Today it is common to spray against most weeds by using very expensive weed-killers. The goal for every farmer is to have as low costs as possible for their use of machines and weed-killers. Therefore it is in everyones interest to find other methods to fight the weeds. Finding a way to reduce the rise and growth of weeds already at the preparation of the soil would lower the number of laps over the field and also decrease the amount of weed-killing dose. Tests show that by harrow in the dark it is possible to reduce the population of weeds with up to 60%, but the normal reduction would be about 20-30%. To verify the results above we made tests by using two different methods of preparing the soil. We tested ploughing and harrowing in daylight and during night. Later we checked the number of different weeds in areas prepared in daylight and during night. By studying the results from the different methods used we found a considerable reduction of some kinds of weeds in areas prepared during night..

Forest streams and the associated riparian zones are sensitive to disturbances and changes that occur within these riparian areas. Particularly sensitive are small streams of low order, which will have large impacts down-stream. The disturbances that occur in the riparian zones are reflected quickly in the stream. Driving with forestry machines in the riparian zone will have detrimental effects to the soil and water. Driving the machines will lead to changes in the mineral soil composition, resulting in the reduction of porosity, less infiltration, compaction, and an increased bulk density.

The purpose of this research is to survey and describe some science teachers? conceptions of which assessment criteria they use at the marking process. Questions which are relevant for this research are the following: 1. Which assessment methods form the basis for science teachers? marking process? 2.

Reduced tillage has increased in Sweden during several years, primarily to decrease costs andincrease efficiency in crop production. Despite this, mouldboard ploughing is still the mostcommon primary tillage method on most farms. The aim with this thesis was to compare theuse of pesticides and the occurrence of weeds on ten farms in Skåne and ten farms inMälardalen that use different soil tillage systems. The object of the study was also to clarifywhy the farms had chosen their specific soil tillage system and the consequences it has had onweed occurrence and use of pesticides. The result showed a slightly higher use of pesticideson the farms that use reduced tillage.

Erasteel Kloster AB Söderfors have been commissioned by the county administrative board in Uppsala län to make an inventory of possible contaminations in theirs industrial- and landfill areas on the basis of the Swedish Environmental Protection Agency?s; ?Method of Surveying Contaminated Sites-phase 1? (MIFO-fas 1). The inventory starts with maps and archive studies, place visits and interviews, and finally a risk classification is done. A risk classification is a compilation of four categories; pollutant toxicity, contamination level, possible spreading condition of the pollutant, sensitivity and protection value of the environment. In this paper five partial areas (Holmen- and Jörsöområdet, Järnsvampsområdet, Ingsådeponin, Östra verken and Myrområdet) have been described from a historical point of view. Only parts of four areas have been risk classified (Holmen- and Jörsöområdet, Järnsvampsområdet, Ingsådeponin and Östra verken), due to that the other areas isn?t own by Erasteel Kloster AB. Holmen- and Jörsöområdet Holmen- and Jörsöområdet have during the entire activity time been carried out as the production core in the company.

During my education I have frequently noticed that pupils do not like science or find it hard and dull. The purpose with this investigation is to find out how pupils experience their science education and if they can understand the arguments for studying the subject at school.I have made a questionnaire study among pupils in grade 8 and 9. After analyzing their answers I have interviewed some of the pupils to get answers on further questions.The investigation resulted in conclusion that pupils have hard to connect their science-education to their everyday lives. The most important element in forming the pupil?s opinions about science is their relation to the teacher and how the lessons are set-up.The following questions will be answered in this paper:Do pupils understand why they have science at school?Can the pupils see the use of scientific knowledge in their everyday life?How do pupils look upon their science education?.

Eutrophication of the Baltic Sea is a serious problem. A major contributing factor is diffuse losses of phosphorus (P) from agricultural land in surrounding countries. In order to estimate P losses, environmental monitoring of small agriculture-dominated catchments is being carried out in most of these countries. Evaluation of the risk of P leaching to waters is usually based on chemical tests originally developed to quantify the amount of soil P available for plant production. The tests are performed in different ways in the different countries and a number of different extraction agents are in use.

This paper deals with the question of when hill forts ? or enclosed mountains ? were built and to what purpose, by examining two enclosed mountains (RAÄ 78 and 79) in Grödinge parish in the province of Södermanland. A phosphate analysis was conducted to trace anthropogenic activities. The analysis showed only a slight elevation of phosphate content in the soil. A histogram indicated that the elevations were not normally distributed, which could suggest that they were caused by anthropogenic activities.

This essay describes the philosophy of science that Thomas Kuhn puts forth in his work The Structure of Scientific Revolutions. The question is, does his description of the scientific paradigm work as well today as in the examples he gave in the book?The conclusion is that there are certain factors that make for a number of differences between science today and, for example in the seventeenth century. There is also a growing theory or vision of a post normal science laid developed by among others Jerome Ravetz. This theory or vision is an idea of a science close to peer-communities and fast as well as critical decisions involving opposite values..

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..

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.