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Dissertation
Effects of plant diversity on bioenergy parameters in grassland biomass
(2013-01-28)
Extensive grassland biomass for bioenergy production has long been subject of scientific research. The possibility of combining nature conservation goals with a profitable management while reducing competition with food production has created a strong interest in this topic. However, the botanical composition will play a key role for solid fuel quality of grassland biomass and will have effects on the combustion process by potentially causing corrosion, emission and slagging. On the other hand, botanical composition ...
Dissertation
Alley cropping of willows and grassland for bioenergy provision: productivity, tree-crop interactions and energy balance
(2015-08-12)
The demand for biomass for bioenergy has increased rapidly in industrialized countries in the recent years. Biogenic energy carriers are known to reduce CO2 emissions. However, the resource-inefficient production of biomass often caused negative impacts on the environment, e.g. biodiversity losses, nitrate leaching, and erosion. The detrimental effects evolved mainly from annual crops. Therefore, the aim of modern bioenergy cropping systems is to combine yield stability and environmental benefits by the establishment ...
Dissertation
Urban Grass and Grass-Leaf Litter Mixtures as Source for Bioenergy Recovery
(2016-03-02)
Städtische Biomassen der Grünflächen bilden eine potentielle, bisher weitgehend ungenutzte Ressource für Bioenergie. Kommunen pflegen die Grünflächen, lassen das Material aber verrotten oder führen es Deponien oder Müllverbrennungsanlagen zu. Diese Praxis ist kostenintensiv ohne für die Verwaltungen finanziellen Ausgleich bereitzustellen. Stattdessen könnte das Material energetisch verwertet werden. Zwei mögliche Techniken, um Bioenergie zu gewinnen, wurden mit krautigem Material des städtischen Straßenbegleitgrüns ...
Dissertation
Nitrogen and carbon dynamics in grassland soils and plants after application of digestate
(2015-05-20)
A better understanding of effects after digestate application on plant community, soil microbial community as well as nutrient and carbon dynamics is crucial for a sustainable grassland management and the prevention of species and functional diversity loss. The specific research objectives of the thesis were:
(i) to investigate effects after digestate application on grass species and soil microbial community, especially focussing on nitrogen dynamic in the plant-soil system and to examine the suitability of the ...
Dissertation
Integrated soil fertility management in eastern and western Africa: The role of knowledge and innovation systems, its adoption and impact
(2017-01-31)
The rise in population growth, as well as nutrient mining, has contributed to low agricultural productivity in Sub-Saharan Africa (SSA). A plethora of technologies to boost agricultural production have been developed but the dissemination of these agricultural innovations and subsequent uptake by smallholder farmers has remained a challenge. Scientists and philanthropists have adopted the Integrated Soil Fertility Management (ISFM) paradigm as a means to promote sustainable intensification of African farming systems. ...
Dissertation
Nitrogen use efficiency and optimization of nitrogen fertilizer application for stable yields and high quality of cereals grown in conservation agriculture
(2017-01-23)
In most agroecosystems, nitrogen (N) is the most important nutrient limiting plant growth. One management strategy that affects N cycling and N use efficiency (NUE) is conservation agriculture (CA), an agricultural system based on a combination of minimum tillage, crop residue retention and crop rotation. Available results on the optimization of NUE in CA are inconsistent and studies that cover all three components of CA are scarce. Presently, CA is promoted in the Yaqui Valley in Northern Mexico, the country´s major ...
Dissertation
Water use efficiency and management of agro-pastoral landuse systems in the Mongolian-Chinese Altay
(2017-02-08)
The use of organic fertilizers is an important approach to maintain soil fertility of irrigated agricultural land under the semi-arid climate conditions of Oman. However, gaseous emissions of carbon and nutrients from soil and organic fertilizers are a major challenge. Activated charcoal and tannins have the potential to reduce gaseous losses of carbon and nitrogen. Therefore, gaseous emissions of carbon dioxide (CO2), ammonia (NH3) and nitrous oxide (N2O) were measured by a photo-acoustic infrared multi-gas monitor. ...
Dissertation
Effects of activated charcoal and quebracho tannins on the turnover of goat manure in irrigated organic agriculture of the subtropics
(2015-04-15)
Agriculture in semi-arid and arid regions is constantly gaining importance for the security of the nutrition of humankind because of the rapid population growth. At the same time, especially these regions are more and more endangered by soil degradation, limited resources and extreme climatic conditions. One way to retain soil fertility under these conditions in the long run is to increase the soil organic matter. Thus, a two-year field experiment was conducted to test the efficiency of activated charcoal and quebracho ...
Dissertation
Effects of phosphorus and water stress on shoot and root growth and on mycorrhization of different pearl millet (Pennisetum glaucum (L.) R. Br.) varieties from West Africa
(2015-03-13)
This research work aimed at investigating the physiological mechanisms of tolerance of pearl millet to low soil Phosphorus availability and drought under the Sahelian conditions.
Dissertation
Effects of irrigation water quality on soil properties and crops in urban gardens of Ouagadougou, Burkina Faso
(2018-02-15)
Urban food production is an important supplier of fresh produce in the rapidly growing West African cities. In year-round vegetable production of the semi-arid tropics, low quality water is often use for irrigation. This results in health risks for producers and consumers, and causes environmental pollution, followed by soil contamination and crop yield reduction. In the presented PhD thesis quality and effects of irrigation water in urban vegetable gardens of Ouagadougou, Burkina Faso, were examined. The aim of these ...