Das Projekt "B 2.3: Transport of agrochemicals in a watershed in Northern Thailand - Phase 3" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Bodenkunde und Standortslehre, Fachgebiet Biogeophysik durchgeführt. Land use changes of the last decades in the mountainous regions of Northern Thailand have been accompanied by an increased input of agrochemicals, which might be transferred to rivers by surface and/or subsurface flow. Where the river water is used for household consumption, irrigation and other purposes, agrochemical losses pose a serious risk to the environment and food safety. In the first and the second phase, subproject B2 collected data on and gained knowledge of the vertical and lateral transport processes that govern the environmental fate of selected agrochemicals at the plot and the hillslope scale (Ciglasch et al., 2005; Kahl et al., 2006). In the third phase, B2.3 will turn from the hillslope to the watershed scale. For simulation of water flow and pesticide transport the SWAT model (Neitsch et al., 2002b) will be adapted and used. The study area will be the Mae Sa watershed (138 km2), which includes the Mae Sa Noi subcatchment where B2 carried out detailed investigations during the last two phases. The specific focus of the subproject will be the parameterization and calibration of the SWAT model and its integration into the model network of the SFB. The SFB database has been established and can be used for model parameterization. In addition, high-quality geo-data are available from the Geoinformatic and Space Technology Development Agency (GISTDA) in Chiang Mai. For model calibration, discharge measurements are available for the Mae Sa Noi subcatchment (12 km2) and for the neighboring Mae Nai subcatchment (18 km2). To collect data on the Mae Sa watershed discharge, at the very beginning of the third phase gauging stations will be established in a midstream position and at the outlet of the watershed. Pesticide fluxes will be measured at each gauging station as well as in the Mae Sa Noi subcatchment, where B2.2 has operated two flumes equipped with automatic discharge-proportional water samplers since 2004. Rainfall distribution and intensity will be monitored with a net of automatic rain gauges. Hydrograph separation will be performed using soil and river temperatures (Kobayashi et al., 1999). Within the watershed temperature loggers will be installed at different soil depths to measure the temperature of the different discharge components. Already at the beginning of the second year of the third phase we will start to couple the SWAT model with land use and farm household models of the SFB and to use the model to assess the effect of land use and land management changes on the loss of pesticides to surface waters.
Das Projekt "Element cycles in mountain regions under various land use" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Geowissenschaften, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Agrarökosystemforschung durchgeführt. Research question: What is the role of agricultural land use in changes of nutrient cycles and losses dependingon surface slope and climate? Approach: Annual balance of main nutrients for 3-4 main agricultural farms based on fertilizer input, partitioning of nutrients in above and below ground plant parts, output with harvest, losses with DOM and erosion (in collaboration with other TP). The balances will be done depending on agricultural practices in Eger and Haean Catchment and will be compared with adjacent grassland and forest. Obtained element cycles will be upscaled from farm area to the level of both catchments basins depending on specific land use, surface slope and climate. Research question: Can we reconstruct previous erosion and nutrient losses and separate them under forest and under agricultural use? Approach: Undisturbed sediment cores (7 for Eger and 7 for Haean) will be taken from the lakes and soils of landscapes subordinated to agricultural fields. Three radiocarbon data of wood particles at increasing depth for each sediment core will be used as references. The age of the bottom sediment layer should be less than 1000 years. The total content of C, N, P, K, Mg, Ca, Si will be analyzed in individual laminae or sediment layers. Conclusions will be drawn based on the thickness of the laminae, their elements content and the ratio between nutrients and Si. The conclusions will be proven by 13C (vegetation change) and 15N (N input by fertilizers) of individual laminae. Research question: What are the best management practices for sloping uplands? Approach: Measured element cycles and losses under various agriculture practice will be analysed and practices with the least nutrient losses and erosion will be selected. The best management practices for landscapes with different slopes will be elaborated.
Das Projekt "The role of turgor in rain-cracking of sweet cherry fruit" wird vom Umweltbundesamt gefördert und von Leibniz Universität Hannover, Institut für Biologische Produktionssysteme, Fachgebiet Obstbau durchgeführt. Rain-cracking limits the production of many soft and fleshy fruit including sweet cherries world wide. Cracking is thought to result from increased water uptake through surface and pedicel. Water uptake increases fruit volume, and hence, turgor of cells (Pcell) and the pressure inside the fruit (Pfruit) and subjects the skin to tangential stress and hence, strain. When the strain exceeds the limits of extensibility the fruit cracks. This hypothesis is referred to as the Pfruit driven strain cracking. Based on this hypothesis cracking is related to two independent groups of factors: (1) water transport characteristics and (2) the intrinsic cracking susceptibility of the fruit defined as the amount of cracking per unit water uptake. The intrinsic cracking susceptibility thus reflects the mechanical constitution of the fruit. Most studies focussed on water transport through the fruit surface (factors 1), but only little information is available on the mechanical constitution (i.e., Pfruit and Pcell, tensile properties such as fracture strain, fracture pressure and modulus of elasticity of the exocarp; factors 2). The few published estimates of Pfruit in sweet cherry are all obtained indirectly (calculated from fruit water potential and osmotic potentials of juice extracts) and unrealistically high. They exceed those measured by pressure probe techniques in mature grape berry by several orders of magnitude. The objective of the proposed project is to test the hypothesis of the Pfruit driven strain cracking. Initially we will focus on establishing systems of widely differing intrinsic cracking susceptibility by varying species (sweet and sour cherry, Ribes and Vaccinium berries, plum, tomato), genotype (within sweet cherry), stage of development and temperature. These systems will then be used for testing the hypothesis of Pfruit driven strain cracking. We will quantify Pfruit und Pcell by pressure probe techniques and compression tests and the mechanical properties of the exocarp using biaxial tensile tests. When the presence of high Pfruit and Pcell is confirmed by direct measurements, subsequent studies will focus on the mode of failure of the exocarp (fracture along vs. across cell walls) and the relationship between failure thresholds and morphometric characteristics of the exocarp. However, when Pfruit und Pcell are low, the hypothesis of Pfruit driven strain cracking must be rejected and the mechanistic basis for low pressures (presence of apoplastic solutes) clarified on a temporal (in the course of development) and a spatial scale (exocarp vs. mesocarp). We focus on sweet cherry, because detailed information on this species and experience in extending the short harvest period is available. Where appropriate, other cracking susceptible species (sour cherry, plum, Vaccinium, Ribes, tomato) will be included to further extend the experimental period and to maximize the range in intrinsic cracking susceptibility.
Das Projekt "Plant-soil interactions in changing rice cropping systems and their influence on C and N dynamics" wird vom Umweltbundesamt gefördert und von Universität Bonn, Institut für Nutzpflanzenwissenschaften und Ressourcenschutz - Pflanzenernährung (Prof. Werner) durchgeführt. Plant-soil interactions drive the input, cycling and losses of C and N in soil. This subproject aims at elucidating the input and fate of C in the soil-plant systems and its effect of N retention in soil under different paddy management (continuous vs. alternating with maize cropping). In particular we will investigate (i) how much of the assimilate C is released by the plants into the rhizosphere soil, and how this rhizodeposition is affected by N supply, soil density and crop variety during plant development, (ii) how the exudation of C and N responds to land use change, (iii) how C released into the rhizosphere affects the turnover of soil C and utilization of fertilizer N, and (iv) to what degree leaching contributes to the loss of C and N from the rooted surface soil. To answer these questions, we will combine the use of isotopic 13C and 15N labeling in laboratory and field experiments with a sophisticated characterization of root exudates, root border cells, and compound-specific isotope tracing in the residues of bacteria and fungi in rhizosphere, bulk soil as well as within different dissolved organic and inorganic carbon species in soil leachates. In this way and in collaboration with SP 2, 5, 6, and 7 of this research unit, our project links the cycling of C and N in paddy soils to one of its most prominent drivers, the release of organic compounds by roots.
Das Projekt "Sub project:The effect of iron(III)-sulfide interactions on electron transfer processes in anoxic aquifers" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Geowissenschaften, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Hydrologie durchgeführt. Strong evidence exists that the oxidation of H2S by ferric (oxyhydr)oxides occurs also in ground water systems and may exert a major role for the sulphur and iron cycle and in particular for the electron and carbon flow in aquifers. To date, no systematic study has been performed that allows to quantitatively assess its significance in such systems. This project aims to fill this gap of knowledge. The extent of the reaction depends on mineral reactivity, which we hypothesize can be expressed in terms of a generalized kinetic model for the full pH range of environmental relvance. This model accounts for the adsorption of H2S at lower pH values and of HS- at circumneutral pH to the neutral ferric (oxyhydr)oxide surface to form the reactive species FeSH. Variations in reactivity may be caused by intrinsic factors such as surface acidity of the iron mineral and solution composition, such as ionic strength and competition with other ions. The overall goals of this project therefore are to demonstrate the validity of this approach in order to quantify the kinetics for abiotic anaerobic H2S oxidation by ferric (oxyhydr)oxides, and to elucidate the role of this process as a precursor reaction for further microbial transformation of sulphur species in the aquifer.
Das Projekt "EWA Egypt - Möglichkeiten zur Verbesserung der Wasserverfügbarkeit in Ägypten" wird vom Umweltbundesamt gefördert und von Deutsches Zentrum für Luft- und Raumfahrt e.V. - Deutsches Fernerkundungsdatenzentrum durchgeführt. Das übergeordnete Ziel des Vorhabens ist es, zwei verschiedene Möglichkeiten für die Verbesserung der Wasserverfügbarkeit in Ägypten auszuweisen. Die vorgeschlagene Forschung konzentriert sich auf die Verfügbarkeit von Wasser in Ägypten. Dabei werden zwei Aspekte analysiert: a) wie können Änderungen der Landbedeckung lokale Niederschläge auslösen und b) Möglichkeiten zur Verdunstungs-Abschätzung über dem Nasser See. Die Methodik basiert auf modernsten Computer-Simulationen, gekoppelt mit einer Analyse von historischen Satellitenbildern und Wetterdaten. EWA Egypt ist in den Bereichen 'Klimawandel' und 'Wasser' vom BMBF und STDF angesiedelt. Es passt zu den Themen 'securing and sustaining water und 'combating drought and desertification des 'Consolidated Plan of Action of the African Union (CPA) und kann als Teil der EU-Afrika-Strategie zur Bekämpfung der Wüstenbildung durch eine nachhaltige Flächennutzung gesehen werden. Mit Hilfe von Satellitendaten-Analysen soll das DLR vorhandene Effekte von Wärmeinsel-induzieren Niederschlägen entdecken. Weiter stellt das DLR die 'surface boundary conditions für CWRF und berechnet Verdunstungskarten des Nasser Sees. Die Universität Kairo wird das CWRF Modell aufsetzen und betreiben, um mögliche Szenarien von Wärmeinsel-induzieren Niederschlägen zu simulieren und um in der Lage zu sein, die Verdunstung über dem Nasser See vorherzusagen.
Das Projekt "Storage of hydrogen in hydrides" wird vom Umweltbundesamt gefördert und von Weierstraß-Institut für Angewandte Analysis und Stochastik durchgeführt. Hydrogen is the ideal synthetic fuel to convert chemical energy into electrical energy or into motive power because it is light weight, highly abundant and its oxidation product is vapor of water. Thus its usage helps to reduce the greenhouse gases and it conserves fossile resources. There is even a clean way to produce hydrogen by electrolysis of water by means of photo voltaics (SvW06, VSM05, PMM05). There are various possibilities to store the hydrogen for later use: Liquid and gaseous hydrogen can be stored in a pressure vessel, hydrogen can be adsorped on large surface areas of solids, and finally crystal lattices of metals or other compounds can be used as the storage system, where hydrogen is dissolved either on interstitial or on regular lattice sites by substitution (SvW06, San99). The latter process and its reversal is called hydriding respectively dehydriding. The subject of this proposal is the modeling and simulation of that process. The main problem of a rechargeable lithium-ion battery is likewise a storage problem, because in a rechargeable battery, both the anode and cathode do not directly take part in the electrochemical process that converts chemical energy into electrical energy, rather they act as host systems for the electron spending element, which is here lithium (Li). During the last month the applicant developed and exploited a mathematical model that is capable to capture the storage problem of an iron phosphate (FePO4) cathode, where the Li atoms are stored on interstitial lattice sites (DGJ07).
Das Projekt "SILVIA - Sustainable Road Surfaces for Traffic Noise Control" wird vom Umweltbundesamt gefördert und von Bundesanstalt für Straßenwesen (BASt) durchgeführt. The first objective is to develop a classification procedure combined with a conformity-of-production testing method. It will start from existing measurement methods, improve some of them and possibly develop new ones. The second objective is to test and specify road construction and maintenance techniques that would achieve satisfactory durability of the acoustic performances while complying with other requirements of sustainability like safety, pollution and mobility. The third objective is to develop a procedure for cost/benefit analysis of noise abatement measures. The fourth objective is to issue a 'European Guidance Manual on the Utilisation of Low-Noise Road Surfacing' to help decision-makers to rationally plan noise abating or preventing measures integrating low-noise surfaces with other noise control measures. Prime Contractor: Belgian Road Research Centre; Bruxelles; Belgie.
Das Projekt "Improved Building Integration of PV by using Thin Film Modules in CIS Technology (BIPV-CIS)" wird vom Umweltbundesamt gefördert und von Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg durchgeführt. Objective: The results of the project will improve and widen the potential for the integration of solar (PV) energy systems into existing buildings. Special attention will be paid architectural and aesthetic questions. Building integration of PV systems in most cases leads to a 'high tech' and 'modern' appearance of the building. This is caused by the typical window-like surface of most conventional PV modules. Regarding however that90Prozent of the building stock consists of longer existing, that means 'old fashioned' buildings, it is evident that anaesthetically satisfying building integration of PV needs a lot of good will and creativity from planners and architects. In many existing building integrated PV systems the modules contrast with the building and its surroundings. A European survey on the potential and needs for building integrated PV components and systems will identify the basis for the development of modules away from the glass / window-like appearance. In the project PV roof tiles, overhead glazing and facade elements based on CIS thin film technology will be developed and investigated which have a modified optical appearance for better adaptation to the building skin. One of the ideas is optical decoupling of substrate and cover glass. A complete roof tile system with thin film cells adapted to the visual appearance of conventional roof tiles and innovative connection and mounting will be developed. The work includes prototype fabrication and tests according to relevant standards and subsequent performance tests. Novel overhead glazing includes semitransparent thin film modules optimised for daylight transmission. The backside appearance will be modified in order to represent the visible inner part of the building skin. For overhead and insolating glazing an invisible interconnection and for PV roof tiles a low cost connector will be developed. Project results will be systems ready for industrial production.
Das Projekt "Effects of biochar amendment on plant growth, microbial communities and biochar decomposition in agricultural soils" wird vom Umweltbundesamt gefördert und von Forschungsinstitut für biologischen Landbau Deutschland e.V. durchgeführt. Biochar has a great potential to ameliorate arable soils, especially those that are low in organic matter due to intensive use or erosion. Biochar is carbonised organic material with high porosity that brings about changes in physical, chemical and biological soil functions. Biochar amended soils show a higher water and cation exchange capacity with reduced leaching and enhanced availability of plant nutrients. The microbial biomass in biochar amended soils is enhanced and more diverse. Biochar is stabilised organic material, which is likely to remain for hundreds of years in the soil. Photosynthetically fixed atmospheric CO2 stabilised in biochar may thus act as a direct carbon sink and help to mitigate climate change. As feedstock and production conditions produce different biochar qualities predictions of effects in soil need to consider biochar and soil properties case by case. To date biochar has been approved to ameliorate highly weathered tropical soils with positive effects on crop growth and yield. Distinct microbial groups were reported to be enhanced in soils but if this depends on the particular soil or biochar or a combination of both is an open question, especially in temperate climates. Likewise, it is not known if microorganisms colonising biochar surfaces are responsible for its mineralization or if they just use the new niches provided. The aim of the proposed project is to investigate the influence of two biochar types on soil-plant systems by determining i) soil nutrient availability, plant growth and nutrient uptake, ii) structure and function of soil microbial communities, iv) the decomposition and fate of biochar in soils. We will use two loessial soils from the well-known DOK-trial with different soil organic matter content. Other soils from the region will be selected to provide a wider range of soil quality, in particular pH. The biochars will be produced by pyrolysis and hydrothermal carbonization (HTC) from the C4-plant Miscanthus gigantea. Pyrolysis derived material has bigger pore sizes due to the evaporating gasses and is commonly alkaline, whereas the HTC derived biochar has a finer pore size, a much higher oxygen content and more acidic functional groups.
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