Browsing by Subject "Lineare Optimierung"

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An economic analysis of the implementation options of soil conservation policies
(2008) Schuler, Johannes; Dabbert, Stephan
The objective of this study is to analyze the economic and agricultural aspects of the implementation of soil conservation programmes and to suggest appropriate measure-instrument combinations for efficient soil conservation as a decision support for the implementation of soil conservation policies. Emphasis is given to the resource and institutional economics of soil conservation. In the empirical part, the efficiency of policy options is analysed using the example of a region in north-eastern Germany based on model calculations. After an introduction to the topic of soil functions and soil degradation definitions, the implementation concepts for soil protection measures at the international and national level are described. Based on the theoretical economic analysis of soils as a natural resource, the existing property rights, the public good characteristics of soils and the resulting externalities lead to the conclusion that market failure does exist. Therefore, the non-market coordination of soil use is justified. A cost-effectiveness analysis was derived based on the theory of ?safe-minimum-standard? for the appropriate assessment of the implementation options of soil conservation policies. A fuzzy-logic-based method, which is based on an expanded Universal Soil Loss Equation approach (USLE), was applied for the assessment of soil erosion risk in the sample region. The approach considers both the natural conditions and the characteristics of the cropping practice. The very detailed description of the cropping practices allowed for the specific assessment of erosion relevant effects. This, in combination with the high detail site descriptions provided this study with a very precise regional approach. The regional decision-support system MODAM (multi-objective decision support tool for agro-ecosystem management) was applied for the assessment of the economic and environmental impacts of different policy options. The policy scenarios examined include a CAP reform scenario with decoupled payments in accordance with the proposed conditions of the year 2013. This scenario was used as the reference scenario for the other possible scenarios of soil conservation policies. The three main scenarios for the policy options are 1) a non-spatially oriented, 2) a spatially-oriented incentive programmes for reduced tillage practices and 3) a regulation scenario that prohibits the cultivation of highly erosive crops (row crops) on erodible soils. The prohibition of row crops on highly erodible soils led both to lower on-farm costs and lower budget costs in comparison to the incentive programmes for reduced tillage. All three scenarios had comparable reduction in soil erosion. Based on the modeling results the ban on row crops on highly erodible sites is therefore the preferable option in terms of the cost-effectiveness ratio. The inclusion of transaction costs in this study helps expand the scope of policy analysis, for the total costs of a policy would be underestimated if only the budget costs for the direct payments to farmers were considered. Transaction costs understood as a cost for the (re-) definition and implementation of property rights can reach substantial amounts and reduce the total efficiency of a policy. The results of the qualitative analysis of the transaction costs of the study policy options also supported the option of row crop regulation on highly erodible soils. A model that serves as decision support for both the economic and agricultural aspects of soil conservation had been successfully developed in this study. Different policy options were analysed for a cost-effective solution of soil conservation programmes. Based on the final discussion on the involved transaction costs, the regulatory approach (a spatially-focussed ban on row crops) was shown to be the most cost-effective option with potentially lower transaction costs. The main criteria for a cost-effective policy design are high efficiency in both the agricultural measures (practices) and the spatial correlation between the programme area and the high erosion risk areas. Incentive programmes in combination with less effective agricultural practices showed a worse cost-benefit ratio for the sample area than the regulation approach, which is based on more effective agricultural practices.
Nachhaltiger Anbau von Bioenergie : eine ökonomisch-ökologische Analyse für die Landwirtschaft in Baden-Württemberg
(2012) Konold, Angelika; Zeddies, Jürgen
The aim of this thesis is on the one hand to estimate the potential of energy crop production for CO2-sequestration in Baden-Württemberg. On the other hand the focus lies on the interactions that arise from the implementation of optimized na-ture conservation measures with the land management on regional level. For this the existing economic-ecological regional model EFEM (Economic Farm Emission Model), based on linear programming, is further developed. The calculations are made on farm level and are extrapolated on regional level. The model is calibrated on the database for the years 2001-2005 and the so modeled Reference_2003 than is projected to the year 2015 (BAU_2015), this to evaluate the model results without the influence of the great changes in agricultural policy in the last years. Based on the modeled situation for the year 2015 further scenarios are defined that differ in the expansion of energy cropping and nature conservation measures. In the ?biomass scenarios? only the legal nature requirements have to be met while in the corresponding ?conservation scenarios? restrictions that are optimal from a nature conservation point of view, must be considered. The sensitivity analyses for selected parameters proved that the model results have sufficient stability to make reliable statements about synergy effects and conflicts between the expansion of energy crop cultivation and requirements for natural conservation. Altogether it could be shown that with the used model approach interactions be-tween the cultivation of energy crops and nature conservation are represented sufficiently and the objectives of energy and climate policy are compatible.
Ökonomische Bewertung regionaler Wettbewerbspotentiale verschiedener landwirtschaftlicher Biomassen im Rahmen der Bioökonomie unter besonderer Berücksichtigung Baden-Württembergs
(2020) Petig, Eckart; Bahrs, Enno
The finite nature of fossil resources and climate change pose major challenges to the global society and require a comprehensive transformation of the current economic system. One important aspect of this transformation, also known as bioeconomy, is the transition from a fossil-based to a bio-based supply of raw materials. In this context, agricultural production represents an important supplier of raw materials, which in Germany is already characterized by a strong competition for the scarce land. The scarce land is a major challenge of the expansion of the use of agricultural biomass for the bioeconomy. Accordingly, the derivation of the potential of agricultural biomass for bioeconomy requires consideration of the tradeoffs between various utilization paths. In this context, economic models can be valuable methods, which on one hand are able to depict the trade-offs of different value chains and can, on the other hand, incorporate the uncertainty by developing suitable scenarios. The aim of this thesis is the evaluation of the potential of different agricultural biomasses for the bioeconomy and to analyze the associated effects on agricultural production structures in Baden-Wuerttemberg. In chapter 2 the potential of grassland as a biogas substrate is evaluated, which might be important for the bioeconomy in the future. Due to the more complex harvesting process and partly unfavorable production conditions, grassland has higher production costs compared to arable biogas substrates. The consideration of iLUC Factors with high prices for GHG emissions could improve the competitiveness of grassland to such an extent that it is competitive with the production of biogas substrates on arable land. However, silage maize is often the more favorable biogas substrate in many respects, as chapter 3 shows by means of a site modeling for biogas plants in Baden-Wuerttemberg. In chapter 4 and 5 the potential of straw for energetic and material use is analyzed. These investigations are based on the combination of EFEM with the techno-economic location optimization model BIOLOCATE. The results clearly show the interaction between the economies of scale and the rising raw material supply costs. On the one hand, the average investment costs decrease with increasing plant size, but on the other hand the raw material costs increase, because the transport distances increase and an increasing demand for biomass results also in higher market prices. Additionally, the results show that straw can make a fundamental contribution to the bioeconomy by providing regional bioenergy and as feedstock for material value chains. However, even the use of by-products can have effects on cultivation structures and thus, reduce the production of agricultural biogas substrates, among other things. In Chapter 6 the effects of macroeconomic expansion paths of the bioeconomy on agricultural production structures in Baden-Wuerttemberg are investigated. For this purpose, the results of an iterative model coupling between the agricultural sector model ESIM and the energy sector model TIMES-PanEU of four bioeconomic scenarios are scaled down from national level to regional and farm level using EFEM. The results show different impacts on farm types and thus illustrate the advantages of a differentiated analysis of the expansion of the bioeconomy. Therefore, farms with mainly extensive production methods such as suckler cow husbandry do not profit from the expansion of the bioeconomy due to unfavorable production conditions, while especially large arable farms in fertile regions would benefit disproportional more than the average. Basically, the results reveal limits to the mobilization of additional biomass potential. The reason for this is the already high cultivation intensity of agricultural production in Germany, in which the expansion of one production restricts production of another due to competition for the limited agricultural land. For grassland, the results show that the decline in grassland-based cattle farming and unfavorable economic conditions can lead to a significant increase of unused grassland. Grassland thus presents itself as a promising resource for biomass production for the bioeconomy, as it can provide important ecosystem services (e.g. biodiversity) in addition to the provision of raw materials. However, a political framework has to be established that promotes ecological services accordingly. Finally, in chapter 7 additional research needs are identified, which include further development of the methodological approach. These comprise an extension of the analysis by macroeconomic models to integrate interactions with the material use in a more detailed way. Furthermore, an integration of ecological parameters is necessary for a holistic analysis in the context of bioeconomy.
Simultaneous lotsizing and scheduling - extensions and solution approaches
(2018) Wörbelauer, Martin; Meyr, Herbert
The present thesis focuses on simultaneous lotsizing and scheduling. A comprehensive review of the literature is presented in which the historical development of the subject and the current research gaps are, based on a classification scheme, described. Additionally, a review focusing on so-called „secondary resources“ (e.g., setup operators or raw materials), which are considered alongside the primary production resource, is provided. The insights on different types of secondary resources help to develop a new model formulation generalizing and extending the currently used approaches, which are specific to certain settings. Some illustrative examples demonstrate the functional principle and flexibility of this new formulation which can thus be used in a wide range of applications. Finally, a new heuristic to solve large-scaled simultaneous lotsizing and scheduling problems is presented. The heuristic creates a modified multi-line master problem by aggregating products into groups. The resulting problem is less complex and its solution can be used to define single-line sub problems. These sub problems are solved by heuristics present in the literature and the results are then combined to form a solution to the original problem. Numerical tests show the applicability of the aforementioned approach to solve problems of practical relevance.
Smallholder milk production in the Punjab of Pakistan and the evaluation of potential interventions
(2007) Teufel, Nils; Gall, Christian
The potential offered by milk production and marketing to increase rural income has long been recognised. Yet, milk production by smallholder households, the great majority of the 4.1 million households with dairy animals in the Punjab of Pakistan, has remained practically unchanged. In order to facilitate improved decisions on the allocation of limited development resources, this study analyses smallholder milk production, determines the effects of a variety of technical improvements and evaluates these by their household effects. For this, a linear programming model simulates household decisions based on identified objectives, recorded resources and technical characteristics. Multiple objectives are considered through compromise programming. Ten improvement scenarios are formulated. These include the introduction of new feeds (maize grain, commercial concentrates, molasses and hybrid sorghum), improved reproductive performance (reduced age at first calving and reduced inter-calving period), improved veterinary health (reduced mortality of calves and of adult females) and the introduction of genetically improved animals, through selective breeding (buffalo and cattle) or crossbreeding (cattle). Model data were collected during a cross-sectional survey of 322 randomly selected households and a 13-month longitudinal survey of 64 specifically selected smallholders in the central region of the irrigated Punjab of Pakistan. Cluster analysis identifies seven household classes in the cross-sectional sample. The three largest are considered in the model, characterised as "smallholders with marginal land resources" (class 1), "smallholders with subsistence orientated milk production" (class 2) and "smallholders with market orientated milk production" (class 3). The classification is applied to the longitudinal survey sample by discriminant analysis, identifying 9, 23, and 31 households in classes 1 to 3, respectively. Herd sizes are similar in household classes 1 and 2, with 2.1 and 2.3 adult female buffaloes respectively, while 3.6 are kept in class 3. Only 0.5 adult female cattle are kept in all classes. Land availability is similar for classes 2 and 3 (2.4 ha), but only 1.0 ha in class 1. Cropping patterns are dominated by wheat and rice. Berseem (Egyptian clover) and sorghum plus maize are important fodder crops. The nutrient supply calculated from feeding records corresponds well to estimated livestock nutrient requirements. Nevertheless, feed shortage periods in spring and early winter demand attention. Feed energy constrains livestock nutrition throughout the year in all classes. In addition to maximising family income, households also aim at maintaining their welfare against negative shocks. Also, opportunity costs of family labour are difficult to determine. Thus, maximising farm income and livestock assets (for insurance) as well as minimising loan requirements and family labour use are defined as model objectives in this order of importance. Food requirements are formulated as constraints. The activity levels produced by the base household model correspond well to longitudinal survey data. However, milk marketing is not only determined by the milk price but also by the reliability of marketing systems. Therefore, the milk price within the model is reduced to simulate recorded milk marketing levels. The price reduction is interpreted as the ?perceived? risk associated with milk marketing at village level. Model results of the ten improvement scenarios show positive effects for most interventions. Cheap high-energy feeds ("molasses", "hybrid sorghum") provide the greatest benefits for all classes. Increasing annual milk output ("inter-calving period", "selective breeding") is mainly effective in households selling substantial amounts of milk. Reducing replacement requirements ("adult mortality", "age at first calving") does not considerably improve the attractiveness of milk production. High-value concentrates (?maize grain?, ?commercial concentrates?) are unattractive as long as alternatives (e.g. wheat grain) are self-produced at current opportunity costs of land and labour. Finally, reducing calf mortality has practically no effect and crossbred cattle are only attractive under good marketing conditions with effective institutions. Including only income as objective indicates rising incomes when herd sizes are reduced in favour of cash crops. In a third model version, the effects of higher "perceived" milk prices simulate reactions to improved milk marketing. Despite considerable improvements in the adjusted base model, low-cost feeds still manage to produce considerable benefits. The study shows that introducing targeted interventions, such as providing cheap high-energy feeds, to smallholder milk production and improving market access are effective approaches for decreasing rural poverty.
Socio-economic benefits and limitations of irrigated family farming in Brazil’s semi-arid region
(2016) Hagel, Heinrich; Doluschitz, Reiner
Seit jeher wird der semi-aride Nordosten Brasiliens von schwerwiegenden Dürren heimgesucht. Schriftliche Überlieferungen reichen bis in die Zeit der Kolonialisierung des Landes gegen Ende des 17. Jahrhunderts zurück. Gegen Ende des 19. Jahrhunderts begann Brasiliens Regierung mit dem Bau größerer Reservoirs, um den Bewässerungslandbau zur Sicherung der Lebensgrundlage der ländlichen Bevölkerung zu fördern. Erst jedoch die Errichtung zahlreicher Staudämme und Stauseen zur Elektrizitätsgewinnung seit den 1960er Jahren ermöglichte die großflächige Verbreitung der Bewässerungslandbaus, wie im Falle des Rio São Francisco, an dessen Mittellauf zahlreiche Bewässerungsgebiete etabliert wurden. Trotz einer positiven wirtschaftlichen Entwicklung und beachtlichen Fortschritten in der Armutsbekämpfung leben große Teile der Landbevölkerung weiterhin in prekären Verhältnissen. Ziel dieser Dissertation war zunächst eine detaillierte Analyse der vorhandenen landwirtschaftlichen Produktionssysteme und der sozio-ökonomischen Situation der Bewässerungslandbau betreibenden Familienbetriebe entlang des Mittellaufs des Rio São Francisco. Zudem wurden die natürlichen, wirtschaftlichen und sozialen Be-schränkungen sowie die Vorzüge des Bewässerungslandbaus identifiziert. Modelle einer effizienteren Ressourcennutzung wurden erstellt und bewertet. Mit Hilfe dieser Modelle wurde schließlich der Einfluss sich verändernder Produktions- und Rahmenbedingungen auf den Bewässerungslandbau evaluiert. Als Datengrundlage dien-ten die Ergebnisse aus 60 Experteninterviews und einer Farm-Haushaltsbefragung mit 193 zufällig ausgewählten kleinbäuerlichen Familienbetrieben, ergänzt durch Sekundärdaten. Zeitreihen wurden mittels Regressionsanalyse, qualitative Daten mittels Inhaltsanalyse und die Daten der Farm-Haushaltsbefragung mittels Regressionsanalyse und Varianzanalyse ausgewertet. Einzelbetriebliche Optimierungsmodelle zu einer effizienteren Ressourcennutzung wurden mit Hilfe von linearer Programmierung optimiert. Veränderte klimatische oder infrastrukturelle Rahmenbedingungen stellten sich als große Risikofaktoren für die Produktivität des kleinbäuerlichen Bewässerungslandbaus heraus. Bereits im Untersuchungszeitraum, einer Phase mit sehr hohen Erzeugerpreisen, erzielte knapp die Hälfte der interviewten Haushalte ein landwirtschaftliches Betriebseinkommen unterhalb des gesetzlichen Mindestlohns. Unzureichende Infrastruktur, mangelhafter Marktzugang, volatile und von Zwischenhändlern bestimmte Erzeugerpreise, mangelhafte Kooperation zwischen den Kleinbauern, exzessive Bewässerung und Ausbringung von Pflanzenschutzmitteln und schließlich man-gelhafte Erfahrung im intensiven Obst- und Gemüsebau wurden als wesentliche Be-schränkungen des kleinbäuerlichen Bewässerungslandbaus in der Studienregion identifiziert. Das Fehlen landwirtschaftlicher Beratung verschärfte viele dieser Probleme. Auf der anderen Seite waren eine geeignete Wahl der angebauten Kulturen und eine großzügigere Flächenausstattung die Hauptfaktoren für wirtschaftlichen Erfolg. Innovative, geschäftstüchtige Kleinbauern, darunter einige mit geringen verfügbaren Flächen, verdeutlichten dennoch das Potential des Bewässerungslandbaus zur Bekämpfung der ländlichen Armut in der Studienregion. Die Wiederaufnahme landwirtschaftlicher Beratung, kombiniert mit Bildungsangeboten zur Steigerung des Humankapitals insbesondere bezüglich landwirtschaftlicher Betriebslehre und Kooperati-onsformen zwischen Kleinbauern, kann wesentlich zu einer Verbesserung der landwirtschaftlichen Produktion und der Lebensbedingungen der ländlichen Bevölkerung in der Studienregion beitragen. Der exzessiven Bewässerung können ein volumetrischer Wasserpreis und die Förderung effizienterer Bewässerungsmethoden entgegenwirken.