Die Festschrift zeichnet die Entwicklung der Agrar- und Ernährungswissenschaftlichen Fakultät der... more Die Festschrift zeichnet die Entwicklung der Agrar- und Ernährungswissenschaftlichen Fakultät der Christian-Albrechts-Universität zu Kiel von ihrer Vorgeschichte bis zur Gegenwart nach. Gezeigt wird der Wandel der Instituts- und Forschungsstruktur ebenso wie der Weg vom einstigen Landwirtschafts- zum heutigen Bachelor- und Masterstudium der Agrar- und Ernährungswissenschaften. Von der Phase der Ernährungssicherung nach dem Zweiten Weltkrieg bis zu den aktuellen vernetzten Forschungsgebieten haben sich Agrarökonomie, Ernährungs-, Nutzpflanzen-, Nutztier- und Umweltwissenschaften in den vergangenen 75 Jahren stark verändert. Damals wie heute sind sie gleichwohl gesellschaftlich hochrelevante Leuchttürme der Forschung im hohen Norden.
Abstract Effective stress is an important strength indicator for understanding and fundamentally ... more Abstract Effective stress is an important strength indicator for understanding and fundamentally predicting soil behaviour due to mechanical disturbance. This study investigated the influence of `soil properties on effective stress in relation to matric potential, and soil sampling direction (vertical/horizontal). Undisturbed soil samples representing 3 different locations were collected at 4 depths and in 2 sampling directions, to determine which soil properties mostly affect the effective stress in response to the magnitude of the stress applied. The soil properties included texture, organic carbon content, dry bulk density, void ratio, pre-compression stress and prevailing matric potential. The results showed that both the effective stress and the concomitant changes in pore water pressure largely depend on the prevailing matric potential in the soil. In addition, changes in soil structure caused by subsurface soil compaction as a result of tillage, organic carbon and clay content influenced the magnitude of the effective stress and pore water pressure in soils during loading. The porewater pressure measured under static loading is sampling direction dependent due to differences in hydraulic conductivity and pore continuity. Porewater pressure increases (become less negative) with increases in the fraction of fine pores in the soil while it may either remain constant or decrease, when the medium and coarse pore fractions in the soil increases. This implies that the smaller the pore connectivity and continuity, the less negative the changes in pore water pressure become. Also, the higher the pre-compression stress (sometimes due to higher organic carbon content), the more consistent the applied stress induced an increase in the calculated effective stress.
For permanent sealin of the base liner of waste deposits, the mineral material should possess pro... more For permanent sealin of the base liner of waste deposits, the mineral material should possess properties as a high incompressibility, very low hydraulic conductivities, dominance of fine pores, a low capacity of swelling and shrinkage and a high physicochemical buffering capacity (Fig. 1).
Water and solute transports in the vadose zone depend on the distribution, size, shape and config... more Water and solute transports in the vadose zone depend on the distribution, size, shape and configuration of the pores. They affect the soil hydraulic properties and, consequently, the directly related processes such as water storage, infiltration, groundwater recharge, and also erosion and runoff. Soils amended with biochar are prompt to improve their physical and hydraulic properties. Biochar addition alters not only porosity, the water retention pattern and the derived pore distribution, but also the hydraulic conductivity under saturated and unsaturated conditions. In our work, two different doses (2.5 and 5% dry wt.) were added to two textured soils (sand and sandy loam). The unsaturated hydraulic conductivity and saturated hydraulic conductivity were measured under laboratory conditions. The obtained results show the positive effect of biochar on the hydraulic functions. For the sandy soil, the higher the dose of biochar, the more constant and relatively higher is the hydraulic...
The soil shrinkage behavior of mineral substrates needs to be considered for engineering long-ter... more The soil shrinkage behavior of mineral substrates needs to be considered for engineering long-term durable mineral liners of landfill capping systems. For this purpose, a novel three-dimensional laser scanning device was coupled with (a) a mathematical-empirical model and (b) in-situ tensiometer measurements as a combined approach to simultaneously determine the shrinkage behavior of a boulder marl, installed as top and bottom liner material at the Rastorf landfill (Northern Germany). The shrinkage behavior, intensity, and geometry were determined during a drying experiment with undisturbed soil cores (100 cm3) from two soil pits; the actual in-situ shrinkage was also determined in 0.2, 0.5, 0.8, and 1.0 m depth by pressure transducer tensiometer measurements during a four-year period. The volume shrinkage index was used to describe the pore size dependent shrinkage tendency and it was classified as low (4.9%) for the bottom liner. The in-situ matric potentials in the bottom liner r...
Soil management alters physical, chemical and biological soil properties. Stress application affe... more Soil management alters physical, chemical and biological soil properties. Stress application affects microbiological activity and habitats for microorganisms in the root zone and causes soil degradation. We hypothesized that stress application results in altered greenhouse gas emissions if soil strength is exceeded. In the experiments, soil management dependent greenhouse gas emissions of intact soil cores (no, reduced, conventional tillages) were determined using two experimental setups; CO2 emissions were determined with: a dynamic measurement system, and a static chamber method before and after a vertical soil stress had been applied. For the latter CH4 and N2O emissions were analyzed additionally. Stress dependent effects can be summed as follows: In the elastic deformation range microbiological activity increased in conventional tillage soil and decreased in reduced tillage and no tillage. Beyond the precompression stress a release of formerly protected soil organic carbon and ...
Die Stellung der Böden im Stoffkreislauf der Lithosphäre (Abb. 2.1-1) zeigt, dass an der Gesteins... more Die Stellung der Böden im Stoffkreislauf der Lithosphäre (Abb. 2.1-1) zeigt, dass an der Gesteinsbildung, der Lithogenese, eine große Zahl von Prozessen in Form eines Kreislaufs beteiligt sind. Beim Abkühlen glutflüssigen Magmas entstehen am Beginn der Lithogenese Gesteine durch Kristallisation aus der Schmelze. Sie unterliegen weiteren vielfältigen Veränderungen durch die Prozesse Verwitterung, Abtragung, Transport, Ablagerung, Diagenese, Metamorphose und Anatexis, die
Die Festschrift zeichnet die Entwicklung der Agrar- und Ernährungswissenschaftlichen Fakultät der... more Die Festschrift zeichnet die Entwicklung der Agrar- und Ernährungswissenschaftlichen Fakultät der Christian-Albrechts-Universität zu Kiel von ihrer Vorgeschichte bis zur Gegenwart nach. Gezeigt wird der Wandel der Instituts- und Forschungsstruktur ebenso wie der Weg vom einstigen Landwirtschafts- zum heutigen Bachelor- und Masterstudium der Agrar- und Ernährungswissenschaften. Von der Phase der Ernährungssicherung nach dem Zweiten Weltkrieg bis zu den aktuellen vernetzten Forschungsgebieten haben sich Agrarökonomie, Ernährungs-, Nutzpflanzen-, Nutztier- und Umweltwissenschaften in den vergangenen 75 Jahren stark verändert. Damals wie heute sind sie gleichwohl gesellschaftlich hochrelevante Leuchttürme der Forschung im hohen Norden.
Abstract Effective stress is an important strength indicator for understanding and fundamentally ... more Abstract Effective stress is an important strength indicator for understanding and fundamentally predicting soil behaviour due to mechanical disturbance. This study investigated the influence of `soil properties on effective stress in relation to matric potential, and soil sampling direction (vertical/horizontal). Undisturbed soil samples representing 3 different locations were collected at 4 depths and in 2 sampling directions, to determine which soil properties mostly affect the effective stress in response to the magnitude of the stress applied. The soil properties included texture, organic carbon content, dry bulk density, void ratio, pre-compression stress and prevailing matric potential. The results showed that both the effective stress and the concomitant changes in pore water pressure largely depend on the prevailing matric potential in the soil. In addition, changes in soil structure caused by subsurface soil compaction as a result of tillage, organic carbon and clay content influenced the magnitude of the effective stress and pore water pressure in soils during loading. The porewater pressure measured under static loading is sampling direction dependent due to differences in hydraulic conductivity and pore continuity. Porewater pressure increases (become less negative) with increases in the fraction of fine pores in the soil while it may either remain constant or decrease, when the medium and coarse pore fractions in the soil increases. This implies that the smaller the pore connectivity and continuity, the less negative the changes in pore water pressure become. Also, the higher the pre-compression stress (sometimes due to higher organic carbon content), the more consistent the applied stress induced an increase in the calculated effective stress.
For permanent sealin of the base liner of waste deposits, the mineral material should possess pro... more For permanent sealin of the base liner of waste deposits, the mineral material should possess properties as a high incompressibility, very low hydraulic conductivities, dominance of fine pores, a low capacity of swelling and shrinkage and a high physicochemical buffering capacity (Fig. 1).
Water and solute transports in the vadose zone depend on the distribution, size, shape and config... more Water and solute transports in the vadose zone depend on the distribution, size, shape and configuration of the pores. They affect the soil hydraulic properties and, consequently, the directly related processes such as water storage, infiltration, groundwater recharge, and also erosion and runoff. Soils amended with biochar are prompt to improve their physical and hydraulic properties. Biochar addition alters not only porosity, the water retention pattern and the derived pore distribution, but also the hydraulic conductivity under saturated and unsaturated conditions. In our work, two different doses (2.5 and 5% dry wt.) were added to two textured soils (sand and sandy loam). The unsaturated hydraulic conductivity and saturated hydraulic conductivity were measured under laboratory conditions. The obtained results show the positive effect of biochar on the hydraulic functions. For the sandy soil, the higher the dose of biochar, the more constant and relatively higher is the hydraulic...
The soil shrinkage behavior of mineral substrates needs to be considered for engineering long-ter... more The soil shrinkage behavior of mineral substrates needs to be considered for engineering long-term durable mineral liners of landfill capping systems. For this purpose, a novel three-dimensional laser scanning device was coupled with (a) a mathematical-empirical model and (b) in-situ tensiometer measurements as a combined approach to simultaneously determine the shrinkage behavior of a boulder marl, installed as top and bottom liner material at the Rastorf landfill (Northern Germany). The shrinkage behavior, intensity, and geometry were determined during a drying experiment with undisturbed soil cores (100 cm3) from two soil pits; the actual in-situ shrinkage was also determined in 0.2, 0.5, 0.8, and 1.0 m depth by pressure transducer tensiometer measurements during a four-year period. The volume shrinkage index was used to describe the pore size dependent shrinkage tendency and it was classified as low (4.9%) for the bottom liner. The in-situ matric potentials in the bottom liner r...
Soil management alters physical, chemical and biological soil properties. Stress application affe... more Soil management alters physical, chemical and biological soil properties. Stress application affects microbiological activity and habitats for microorganisms in the root zone and causes soil degradation. We hypothesized that stress application results in altered greenhouse gas emissions if soil strength is exceeded. In the experiments, soil management dependent greenhouse gas emissions of intact soil cores (no, reduced, conventional tillages) were determined using two experimental setups; CO2 emissions were determined with: a dynamic measurement system, and a static chamber method before and after a vertical soil stress had been applied. For the latter CH4 and N2O emissions were analyzed additionally. Stress dependent effects can be summed as follows: In the elastic deformation range microbiological activity increased in conventional tillage soil and decreased in reduced tillage and no tillage. Beyond the precompression stress a release of formerly protected soil organic carbon and ...
Die Stellung der Böden im Stoffkreislauf der Lithosphäre (Abb. 2.1-1) zeigt, dass an der Gesteins... more Die Stellung der Böden im Stoffkreislauf der Lithosphäre (Abb. 2.1-1) zeigt, dass an der Gesteinsbildung, der Lithogenese, eine große Zahl von Prozessen in Form eines Kreislaufs beteiligt sind. Beim Abkühlen glutflüssigen Magmas entstehen am Beginn der Lithogenese Gesteine durch Kristallisation aus der Schmelze. Sie unterliegen weiteren vielfältigen Veränderungen durch die Prozesse Verwitterung, Abtragung, Transport, Ablagerung, Diagenese, Metamorphose und Anatexis, die
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