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Dissertation
Produktion und Nutzung von mikrobiellen Residuen als labile Zwischenspeicher für Nährstoffe
(2006-06-28)
Mit dem Ziel, die Bildung und den Verbrauch von mikrobiellen Residuen zu ermitteln, wurden zwei Inkubationsversuche durchgeführt. Die Versuchsdauer betrug jeweils 67 Tage, wobei an den Tagen 5, 12, 33, 38, 45 und 67 Proben entnommen und auf Ct, Cmik, CO2 sowie die δ13C-Werte, Nt, Nmin und Ergosterol untersucht wurden. In Versuch 1 wurden als leicht umsetzbare Kohlenstoffquelle 3 mg C4-Kohlenstoff g-1Boden in Form von Rohrzucker bzw. Maiscellulose und als N-Ausgleich 200 µg NH4NO3-N g-1Boden hinzugegeben. Der verwendete ...
Dissertation
Combined use of spectral signatures and ultrasonic sward height for the assessment of biomass and quality parameters in heterogeneous pastures
(2017-06-21)
Precision management of grasslands requires accurate information on sward characteristics at a spatial and temporal scale. Multi-sensor data fusion provides data for site-specific grassland management. The present study aimed to demonstrate the potential of using a combination of ultrasonic and hyper-spectral sensor data fusion to predict forage quality (crude protein and acid detergent fiber) and biomass in heterogeneous pastures. The ability of a mobile sensing system equipped with both sensors to quantify within-field ...
Dissertation
Energetische Verwertung städtischen Laubs
(2017-11-28)
Das relativ saubere Parklaub und verschmutzte städtische Straßenlaub wurde durch das IFBB-Verfahren nach seiner energetischen Verwertbarkeit untersucht. Das Parklaub wurde durch das typische IFBB-Verfahren verarbeitet. Da das Straßenlaub durch Störstoffe (Sand, Kies, Plastik, Papier, Metallstücke) belastet war, bestand die Notwendigkeit es gründlich zu reinigen. Deswegen wurde der Vorgang der Konditionierung des IFBB-Verfahrens bei 40°C bei Straßenlaub durch den Reinigungsprozess bei 10-12°C ersetzt. Das Pressen in ...
Dissertation
Laboratory and field experiment evaluation of alternatives for maize in biogas production
(2017-09-28)
The objective of this thesis was to investigate possible alternatives to monocropped maize for the production of biogas.
The strategy of double-cropping for the production of biogas substrates is addressed by degradation experiments with maize as the standard crop and the two alternative crops sunflower and sorghum-sudangrass. Biological degradation experiments were made in biogas batch reactors for all three crops in each maturity stage. The remaining material was analysed for different chemical parameters to ...
Dissertation
Aufbereitete Aluminium-Salzschlacke als Rekultivierungsmaterial : Untersuchungen zum Stoff- und Wasserhalthalt eines Rekultivierungsmaterials im Labor und Freiland
(Universität Kassel, FB 11, Ökologische Agrarwissenschaften, 2002-09-23)
Dissertation
Effects of transformation processes in 'jubraka' agroforestry systems of the Nuba Mountains, Sudan, on nutrient fluxes
(2014-03-19)
Intensification processes in homegardens of the Nuba Mountains, Sudan, raise concerns about strongly positive carbon (C) and nutrient balances which are expected to lead to substantial element losses from these agroecosystems, in particular via soil gaseous emissions. Therefore, this thesis aimed at the quantification of C, nitrogen (N), phosphorus (P) and potassium (K) input and output fluxes with a special focus on soil gaseous losses, and the calculation of respective element balances. A further focus in this ...
Dissertation
Causes of legume rotation induced yield increases in cereals grown on West African soils
(2013-08-28)
This study was conducted to investigate soil biological and chemical factors that give rise to cereal yield enhancing effects of legume rotations on sandy, nutrient poor West African soils. The aim was not only to gain more information on the role of legume residues and microorganisms in the soil nutrient cycle. But the study aimed at evaluating if differences in substrate qualities (e.g. root residues) cause changes in the microbial community structure due to specific and highly complex microbe-root-soil interactions. ...
Dissertation
Agricultural practices and horizontal nutrient balances in urban gardens and the alternative use of urban agricultural land in Khartoum, Sudan
(2012-02-16)
The surge in the urban population evident in most developing countries is a worldwide phenomenon, and often the result of drought, conflicts, poverty and the lack of education opportunities. In parallel with the growth of the cities is the growing need for food which leads to the burgeoning expansion of urban and peri-urban agriculture (UPA). In this context, urban agriculture (UA) contributes significantly to supplying local markets with both vegetable and animal produce. As an income generating activity, UA also ...