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Dissertation
Amount, composition and turnover of organic matter in topsoils and subsoils under mature beech forest
(2017-12-15)
Two-third of the terrestrial carbon (C) is stored in soils, and up to 63 % of the soil organic C (SOC) is stored in subsoils (i.e. below 30 cm soil depth). Forest soils account for nearly 70 % of the global SOC, demonstrating their great importance regarding the global carbon cycle. The higher average age of the OC stored in subsoil indicates that the subsoil OC is more stable against microbial decomposition. The capability of soil to stabilize OC is affected by substrate characteristics (e.g. size, distribution, ...
Dissertation
Effects of tillage intensity on soil C, N, and P pools with different stability
(2013-11-29)
Es ist bekannt, dass die Umsatzdynamik der organischen Substanz von der Bodenbearbeitungsintensität abhängt. Bis jetzt sind nur wenige Daten zum Einfluss der Bearbeitungsintensität und des Zwischenfruchtanbaus auf C-, N-, und P-Dynamik im Ober- (0-5 cm Tiefe) und Unterboden (5-25 cm Tiefe) von Lössböden verfügbar. Hauptziele dieser Arbeit waren die (i) Quantifizierung des Einflusses von verschiedenen langzeitig durchgeführten Bearbeitungssystemen auf labile, intermediäre, und passive C- und N-Pools; (ii) Quantifizierung ...
Dissertation
Effects of grassland renovation on carbon concentrations and aggregate distribution in temperate grassland soils
(2013-12-05)
The effects of continuous tillage on the distribution of soil organic matter (SOM) and aggregates have been well studied for arable soils. However, less is known about the effects of sporadic tillage on SOM and aggregate dynamics in grassland soils. The objectives of the present thesis were (I) to study the longer-term effects of sporadic tillage of grassland on organic carbon (Corg) stocks and the distribution of aggregates and SOM, (II) to investigate the combined effects of sporadic tillage and fertilization on ...
Dissertation
Effects of grassland management intensification on dynamics of soil organic carbon and nitrogen in temperate grassland soils
(2018-05-09)
In Germany, about one third of the agricultural area is managed as permanent grassland. The predominant use of permanent grassland in Germany is mostly the production of fodder for meat or milk production, achieved by grazing or mowing. In addition, an increased demand for biomass to produce renewable energy has influenced grassland management in the last decade. Until 2013, a continuous decrease in grassland due to grassland conversion was recorded (from 2003 to 2013, by a total of about 5 %). The reduction in ...
Dissertation
Effects of the application of biochar and organic fertilizers as well as temperature on soil carbon and aggregate dynamics
(2017-11-27)
Soil aggregate formation is an important process for long-term carbon storage in soils. While it has been shown that plant residues exert a positive influence on aggregate formation, the effects of organic fertilizers such as cattle slurry or manure as well as the effects of biochar application to soil are less clear. Furthermore, little is known about the role of increased soil temperatures in aggregate dynamics.
The main objectives of this thesis were to analyse the effects of (i) cattle slurry and manure, (ii) ...
Dissertation
Effect of environmental conditions on the N uptake route of soil microorganisms and adaption of a method to determine amino acid oxidase in soil
(2015-06-10)
Soil microorganisms have evolved two possible mechanisms for their uptake of organic N: the direct route and the mobilization-immobilization-turnover (MIT) route. In the direct route, simple organic molecules are taken up via various mechanisms directly into the cell. In the MIT route, the deamination occurs outside the cell and all N is mineralized to NH4+ before assimilation. A better understanding of the mechanisms controlling the different uptake routes of soil microorganisms under different environmental conditions ...
Dissertation
Das Arbeitshaus Breitenau
(Gesamthochschule Kassel; Verein für hessische Geschichte und Landeskunde e.V., 1992)
Aufsatz
Agri-environmental evaluation of traditional and alternative corn production systems in Chiapas, Mexico
(Kassel University Press, 2011)
This study evaluates the effects of environmental variables on traditional and alternative agroecosystems in three Ejidos (communal lands) in the Chiapas rainforest in Mexico. The tests occurred within two seasonal agricultural cycles. In spring-summer, experiments were performed with the traditional slash, fell and burn (S-F-B) system, no-burn systems and rotating systems with Mucuna deeringiana Bort., and in the autumn-winter agricultural cycle, three no-burn systems were compared to evaluate the effect of alternative ...
Aufsatz
Soil fertility and nutrient status of traditional Gayo coffee agroforestry systems in the Takengon region, Aceh Province, Indonesia
(Kassel University Press, 2011)
Little is known about the traditional coffee cultivation systems in Central Aceh, Indonesia, where coffee production is a major source of income for local Gayo people. Based on field observations and farmer interviews, 14 representative agroforestry coffee plantations of different age classes (60-70 years, 30-40 years, and 20 years) as well as seven adjacent grassland and native forest sites were selected for this study, and soil and coffee leaf samples collected for nutrient analysis. Significant differences in soil ...
Aufsatz
Domestic policy responses to the food price crisis: The case of Bolivia
(Kassel University Press, 2011)
In face of the global food crisis of 2007-2008, severe concerns arose about how developing countries would be affected by the extreme short-term fluctuations in international commodity prices. We examine the effects of the crisis on Bolivia, one of the poorest countries of the Americas. We focus on the effectiveness of the domestic policy interventions in preventing spillovers of the development of international food prices to domestic markets. Using a cointegration model, we study price interdependencies of wheat ...