In order to reduce greenhouse gas emissions from human activities fossil fuels will have to be replaced with renewable energy alternatives, such as bioenergy. Sweden has a great potential to produce bioenergy derived from forest products and there is currently a great interest within Sweden in using stumps for bioenergy production. However, the environmental consequences of the method need to be investigated before stump removal can be performed on a large scale. Swedish forest soils contain large carbon pools and a different land use may change conditions so that soils that presently act as sinks of carbon could potentially turn into sources of carbon release instead. This study investigates the initial effects of stump harvesting on the emissions of three greenhouse gases, carbon dioxide, methane and nitrous oxide. The emissions were measured from the soil surface in a Norway spruce forest located in the southern part of Sweden.

There is a great need to reduce nutrient leaching from arable land into lakes and oceans. By using several different types of models it has previously been possible to describe nutrient losses in a catchment area with a minimum unit of sub-catchment level. At present, it is instead desirable to model a smaller catchment with an opportunity to re-connect the results to the corresponding fields in the catchment. Such models already exist but they are not fully able to properly describe Swedish conditions and land characteristics in our region.With the approach of creating such a model, SLU has developed a project with this work as its first stage. The model is expected to be created under the working name SWE-model which stands for Soil Water Environment and is in this first stage supposed to apply the SOIL model in catchment scale. During the procedure to describe the first step in the process of developing such a model adapted to Swedish conditions and which works in the catchment scale with an area of about 10-30 km2, focus has been set on calculating the transport of water flow from different hydrological response units. Regardless of the processes occurring in the soil after the water has been added, it is assumed that all the water which flows from each simulated unit is drained.In the first step the hydrologic response units were identified based on land use and soil type in the study area. With the help of a script with functions that retrieve and transform data, certain units were chosen for simulation. The script was also created in this project. Finally, the model results were aggregated and summarized for each unique unit, for each sub-catchment, and also for the whole catchment.From the results it is possible to see similarities in the flow dynamics between modeled and measured data. The efficiency coefficient has been calculated to correspond to the mean of the measured values for the whole simulation period. With an automated calibration process the model should be able to perform better. The volume error gives an indication of overestimation from the model..

Denna rapport redovisar ett examensarbete på Civilingenjör och Lärarprogrammet på KTH och SU.Examensarbetets syfte är att öka förståelsen för och kartlägga hur olika presentationsmodelleruppfattas påverka intresset och möjligheten att ta till sig kunskapen om mekaniken i fjädrandekonstruktionselement (FKE). Tre olika presentationsmodeller har kartlagts därpresentationsmodellernas kommunikativa angreppssätt har varierat mellan auktoritativ ochdialogisk. Presentationsmodellerna som kartlagts är:? Seminarie utifrån problembaserat lärande? Seminarie utifrån casemetodiken? Auktoritativt seminarieGenom deltagande observation och intervjuer har deltagarnas uppfattningar om de olika KPM, vadavser intresse och möjlighet att ta till sig kunskap, testats och kartlagts och studiens slutsatserredovisats. Denna studie utförs inom ämnet FKE och målgruppen för presentationsmodellerna ärvuxna personer med grundläggande kunskaper i mekanik.Resultatet av studien visar att möjligheten till inlärning och intresset ökar om det kommunikativaangreppssättet dialogiskt betonas.

Acid sulphate soils is a wide spread problem along the northern coast of Sweden. This is causing great damage through low pH and leaching of metals out into the streams. These soils are estimated to be found in several places in Sweden but also in many other areas in the world. One of these areas in Sweden that are believed to contain these sediments is Mälardalen. The purpose of this study is to evaluate the extension of the acid sulphate soils in this area.

Better, more efficient fertilizers with great productivity and economic returns are needed, but it is important today to find fertilizers that are also sustainable. It is also important to carefully monitor their impact on the environment, including potential side-effects. In this context, the microbial communities that carry out numerous essential functions contributing to a functional ecosystem are of particular interest. The present study is a complement to a pot experiment that investigated the potential of different waste products for use as fertilizers and how they affect the microbial community. In the pot experiment, the clearest treatment change in microorganism community function was found in the fully fertilized treatment used as a positive control. The question was whether this was indirect, i.e.

The aim with this thesis is to make a comparison between forcing tulips in a hydroponic system and the forcing off tulips that have been planted in soil. The results are mostly based on interviews with six Dutch and one Swedish tulip forcer and the managing director at the Horticultural Research Centre, Proeftuin Zwaagdijke, in the Netherlands. There are benefits and disadvantages with both methods. Tulip bulbs planted in soil seem to get a brighter colour after forcing, compared with those forced ?in water?.

The purpose of this study was to build a database for point-bearing piles in dense noncohesive soil, predominantly moraine. Further, the database was analysed and areas with difficult geotechnical conditions was identified.The database includes for point-bearing piles driven to refusal in moraine. Piles with mainly shaft friction have been excluded. Only concrete piles have been included. Geographically the database covers almost all geotechnical conditions of Sweden.

In a column experiment the effect of three different biochars on nitrous gas emissions, nitrogenretention and water filled pore space (WFPS) were studied in a Swedish sandy soil, classified as aCryopsamment. Ammonium retention was positively correlated, while KCl-extractable ammoniumwas negatively correlated, with the specific area of the biochars. The question was raised whether thenegative correlation between extractable ammonium and biochar specific area reflects the amount ofammonium present in the soil or its extractability from the biochar, and whether methods forextracting soil mineral nitrogen, like KCl-extractions, have to be modified for application on biocharamended soils. There was a tendency of increased nitrate retention and KCl-extractable nitrate withbiochar and KCl-extractable nitrate was positively correlated with the specific area of the biochar. pHwas higher for all biochars compared with control, although the differences were not significant, andWFPS was lowered by biochar addition, significantly in one case.

This study investigated potato growing in beds as an alternative to conventional ridges.It was based on results from field trials on bed-grown potatoes carried out by Halland Rural Economy and Agricultural Society in 2007, studies of literature and interviews with farmers with experience of bed growing of potatoes. Due to their shallow root system, potatoes are one of the most drought-sensitive crops. Potatoes are often grown on sandy soils with poor water-holding capacity. Factors such as total yield, tuber size distribution and quality defects are negatively affected when water becomes insufficient. Wide beds have a more flat top which leads to more uniform water infiltration. Further on, beds have lower soil surface area due to its shape, and therefore, retain water more efficient. In the field trials, which were carried out at the Stjärnarp Estate near Halmstad, potatoes were grown in beds alongside a conventional ridge-grown crop.

This thesis aims to present the essential background on how to perform climate changeimpact assessments, and to present the results from a climate impact assessment on waterbalance and nitrate leaching for an arable Swedish soil. The soil is a sandy soil in southwesternSweden, grown with spring cereals. This study is meant to be a benchmark example,and cannot be seen as a regional or national assessment for Sweden, rather as an approachto present and analyze the most important parts of these kinds of assessments.A dynamical simulation model (COUP, Jansson and Karlberg, 2004) was used for thisstudy. The model was parameterized and calibrated against data from an experimental site,located in Mellby in Hallands county, south western Sweden. Measurements were carriedout between 1st of April 1988 and 1st of April 1991.

This thesis aims to present the essential background on how to perform climate changeimpact assessments, and to present the results from a climate impact assessment on waterbalance and nitrate leaching for an arable Swedish soil. The soil is a sandy soil in southwesternSweden, grown with spring cereals. This study is meant to be a benchmark example,and cannot be seen as a regional or national assessment for Sweden, rather as an approachto present and analyze the most important parts of these kinds of assessments.A dynamical simulation model (COUP, Jansson and Karlberg, 2004) was used for thisstudy. The model was parameterized and calibrated against data from an experimental site,located in Mellby in Hallands county, south western Sweden. Measurements were carriedout between 1st of April 1988 and 1st of April 1991.

The short term effect of phosphorus in sewage sludge was investigated to establish howmuch of this a farmer can grant him- or herself, if using sewage sludge as a phosphorusfertilizer. Possible differences in plant availability between sludge phosphorus precipitatedby iron, aluminum or calcium integrations were studied in a sandy soil at two pH levels.The sludges were analyzed using pot and incubation trials. As the intention was to investigategrowth limitation due to phosphorus deficiency, a soil with low phosphorus supplywas chosen as well as a low phosphorus application rate. Sludge corresponding to 12kg phosphorus per hectare was applied. Treatments fertilized by sludge were compared totreatments where 0, 6 and 12 kg phosphorus per hectare from mineral fertilizer was applied.Every treatment was replicated six times.

Following the accident at the nuclear power plant in Chernobyl in 1986, great volumes of137Cs were distributed over large parts of the former Soviet Union and Europe. Over Scotland,radiocaesium was deposited as wet deposition. Due to the relatively long physical half-life of30 years, there are still measurable activity concentrations in the natural environment. Thisstudy was made on two organic soils, Knockandy Hill and Rora Moss, situated in the easternpart of the central highlands of Scotland. At these two sites, studies on migration and transferbetween soil and plants were conducted.

When investigating mechanical problems it is often more convenient to deal with scalars rather than vectors. In this project methods stemming from the field of analytical mechanics, which lets one derive the equations of motion using scalar quantities instead of vectors, have been used. Two mechanical problems were investigated, a double pendulum with a spring and particles orbit in a sphere. The equations of motion of the two systems were derived with the assistance of computer algebra, using Maple and the external package Sophia. The systems were investigated with regard to periodicity and conserved quantities..

Sewer trenches usually contain material with a higher hydraulic conductivity then the adjacent soil. Thus they can serve as paths of preferential flow in a polluted area. Wastewater from factories can also leak from wastewater pipes and pollute the soil in the sewer trenches.The purpose of this project was to investigate pollutions in sewer trenches and in sewer pipes in the industrial area of Köpmanholmen, 20 km south of Örnsköldsvik in the north of Sweden. To make an estimation concerning the potential of transport of pollutions in sewer trenches, hydrological calculations were performed.Leakage to any greater extent did not seem to be a problem in the area. This is the case both for the concrete and the wooden pipes that have served as factory wastewater pipes.