced nitrogen cycle. For both, national and international reduction targets have been defined to catalyse policy support for more sustainable farming systems. Miscanthus cultivation in water protection areas has been proposed as a contribution to achieving these targets. However, a thorough understanding of the underlying system dynamics at various spatial levels is required before recommendations for policy development can be provided. In this study, a model framework was established to provide economic and environmental indicator results at regional and sub‐regional levels. It presents a consequential Life Cycle Assessment coupled with an agro‐economic supply model (Economic Farm Emission Model) that simulates crop and livestock production, and an agricultural hydrology model (DAISY) that assesses effects on the nitrogen cycle. The framework is applied to Baden‐Württemberg, a federal state in southwest Germany with eight agro‐ecological regions. Scenarios investigating the differences between mandatory and voluntary miscanthus cultivation were also explored. While the results show the high potential of miscanthus cultivation for the reduction of greenhouse gas emissions (−16% to −724%), the potential to reduce nitrate leaching (−4% to −44%) is compromised in some sub‐regions and scenarios (+4% to +13%) by substantial effects on the crop rotation. Furthermore, the cultivation of miscanthus reduces gross margins in most sub‐regions (−0.1% to −9.6%) and decreases domestic food production (−1% to −50%). However, in regions with low livestock density and high yields, miscanthus cultivation can maintain or increase farmers' income (0.1%–5.8%) and improve environmental protection. The study shows that the heterogeneity of arable land requires a flexible promotion programme for miscanthus. Voluntary cultivation schemes were identified as most suitable to capture sub‐regional differences. Policies should address the demand for miscanthus, for example, support the development of regional value chains, including farmers, water suppliers and the biobased industry.
Methodological approaches for assessing the environmental performance of perennial crop-based value chains
(2017) Wagner, Moritz; Lewandowski, Iris
In a developing bioeconomy, the demand for biomass for industrial purposes is expected to increase significantly. This demand needs to be met in a sustainable way and without compromising food security. With this goal in mind, resource-efficient lignocellulosic crops, such as perennial energy grasses, are often cited as a biomass source with low negative impacts on the environment. Under European conditions, miscanthus is the leading perennial energy grass because of its high biomass and energy yield potential. It is a C4 plant, which achieves dry matter biomass yields of up to 20 Mg ha−1 yr−1 when harvested in later winter, and up to 30 Mg ha−1 yr−1 when harvested green in October. Currently the main utilization route of miscanthus is direct combustion for heat generation, but the biomass can also be used for various other applications, such as biofuels and insulation material. Several studies have analysed the environmental performance of perennial crop-based value chains, but most of these only assessed the Global Warming Potential (GWP). However, the GWP alone is not an adequate indicator for the holistic assessment of the environmental performance of such value chains. In addition, these studies often used generic data and applied varying assumptions, which makes a comparison of different value chains difficult. The main goal of this thesis is to draw up recommendations for future assessments of the environmental performance of perennial crop-based value chains. For this purpose, five research objectives were formulated: 1) to identify the key parameters influencing the environmental performance of perennial crop-based value chains; 2) to analyse which impact categories are most relevant when assessing the environmental performance; 3) to assess the differences between various perennial-crop based value chains; 4) to assess the environmental performance of the utilization of marginal land to grow perennial crops for industrial purposes; and 5) to analyse and compare the environmental performance of annual and perennial crops in the example value chain ‘biogas production’. To achieve these research objectives, the environmental performance of several perennial crop-based value chains was analysed in various impact categories applying the same underlying assumptions and using field data obtained under ceteris paribus conditions. The analysis was carried out using the globally recognised Life Cycle Assessment (LCA) methodology, which is standardized by two ISO norms (14040/44). The results revealed that biomass yield is one of the most important parameters influencing the environmental performance of perennial crop-based value chains. An increase in yield of 50%, for instance, leads to an increase in carbon mitigation potential in a comparable range (46%). Furthermore, the marked influence on the environmental impact mitigation potential of both fertilizer-induced emissions and selection of the reference system was demonstrated. For example, if the reference system is changed from light fuel oil to natural gas, the substituting by heat generated from the combustion of miscanthus biomass increases the net impact in the category ‘particulate matter formation’ by 220%. The relevance of different impact categories was analysed for various perennial crop-based value chains using a normalisation approach. The results clearly indicated that a holistic assessment of the environmental performance of perennial crop-based value chains should at least include the impact categories ‘marine ecotoxicity’, ‘human toxicity’, ‘agricultural land occupation’, ‘freshwater eutrophication’ and ‘freshwater ecotoxicity’. In future assessments, it is recommended to include the impacts of land-use on both biodiversity (using species richness as an indicator) and soil quality (using SOM as an indicator). The comparison of the environmental performance of different perennial crop-based value chains revealed clear environmental advantages of the cascade use of biomass. An example is the production of miscanthus-based insulation material, which is first used as a building material and then incinerated to generate heat and electricity. The results also demonstrate that, despite low biomass yield on marginal land, miscanthus-based value chains have a substantial environmental impact mitigation potential when substituting a fossil-based reference system. Furthermore, the comparison of annual and perennials crops as biogas substrates showed that perennial crops, and in particular miscanthus, have a considerably better environmental performance in the impact categories ‘climate change’ (up to -73%), ‘fossil fuel depletion’ (up to -79%), ‘freshwater eutrophication’ (up to -69%), ‘marine eutrophication’ (up to -67%), and ‘terrestrial acidification’ (up to -26%). In all four studies included in this thesis, it was observed that the data used for the biomass cultivation in particular, such as yield and fertilizer-induced emissions, have a considerable influence on the environmental performance. This data is highly site- and crop-specific and is strongly dependent on the agricultural management system applied. Based on the results of this thesis, the common practice of using generic data in assessments of the environmental performance of perennial crop-based value chains should be rejected. In order to obtain realistic results, the use of site- and crop-specific data is highly recommended.
Die Ökobilanz zur Abschätzung von Umweltwirkungen in der Pflanzenproduktion - dargestellt anhand von Praxisversuchen zur konservierenden Bodenbearbeitung und von unterschiedlich intensiv wirtschaftenden konventionellen Betrieben
(2003) Arman, Beate; Claupein, Wilhelm
In the agricultural field difficulties in life-cycle assessment result from the fact that the methods of life-cycle assessment were developed in techno-industrial production. Agricultural production, however, differs from industrial production in that it depends more strongly on natural resources and, moreover, has a direct influence on them. Hence, apart from preparing data for the used production goods, the expansion of environmental impact categories to include specific effects from agriculture is focused on in the adaptation of ecobalances as an agricultural method. Among others deficiencies here include the balancing of effects in agriculturally utilized soil. The ecobalances at hand were carried out with two different goals in mind. For one, the impact of conventional and conservational cultivation methods were to be balanced. The goal of this ecobalance was to show whether life-cycle assessment have adequate selective power in order to be used as a decision criterion in the optimisation of cultural methods and their environmental impact. For another, the intensity of cultivation of three agricultural enterprises was compared. It was to be shown here whether life-cycle assessment can provide transparency as to the environmental effects of various production methods, which would enable the consumer to obtain information on the environmental relevance of these methods. A further goal of this work was the development of a method for the recording of effects on the soil in life-cycle assessment. The examined farms are situated in the Hohenlohe region and were integrated in the subproject "Conservation Tillage" of the "Cultural Landscape Hohenlohe" project group. In order to balance soil working methods, the three methods plow, cultivator and mulch sowing were examined. The data was obtained from two test fields with the same crop rotation on one of the farms. Balancing of the intensity of cultivation was carried out on three conventionally working farms using varying levels of fertilizer, crop protectants and tillage. The balanced crop rotation of the three farms did not vary (sugar-beets, winter wheat, winter barley). When developing methods for balancing environmental effects on agriculturally utilized soil three aspects were decisive in the selection of balanced effects: 1. What soil properties are there? 2. Which of these properties are influenced directly by cultivation measures? 3. For which properties are relevant negative effects caused by agriculture known? Based on the indicated methods the impact was assessed for the following soil properties: - Soil depth is influenced by soil loss. Soil loss was calculated with the universal soil loss equation. - Impact on the nutrient content was assessed with the help of a nutrient field balance, humus content with the help of a humus balance. - Variations in soil density caused by loading were assessed with the help of the weighted soil load. - Soil life is affected by pollutant input, modelling of the effect potential was carried out with the help of the Critical-Surface-Time model. All in all the results show that in order to differentiate between the tillage variants with respect to their environmental impact, it is necessary to also consider effects on the soil. Comparison of the farms showed that life-cycle assessment can reflect the environmental relevance of different cultivation intensities and can make them visible for the consumer.
On the interplay of local versus global environmental and economic performance of Swiss alpine dairy farms
(2017) Repar, Nina; Doluschitz, Reiner
This cumulative dissertation consists of a general introduction (Chapter 1), three scientific papers (Chapters 2, 3 and 4) and a general conclusion (Chapter 5). The first peer-reviewed paper presented in Chapter 2 is of a conceptual nature. Based on a comprehensive and systematic review of the farm-level environmental performance indicators found in scientific literature, it shows that several of these indicators are inconsistently defined and inappropriate for the purpose of farm environmental performance assessment. This is due to the lack of conceptual considerations behind their definition. In the second step, starting from the environmental sustainability concept at macro level, the paper develops conceptual considerations on how to implement this concept at farm level into theoretically sound and consistent indicators of farm environmental performance. Based on the environmental sustainability concept viewed from an ecological perspective and on the associated ecosystem’s carrying capacity (constraint) concept, it distinguishes between the carrying capacity of the global ecosystem and that of the local ecosystem. Relying on this distinction, it proposes to differentiate between the global and local environmental performance of a farm. Whereas farm global environmental performance relates the cradle-to-farm gate (i.e. off- and on-farm) environmental impacts to the biophysical farm output, farm local environmental performance focuses on local on-farm environmental impact generation and relates it to the local on-farm area. The second peer-reviewed paper (Chapter 3) consists in an empirical application of the framework developed in Chapter 2. This application was carried out for a sample of 56 Swiss dairy farms, for which very detailed and comprehensive cradle-to-farm gate life cycle assessments (LCAs) were conducted. Farm global environmental performance was assessed as the farm digestible energy output for humans per unit of cradle-to-farm gate environmental impact. Farm local environmental performance was measured by the on-farm land area per unit of on-farm environmental impact. The paper investigates the relationships within the environmental performance dimension (i.e. between farm global and local environmental performance), and between the environmental and economic performance dimensions. The results showed the complexity of the relationships between farm global and local environmental performance. Trade-offs occurred more frequently than synergies, implying that an improvement in farm global environmental performance regarding one environmental issue will likely lead to a deterioration in farm local environmental performance regarding at least one other issue, and vice versa. These trade-offs highlight the challenging and complex nature of the improvement of the environmental sustainability of farming and provide clear evidence that farm environmental performance cannot and should not be reduced to a single “one size fits all” indicator. Our work furthermore showed the existence of synergies between farm global environmental and economic performance. The third peer-reviewed paper (Chapter 4) relies on the same dataset as used in Chapter 3. It investigates different structural, farm management, socio-demographic, technological and natural-environment-related determinants of the economic and environmental performance of dairying. It aims to identify the factors with the potential to simultaneously improve farm global environmental, local environmental and economic performance. The results revealed the existence of some factors presenting synergies and several factors showing trade-offs in the enhancement of these three dimensions of the sustainable performance of a farm. Organic farming, higher agricultural education level of the farm manager, the production of silage-free milk, and also, however to a weaker extent, full-time farming, larger farm size and a lower intensity of cattle concentrates use were identified as factors that allow global environmental, local environmental and economic performance to be improved simultaneously. More generally, the promotion of farm global environmental performance and farm economic performance was shown to be synergetic whereas the enhancement of farm global and local environmental performance turned out to be mostly antinomic. The core implications and related recommendations derived from the findings of this work are twofold. First, the conceptually correct measurement of farm environmental performance imperatively requires (i) the separate implementation of global and local environmental performance indicators as proposed in the framework and (ii) the consideration of both global and local dimensions to avoid environmental problem shifting from local to global scale and vice versa. This is especially necessary as the empirical application for Swiss alpine dairy farming found several trade-offs between farm global and local environmental performance. This empirical finding has far-reaching implications, especially if it is to be confirmed for other types of farms and other countries. The second core finding of this dissertation relates to the possibilities for improving the environmental and economic sustainability of Swiss alpine dairy farming. This work showed that there are some factors, namely organic farming, higher agricultural education level of the farm manager, the production of silage-free milk, and also, however to a weaker extent, lower intensity of concentrates use, larger farm size and full-time farming, which allow farm global environmental, local environmental and economic performance to be improved simultaneously.