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Now showing items 11-20 of 27
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
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
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
Conservation agriculture in organic farming: Impacts on weeds and plant-parasitic nematodes during the transition
(2017-10-12)
Der Bodenschutz ist eine der wichtigsten Anforderungen an die Landwirtschaft im 21. Jahrhundert. Daher sind nicht-wendende Bodenbearbeitungssysteme, basierend auf dem Anbau von Untersaaten und Zwischenfrüchten, verstärkt in den Fokus der europäischen Agrarwirtschaft geraten. Allerdings können diese neuartigen Systeme das Spektrum und die Abundanz gewisser Krankheiten, Schädlinge und Unkräuter grundlegend verändern. Ein Beispiel ist die Zunahme von Unkräutern und ihren Samenbanken während der Übergangsphase von ...
Dissertation
Studies on the diversity of the main necrotrophic pathogens on wheat and barley Pyrenophora tritici-repentis and Cochliobolus sativus
(2017-10-30)
Leaf blights such as tan spot of wheat (Pyrenophora tritici-repentis) and spot blotch of barley (Cochliobolus sativus) are among the main constraints in achieving high and stable yields and are the main concerns among the several intrinsic drawbacks of narrow cropping sequencesas both are residue borne. The development of useful and durable resistance against prevalent races requires detailed information on the virulence diversity of the pathogen and the type of resistances available in the host. Thus, the focus of ...
Dissertation
Sensor psychrometric approaches to mitigating aflatoxins in maize dried on farms in Kenya
(2017-01-23)
Kenia liegt in den Äquatorialtropen von Ostafrika und ist als ein weltweiter Hot-Spot für Aflatoxinbelastung insbesondere bei Mais bekannt. Diese toxischen und karzinogenen Verbindungen sind Stoffwechselprodukte von Pilzen und so insbesondere von der Wasseraktivität abhängig. Diese beeinflusst sowohl die Trocknung als auch die Lagerfähigkeit von Nahrungsmitteln und ist somit ein wichtiger Faktor bei der Entwicklung von energieeffizienten und qualitätsorientierten Verarbeitungsprozessen. Die vorliegende Arbeit hat ...
Dissertation
Akustische Echtzeit-Erkennung des Messerzustandes in Feldhäckslern
(2017-03-23)
In der vorliegenden Dissertation wurde die Machbarkeit einer akustischen Messerzustandserkennung am selbstfahrenden Feldhäcksler untersucht. Gegenstand waren die Charakteri- sierung des schneidkraftinduzierten Körperschalls, Untersuchung des Zusammenhangs von Körperschall und Schleifintensität bzw. Ernteleistung, Erarbeitung von Auslegungskriterien für die Sensorik (Position, Messrichtung, Frequenzbereich) und für die Analysesoftware (Zeit- und Frequenzbereichsverfahren).
Der Schneidprozess wurde in seiner prinzipiellen ...