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525 Uppsatser om Soil Chemistry - Sida 1 av 35

Kvävestatus och risk för nitrifikation i två avverkade skogsområden i Halland

Nitrogen deposition leads to environmental damage in areas where the nitrogen deposition is high. Southwest Sweden receives an annual nitrogen deposition of up to 20 kg N/ha. Nitrogen that is not assimilated by the vegetation is accumulated in the soil, which may lead to nitrogen saturation and an elevated risk of nitrogen leaching. Nitrogen leaching from forest areas in southern Sweden has proven to be higher than from agricultural areas, which have been thought to be the main contributors to elevated nitrogen levels in rivers and lakes. The amount of nitrogen that leaches depends on the fraction of the total nitrogen in the soil that consists of nitrate, since nitrate is easily transported through the soil.

Grön kemi och hållbar utveckling : Laborationsdesign för gymnasium och högskola

This thesis is about sustainability within chemistry, the so-called, green chemistry. With this work  I seek to combine green chemistry with sustainable  development  and find methods for teaching green chemistry in a laboratory environement.  I have designed  and tested two labs with ingredients of green  chemistry and sustainable development in my study. I wanted to determine if my design model  leads to conception for the students. The students have through forms and interviews declared their perspective on the education and their conception. In a laboratory environment the pros of a laboratory way of work should be recognized.

Det löser sig! : Förberedelsens betydelse för gymnasieelevers lärande vid kemilaborationer

Laboratory work is a big part of chemistry education in high school. During our student training placement we have noticed that the laboratory work is not fully utilized to develop students´ chemistry knowledge. This problem made us want to investigate how the laboratory work in chemistry could be set, to become more meaningful for students. We introduced two preparation methods, and examined the outcome of students learning experiences and their acquisition of chemistry knowledge. This was examined both through surveys and observation.

Sjunkande pH i Västerbottens humuslager : en kvantitativ analys

Acidification is a central concept in the environmental debate. The effect of acidification of the soil is a matter of a decreasing amount of cations and thereby a decreasing ability to resist a supply of hydrogen ions to the soil. Acidification has gradually increased in the O horizon in Västerbotten over a 30-year period from the 1970th to the 1990th. The aim of this study was from inventories of The Swedish National Forest Soil Survey and The Swedish National Forest Inventory explain and quantify the acidification that has occurred in the O horizon of two regions in the north of Sweden. Data from SMHI, The Swedish Meteorological and Hydrological Institute, has also been used.

Fördjupad miljöriskbedömning av förorenade markekologiska system. : Integrering av kemisk, toxikologisk och ekologisk information.

AbstractThe research project Liberation, supported by the European Commission under the Environment and Sustainable Development Programme (Fifth RTD Framework Programme) aimed at developing a decision support system for ecological risk assessment of contaminated sites has proposed a tiered system including the triad method. This method integrates contaminant chemistry and bioavailability analyses with observed ecotoxicological effects in soil and groundwater. In this study the triad method was used to perform a risk characterization of a former surface treatment and metal industry, now used for the student union buildings of the Mälardalen University in Eskilstuna, Sweden. On the site, high concentrations of copper, zinc and nickel have been detected in the soil in a preliminary investigation of contaminant levels with XRF. For performing the risk assessment of the site according to the triad method, contaminant bioavailability, soil metal concentrations and soil toxicity were determined and an ecological assessment was carried out on four selected soil samples (one reference soil and three samples with low (B), medium (C) and high (D) contaminant levels). Contaminant bioavailability was measured through leaching (ISO TC 190/S7) and biouptake tests (DGT).

Askåterföring i Jämtland : biobränslets och askans innehåll av tungmetaller relaterat till markernas geokemi

Using biofuels from regeneration cuttings is becoming more common in Sweden. Ash from the combustion of biofuels contains many valuable nutrients and base cations. The Swedish Forest Agency recommends that ash should be recycled to clearings where biofuels have been removed, to avoid future impoverishment of Swedish woodlands. In Jämtland, in northern Sweden, a large quantity of biofuels are taken out from cuttings but ash recycling has not yet been tried. The aim of this thesis was to examine the conditions for ash recycling in Jämtland regarding to Soil Chemistry and heavy metal content in soil and biofuels.

Kvävemineralisering från stallgödsel beroende på olika grad av inblandning i mark

The impact of the distribution in the soil volume of two farm manures on the net mineralization and immobilization processes of nitrogen were studied in an incubation experiment. Cattle slurry and broiler litter were placed in the soil with three procedures for incorporation including placement on top of the soil (TOP), in the middle of the soil (MID) and mixed homogenously with the soil (MIX). During the two weeks of incubation, few significant differences in net mineralization were seen between TOP, MID and MIX. However, there was a tendency that MIX led to a larger net immobilization of N than placement at one point (TOP and MID). This is also the result in the literature.

Markskadefri avverkning - från traktplanering till plantering

This study is made for Södra skog and is concerning how to minimize soil damage from planning to plantation. The purpose of the study is from the respondent?s perspectives; their own ideas and approaches. What emerged from the interviews is that the communication between the different organization levels can be improved. It is also important to prevent damage on the soil and to have in mind that the process of planning tracks to plantation continues for a long time and because of that, the soil condition meanwhile will change..

Långsiktig förändring av fosforhalt och skördenivåer för jordar med höga P-AL-tal : en analys av försöksserien "Exploatering av höga fosfortillstånd"

The field trial Exploatering av höga P-AL-tal (Exploiting P in heavily P dressed soils) started in 1982-1983 and included seventeen study sites placed across Sweden. Each site included three treatments, one unfertilized control (A), one aiming at replenishment of harvest removal, i.e. fertilized with 15 kg P ha-1 year-1 (B) and one over-fertilized (C) with 30 kg P ha-1 year-1. In this thesis data from the five longestrunning study sites are analysed based on four hypotheses. The hypotheses stated that in soils with high P-AL values and a pH over 6.0 P-AL will not decrease over time in the control (A) or in the replenishment treatment (B), that P-AL and P-HCl in the top soil will increase at all sites for the over-fertilized treatment (C) and that yields will not decrease as long as the P-AL is above 12 mg P 100 g-1 soil. My conclusions from the analysis of data from the selected sites are as follows: - A pH above 6.0 cannot guarantee a stable P-AL value in an unfertilized but phosphorus-rich soil. - The P-AL of unfertilized soils decreased faster at lower soil pH than at higher pH. - In the replenishment treatment (B) the rate of P-AL decrease seems to fall at a pH of 6.5. However, the influence of the soil type cannot be ignored. - P-AL and P-HCl did not increase in all over-fertilized treatments.

Vinster med björkinblandning i granbestånd i syfte att höja markens pH-värde

The soil acidification and the pH-value of the soil have been discussed for many years. Many observations of the tree species effects on the soil pH have been done. We have discussed the effects on the soil surface pH-value with a birch (Betula spp. L.) admixture in Norway spruce stands (Picea abies L.).We have used data from the Swedish National Forest Inventory. We have also discussed how the wood production and the biodiversity can be increased in mixed stands, in according to the Swedish forestry act Skogsvårdslagen. Our sampling areas are located in Norrland, Sweden. The results show a significant correlation between an increased birch admixture and an increased pH-value of the soil.

Sol, jord och vatten. : Barns tankar om den ekologiska processen

Studies show that the interest and knowledge about science among teenagers is decreasing. They also reveal the difficulties to explain the ecological processes and that the ideas about the nature are collected from everyday life and early school years.The intention of this investigation was to find out more about children?s ideas and knowledge about the ecological processes and to compare these results with the curriculum.The method was a questionnaire and interviews with children in school year 1 ? 6. The aim of the studies was also to find out if any progress connected to age could be found, concerning understanding of the ecological processes.The results showed difficulties in achieving the predestined goals for biology and chemistry concerning ecology cycles and they differed a lot between the children. Often the learning process showed very little progress.

Miljöarkeologi i Umeå stads hamn och slagfältsarkeologi på Krutbrånet : Två fallstudier inom historisk arkeologi i Umeås 1800-tal

This master thesis deals with two case studies in environmental archaeology and battlefield archaeology focusing on two major events in the late history of the Swedish coastal town Umeå and its nearby village Sävar. Established in the early 1600's, Umeå was known for its export of timber and import of cereals. The town has suffered from numerous fires, the fire in 1888 being the most devastating. Few written records of the town remain from before the 1900's. The latest war in Sweden's history is documented in historical sources and took place at Krutbrånet, Sävar where the Swedish troops suffered defeat against the russian forces in 1809.

Strukturkalkningens möjlighet att hindra fosforutlakning : en litteraturstudie

The purpose of this essay is to find out if liming with Ca(OH2) and CaO can reduce leachingof phosphorus from agricultural land and the problem with eutrophication. This purpose alsoincludes getting knowledge about how to make the phosphorus retained in the soil and beaccessible for the plants. This essay is supposed to show if more research is needed in thissubject. There has not been much research about this subject and therefore the amount ofmaterial to study is limited in this literature review. The research reports that have beenstudied have similar results.

Olika metoder och tekniska hjälpmedel för att bestämma bevattningstidpunkt :

This examination work on studies and research in articles is mostly from other countries. The purpose of the examination work have been to find out if there are any means you can work with to find out when its time to start irrigation, how they works and if they are credible. In Sweden there is not many means for decide when it?s time to irrigate and how much water you should appear. Swedish farmers think they have so much experience that they don?t need techniques like this.

Soil carbon, pH and yield development in a long-term humus balance trial

Agriculture has to be performed in a sustainable way in order to sustain high yields and to support a globally growing population. Functional soil properties are fundamental for high yields and in order to achieve good soil conditions sustainable management is a key. Loss of soil organic material and increased soil acidity are problems associated with degradation of soils and hence less sustainable agriculture. In this thesis, the effect of different agricultural systems on soil organic matter, pH and yield was examined. The systems examined are a cereal system with straw removal or returning and a ley system, all with different nitrogen levels.

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