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2094 Uppsatser om Soil microorganism activity - Sida 2 av 140
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.
Hur en ökad marktemperatur påverkar fotosyntes och markrespiration i en boreal skog
During the year of 2008, a powerful earthquake hit the southern part of Iceland, which changed the geothermal conditions in the area around the city of Hveragerdi. Elevated soil temperatures in a nearby forest plantation have contributed to a unique opportunity for researchers to study how an increased soil temperature affects the boreal forest ecosystem, something that partly can be connected to the climate changes which are happening today. The boreal forest is representing a carbon sink and a buffert for the emissions that occurs. Changes in this ecosystem will for that reason contribute to major impact for the global carbon cycle. To study the impact of how elevated soil temperatures affects different processes in a plantation of Sitka spruce, studies were made on the photosynthesis of the trees and the respiration from the soil.
Downward migration and transfer to plants of radiocaesium in Scottish soil profiles : a comparison with earlier studies
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.
Modellerade och uppmätta kväveflöden i energiskog som bevattnas med avloppsvatten
The aim of this essay was to study the nitrogen flow in two willowplantations, at different locations in the south of Sweden, that wereirrigated with sewage. The study was also performed to compare thedifferences in nitrogen flows between two years, 1998 and 1999. The studywas made in three parts. First, the denitrification activity was measuredusing the acetylen inhibition method. Second the nitrogen flow, as well asthe water- and heat flows, were modeled through the SOIL-SOILN-modelThird; the nitrogen flow was calculated to compare with the results fromthe model.The results from the measurements were then compared with the resultsfrom the SOILN-simulations to detect differences in the denitrificationrate.
137Cesium i myrsamhällen i Gävleborgs län 24 årefter Tjernobylolyckan
24 years have passed since the Chernobyl accident when radionuclides were spread over largeareas of Europe, including the Scandinavian countries. Today, measurable activities of 137Csare still observed in many Swedish ecosystems.Ants (belonging to the order Hymenoptera) are social insects which collect organic materialfrom a large area around their nests. This study focuses on the 137Cs activity in ant nests andthe cesium accumulation in these nests. The aims were (1) to estimate the 137Cs fall-out in1986, (2) estimate the radiation exposure of ants and (3) find how 137Cs is distributed in an anthill. Seven ant hills (occupied by the species Formica polyctena) were studied near the villageof Hille, situated north of the city of Gävle in central Sweden.
Bok- och grankonkurrens i Sydsverige - markegenskaper och naturlig föryngring :
In southern Sweden, beech (Fagus silvatica) and spruce (Picea abies) are two species with similar demands on soil properties. With increased global warming and high acid deposition the future may bring larger areas were the two species are overlapping, competing for the same soil. The aim of this study was to compare spruce and beech concerning distribution, cultivation and soil properties. From available data comparisons were made between spruce and beech forests in Sweden. Soil analyses were made on samples from beech forest in southern Sweden, with and without natural regeneration of spruce.
Glava glasbruk : En undersökning av föroreningar i mark- och vatten samt ansvaret för dessa enligt miljöbalken
The Swedish industrial society has left several areas with contaminated soil and water which today is of danger for the environment and human health. One of these areas with contaminated soil and water is the region where the former Glava glassworks operated during 1859 to 1939. The main object in this study has been to study the responsibility for the contaminations according to the Environmental Code. The method used is a qualitative content analysis of relevant literature to answer the following questions:What types of contaminations can be found in the area of Glava glasswork and what health issues can these cause?What kind of activity has been conducted in the area that have caused the contaminations in soil and water?According to law, what are the responsibilities for the contaminations in soil and water at Glava glassworks?The contamination in the region has been confirmed to originate from the glasswork due to the environmental engineering survey made in the area in 2009.
Metodutveckling för analys av klorfenoler i jord samt analys av förorenad jord från ett sågverk
In this final thesis, an existing method for analysis of chlorophenols (CP) in bottom sediments has been updated and adjusted for analysis of chlorophenols in soil. The covalent bonds between the chlorophenols and the soil matrix were broken through basic hydrolysis and the chlorophenols were then separated from the water phase through addition of sulphuric acid followed by ether extraction. The chromatography was improved through extractive acetylation of the chlorophenols.The updated method was then applied on soil samples from a contaminated area (a former sawmill in Hyttsjö, Östergötland, Sweden).The analyse was preformed by GC/MS with respect to 2-MonoCP, 4-MonoCP, 2,4-DiCP, 2,6-DiCP, 2,4,6-TriCP, 2,3,4,6-TetraCP and pentachlorophenol (PCP).Contamination of chlorophenols in nature can be explained by the former use of wood preservative chemicals based on chlorophenols. In the 1960s and the 1970s these chemicals were used in Sweden, but due to their toxicity they were banned by the Swedish government in 1978.In Hyttsjö a pentachlorophenol-based product named Santobrite was used for several years. The concentration of PCP in the soil samples from Hyttsjö varied from 0.2->1.8 ng/mg dry substance.
Förskolebarns motoriska utveckling : -Hur en förskolegård bör utformas för bästa tänkbara utveckling av barns motorik
The purpose of this study was to interview different groups of people (preschool teatcher, parents and theire childen) involved in preschool about their view on outdoor activity and children´s motoric development, and how a preschool yard should be designed to promote childrens development.All parties regard outdoor activity as very important for the development of children. They also think that the outdoor environment today is good but that it could be improved by including some trees and hills. The yard should also contain soil, sand, clay and water. The children prefer grass on the ground over other substrates. This study also gives good indications to decision makers how to build new or to reconstruct pre-school yards in the future..
Siktning som saneringsmetod för metallförorenad mark
Toxic metals contaminate soil worldwide and thus serve as sever environmental threat. Therefore the purposes of this study were to investigate in which soil fractions that different heavy metals (Fe, As, Cu, Zn and Pb) could be found in contaminated soils and if it is possible to use sieving as a method for decontamination. Soil samples were collected from three different locations, the Nasa silver mine, the Blaiken-mine and Svalget environmental station. The samples were oven dried and later on sieved into six different fractions 8mm, 4 mm, 0.5 mm, 0.250mm, 0.063 mm and <0.063 mm. The fractions 4 mm, 0.5 mm and <0.063 mm from each location were analyzed in an x-ray fluorescence detector.
Fysisk aktivitet hos personer med metabolt syndrom
A quart of the of the adult population worldwide havemetabolic syndrome. A sedentary lifestyle, low physicalactivity, combined with wrong eating habits, stress,smoking and psychosocial factors, are the main causes ofdevelopment of the metabolic syndrome. The purpose ofthe literature review was to illuminate the physicalactivity in persons who have the metabolic syndrome, andwhat sort of advice a nurse use in the promotion ofphysical activity. The study was conducted as a literaturereview, including 15 scientific quantitative articles. In tenarticles, the focus was on physical activity at themetabolic syndrome, and five articles focused on variousforms of counselling for physical activity.
Hur skattar överviktiga barn och tonåringar sin aktivitetsnivå? : En jämförelse mellan aktivitetsdagbok och accelerometer
Objective:This study aimed to investigate the correlation between physical activity level (PAL), measured with activity diary and accelerometer, among overweight and obese children and adolescents. The aim was also to study differences in PAL between girls and boys.Design:55 children and adolescents, whom been subjected to a physical activity registration with a physical activity diary and accelerometer during three or four days, were included in this study. From the data received from the children?s journal records PAL was calculated and compiled for statistic analysis.Results:The results of the study showed that the children underestimated their physical activity level when measured with activity diary, in comparison with the physical activity level measured with accelerometer. Differences between girl and boys PAL values were not statistically significant, although the girls PAL values from the accelerometer, but not from the activity diary, reached a moderate activity level according to Nordic nutrition recommendation.
Tankar om plöjningsfri odling :
The margin in crop production is more and more less and it forces the producer to check
out how to reduce the cost of establishment of new crop. One way to reduce the cost in
establishment is to begin with plough less farming. It saves money and time compares to
conventional soil preparation with plough and harrow.
Not all soil types are god for plough less farming and should be continued with
ploughing (mainly light soil), but other soil types working very well with plough free
farming.
If you want to success with plough less farming you have to think in new lanes. One of
the things you have to think about is to not grow too much cereal after cereal. Low
stubble is important when you harvest the crop and also to spread and chop the straw
well.
I have in this work interviewed some farmers and farm advisers in Östergötland to see
which thoughts they have about plough less farming.
Jordbearbetningsstrategier på hösten inför vårsådd på tyngre lerjordar :
It is important for today?s farmers to minimize the costs for crop establishment, because
of decreased prices and support from the EU. Farmers, who plow in autumn on heavy
clay soil, often do some kind of tillage in autumn to get better soil structure before
spring seeding. This is especially important when growing small seed crop, e.g. sugar
beet and oil plants.
Soil fertility status and Striga hermonthica infestation relationship due to management practices in Western Kenya
Striga hermonthica, a parasitic weed, has long been believed to be correlated with the
declining soil fertility status. However scientists have recently come to question this statement
since some recent studies have shown contradictive results. To investigate whether soil
fertility status and infestation of Striga hermonthica were correlated and the impact of it were
caused by farmer management, 120 farmers in Western Kenya, where Striga hermonthica
infestation is prone, participated in this study. In three districts with two sub-locations each,
farmers answered a structural questionnaire and identified two fields, one with high and one
with low soil fertility. These fields later came to be the basis for this study and soil were
therefore also sampled from them.