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Dissertation
Effects of fertilizer type and rate on partitioning of soil organic matter into pools of different stability
(2010-05-26)
Type and rate of fertilizers influence the level of soil organic carbon (Corg) and total nitrogen (Nt) markedly, but the effect on C and N partitioning into different pools is open to question. The objectives of the present work were to:
(i) quantify the impact of fertilizer type and rate on labile, intermediate and passive C and N pools by using a combination of biological, chemical and mathematical methods;
(ii) explain previously reported differences in the soil organic matter (SOM) levels between soils receiving ...
Dissertation
Effects of tillage on processes of organic matter sequestration
(2010-06-28)
To increase the organic matter (OM) content in the soil is one main goal in arable soil management. The adoption of tillage systems with reduced tillage depth and/or frequency (reduced tillage) or of no-tillage was found to increase the concentration of soil OM compared to conventional tillage (CT; ploughing to 20-30 cm). However, the underlying processes are not yet clear and are discussed contradictorily. So far, few investigations were conducted on tillage systems with a shallow tillage depth (minimum tillage = ...
Dissertation
Horizontal nutrient fluxes and production efficiencies in urban and peri-urban crop and livestock husbandry of Niamey, Niger
(2009-11-17)
Urban and peri-urban agriculture (UPA) increasingly supplies food and non-food values to the rapidly growing West African cities. However, little is known about the resource use efficiencies in West African small-scale UPA crop and livestock production systems, and about the benefits that urban producers and retailers obtain from the cultivation and sale of UPA products. To contribute to filling this gap of knowledge, the studies comprising this doctoral thesis determined nutrient use efficiencies in representative ...
Dissertation
Combining crop growth models with the Precision Agriculture concept of yield gap analysis to evaluate yield limiting and reducing factors
(2022)
The agricultural sector is considered as one of the main elements of a “functional” society and its welfare for providing means to fulfil the most basic human need for food. In the past, an improved overall welfare of developed countries was directly related to early investment in conventional farming machinery parallel to the industrial development. With the expected future population increase and climate change, farm yield gaps are expected to increase and become more volatile. The awareness of negative externalities ...
Dissertation
Effects of different tillage treatments on labile soil organic matter pools and stabilization processes
(2013-06-26)
An improved understanding of soil organic carbon (Corg) dynamics in interaction with the mechanisms of soil structure formation is important in terms of sustainable agriculture and reduction of environmental costs of agricultural ecosystems. However, information on physical and chemical processes influencing formation and stabilization of water stable aggregates in association with Corg sequestration is scarce. Long term soil experiments are important in evaluating open questions about management induced effects on ...
Dissertation
Kooperationspotenziale 'Grüner Werkstätten' und Beschäftigungspotenziale landwirtschaftlicher Betriebe sowie des branchennahen Handwerks für Menschen mit Behinderung
(2013-07-30)
In den bundesweit rund 670 anerkannten Werkstätten für behinderte Menschen (WfbM) arbeiten aktuell über 290 000 Menschen mit Behinderung. Rund ein Viertel dieser Einrichtungen bieten auch landwirtschaftliche oder gartenbauliche Arbeitsplätze (`Grüne WfbM´). Die UN-Behindertenrechtskonvention fordert u. a. eine inklusive Teilhabe der Menschen mit Behinderung am Arbeitsleben in Form von Zugangsmöglichkeiten zu sozialversicherungspflichtiger Beschäftigung auf dem allgemeinen Arbeitsmarkt.
Gleichzeitig können ...
Dissertation
The European organic food market - how to increase its transparency?
(2010-12-06)
Der Europäische Markt für ökologische Lebensmittel ist seit den 1990er Jahren stark gewachsen. Begünstigt wurde dies durch die Einführung der EU-Richtlinie 2092/91 zur Zertifizierung ökologischer Produkte und durch die Zahlung von Subventionen an umstellungswillige Landwirte. Diese Maßnahmen führten am Ende der 1990er Jahre für einige ökologische Produkte zu einem Überangebot auf europäischer Ebene. Die Verbrauchernachfrage stieg nicht in gleichem Maße wie das Angebot, und die Notwendigkeit für eine Verbesserung des ...
Dissertation
Streu- und Feuchtwiesen im Kempter Wald
(2007-08-22)
Der Kempter Wald ist aufgrund seiner großflächigen prioritären Lebensräume - den Hoch- und Übergangsmooren - aber auch den landesweit selten gewordenen und durch Nutzungsaufgabe bedrohten Streuwiesen und Flachmoorgesellschaften ein Landschaftsraum von herausragender naturschutzfachlicher Bedeutung. Ausgehend von der nach wie vor aktuellen Debatte um die Schutzgebietsausweisung im Kempter Wald wurde auf dem Gebiet der Marktgemeinde Unterthingau und der Gemeinde Kraftisried die vorhandene Grünlandvegetation auf ...
Dissertation
Designing Breeding Programs For Improving Milk Yield Performance Of Indigenous Genous Dairy Cattle In Sudan
(2022)
The overall aim of the present study was to design appropriate breeding programs for the sustainable improvement of Butana cattle in Sudan. Four studies were conducted, beginning with a comprehensive review of literature on indigenous dairy cattle breeding strategies in sub-Saharan Africa with a focus on the factors that contribute to their success or failure. It showed that crossbreeding of indigenous breeds with exotic breeds has been widely used for genetic improvement, but it largely failed under low-input ...
Dissertation
Land tenure in a changing climate
(2023)
Climate change and extreme weather have far-reaching impacts on agriculture. They do not only affect agricultural production, but also fundamental assets that shape agricultural livelihoods. In this dissertation, I study the relation of weather and climate with agricultural land tenure in low- and middle-income countries. Secure access to land is of vital importance for farmers, but insecure tenure is a reality for millions of farmers around the globe. They are unsure whether they will be able to continue farming ...