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Now showing items 51-60 of 158
Aufsatz
Fusion of Ultrasonic and Spectral Sensor Data for Improving the Estimation of Biomass in Grasslands with Heterogeneous Sward Structure
(2017-01-21)
An accurate estimation of biomass is needed to understand the spatio-temporal changes of forage resources in pasture ecosystems and to support grazing management decisions. A timely evaluation of biomass is challenging, as it requires efficient means such as technical sensing methods to assess numerous data and create continuous maps. In order to calibrate ultrasonic and spectral sensors, a field experiment with heterogeneous pastures continuously stocked by cows at three grazing intensities was conducted. Sensor ...
Dissertation
Design of a decentralised camel milk processing plant with integration of renewable energy supply
(2020)
Der Milchsektor trägt zu ca. 4% zum Bruttoinlandsprodukt (BIP) in Kenia bei und ist der größte Teil des Agrarsektors. Kenias Kamelmilch spielt eine wichtige Rolle bei der Deckung des Ernährungs- und Wirtschaftsbedarfs in den ariden und semiariden Ländern (ASALs). Trotz dieser Bedeutung gibt es nur wenige Informationen über die Konservierungstechnologien und langlebige Milchprodukte wie Kamelmilchpulver. Außerdem zeichnen sich ASALs durch eine hohe Sonneneinstrahlung aus, die für die Konservierung von Kamelmilch genutzt ...
Dissertation
Use of organic wastes of Agave processing for bioenergy production
(2018)
Der organische Reststoff, welcher bei der Verarbeitung der Agave S. anfällt (Mezcal-Schlempe), ist aufgrund der hohen Anteile an organischer Substanz, anorganischen Salzen und anderer Inhaltstoffe ein umweltschädlicher Rückstand, der nicht ohne Vorbehandlung in Gewässer oder Böden gelangen darf, ggf. aber für die Bioenergieerzeugung genutzt werden könnte. Im Rahmen dieser Arbeit wurde daher unter Laborbedingungen die Eignung dafür durch drei Versuche zur anaeroben Vergärung und zwei zu mikrobiellen Brennstoffzellen ...
Aufsatz
Using Grass Cuttings from Sports Fields for Anaerobic Digestion and Combustion
(2017-03-18)
Sports fields provide a recreation space for citizens, but also generate grass biomass, which is cut weekly during the main seasons and therefore could be used in energy generation (combustion or anaerobic digestion). To evaluate the technical suitability of the grass cuttings, silage was produced from four sports fields during one vegetation period and investigated for relevant properties. Potential methane yield was determined with batch tests. Mean methane yield was 291.86 lN·kg−1 VSadded (VS, volatile solid). ...
Dissertation
Challenges to ecosystem services of sustainable agriculture in West Africa
(2020)
Food security is still sub-optimal in many parts of West Africa calling for more efficient agricultural practices in mitigating food insecurity. Some of the problems faced in West African agricultural systems are bottlenecks in ruminant livestock supply, inefficiency in commercial poultry production, and loss of arthropod diversity. These issues require proper integration of farming systems, demand the closing of nutrient cycles, need diversi cation of production, and require enhancement of ecosystem services. To ...
Dissertation
Entwicklung einer Robotik-Lösung zur Schneckenbekämpfung in der Landwirtschaft
(2020)
Schnecken sind bedeutende Schädlinge in der Landwirtschaft. Die Ausbringung von Schneckenkorn zur Schneckenbekämpfung als Verfahren nach dem Stand der Technik hat jedoch erhebliche Nachteile. Der Erfolg ist abhängig von der vorherrschenden Witterung und damit unsicher, zudem schadet es auch Nützlingen. Eine Robotik-Lösung zu Schneckenbekämpfung arbeitet wetterunabhängig und ist in der Lage, zwischen Schädlingen und Nützlingen zu unterscheiden.
Durch einen Feldversuch konnte gezeigt werden, dass Überfahrten eines ...
Dissertation
Development of Energy use Profiles, Reduction Concepts, and Implementation of Renewable Energies in the Central Ugandan Pineapple Processing Chains
(2020-02)
Pineapples, like all fruits, are highly perishable and require either immediate consumption or preservation. To make them more stable and add value, four major processing methods are being employed in Uganda, i.e. drying, munaanansi (local drink), wine, and juice making. Energy is one of the main inputs required to achieve any of the processing methods. The aim of this research was to develop energy use profiles, gain insights into energy use reduction options, and to evaluate the applicability of renewable energies ...
Dissertation
The potential of UAV-based remote sensing for the prediction of aboveground biomass and N fixation in legume-grass mixtures
(2020-07)
The world population is growing steadily and with it the demand for meat and animal protein. A major source of feed for livestock is grassland, which serves as high quality and protein rich forage. In addition to permanent grassland, temporary grassland is a valuable crop rotation element, especially in organic farming, since legumes in legume-grass mixtures can fix atmospheric nitrogen (NFix). To further increase the intensification in agriculture, reliable non-destructive measurement techniques are needed as an ...
Dissertation
Interactions of organic amendments, pea (Pisum sativum L.) growth, arbuscular mycorrhizal fungi and other soil microorganisms
(2017-07-25)
Microbial decomposition of organic substances in soil is a central process for maintaining nutrient cycling, and it can be affected by the presence of plants, especially by mycorrhizal plants, in different ways. Organic fertilizers maintain soil fertility and increase crop productivity. Less attention has been paid to C-rich organic fertilizers. On the other hand, legumes are the main source of N input in organic farming. However, field peas grown as a sole crop suffer many problems that make the yield low and ...
Dissertation
Impact of sward type, cutting date and conditioning temperature on mass and energy flows in the integrated generation of solid fuel and biogas from semi-natural grassland
(2011-01-21)
Energy production from biomass and the conservation of ecologically valuable grassland habitats are two important issues of agriculture today. The combination of a bioenergy production, which minimises environmental impacts and competition with food production for land with a conversion of semi-natural grasslands through new utilization alternatives for the biomass, led to the development of the IFBB process. Its basic principle is the separation of biomass into a liquid fraction (press fluid, PF) for the production ...