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2094 Uppsatser om Soil microorganism activity - Sida 3 av 140

Where has the fertilizer gone? Closing the nutrient budget for a eucalyptus fertilization experiment in southern China

An increasing demand for wood products in China has resulted in large areas invested in fast-growing tree plantations of eucalyptus. Eucalyptus plantations are often associated with an intensive management including fertilization. By understanding the effects of fertilization and where in the ecosystem nutrients are accumulated a more sustainable forest management could be achieved. In this study, a nutrient budget including all biomass and soil components was created for Eucalyptus urophylla. The examined nutrients were nitrogen, phosphorus and potassium.

Marktillstånd och borbrist på åkermark planterad med gran i Västerbottens län :

This study was made on former agricultural areas that had been planted with spruce or pine, in the county of Västerbotten. The goal of the project was to investigate suspected deficiency of boron in these areas. Several objects have been reported for possible deficiency and some of these have the characteristic symptoms of boron-deficiency. The hypotheses are that 1) Boron deficiency is present at several of the investigated objects. 2) Planting of forest on cultivated postglacial sediments leads to a successive podzolisation with a decreasing content of organic matter in the mineral soil, due to decomposition, and a decreasing pH in the soil, even on locations that have been added lime. To be able to confirm or reject the hypotheses a number of tests were performed.

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.

Helicobacter spp. i digestionskanalen hos svenska katter : en metodologisk och klinisk studie

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.

Effekt på mark och gröda av olika bearbetningssystem, med och utan CTF

Swedish agriculture has gone through big changes in the latest 60 years. The farm sizes have increased, which has led to raised tractor and machinery sizes and therefore increasing problems with soil compaction. A method to reduce these problems is to implement controlled traffic farming, CTF. All field operations are then concentrated to specific tracks by using GPS guidance. The aim of this work was to study how the tillage regime, with or without CTF, affects the soil, with the main focus on macroporosity. In Säby close to Uppsala, and Alnarp close to Malmö, randomized block trials has been carried out, and the data has mainly been taken from these trials.

Utvärdering av fosforläckageefter stallgödsling med hjälp av lysimeterteknik : Evaluation of phosphorus leaching aftermanure application using lysimeter techniques

Based on laboratory studies with lysimeters, the concentrations of dissolved reactive phosphorus(DRP) and particulate phosphorus, which is the main part of other P (OVRP), has been studied inpercolating water. The experiment was conducted through irrigation of small soil columnscontaining clay topsoil from an experimental field in Västergötland. Three rain simulations wereconsecutively performed. DRP concentrations in the percolating water ranged between 0.2 - 0.3mg·Lclearly related to the phosphorus concentration in the soil, measured in a soil extract ofammonium lactate (P-AL). Concentrations of OVRP were relatively low and ranged between0.12 and 0.16 mg·Lwas not proven and the experiment may reflect how a relatively slow percolation of water mayrelease DRP.

Ants and termites in small-scale plantain farms in Uganda : a comparison between agroforestry and non-agroforestry farms

This study was conducted in Kkingo district, west of Masaka, Uganda. It compared soil macrofauna abundance in non-agroforestry farms with that of agroforestry farms. The agroforestry farms had participated in the Vi Agroforestry´s program between 1995 and 2006, and continued on their own after 2006, when Vi Agroforestry left the area. The soil macrofauna is important for soil structure and processes that are contributing to soil organ-ic matter decomposition and nutrient mineralization. They are also predators of potential pests.

Fosforläckage från växtodling - orsaker och ågärder :

Phosphorus is essential to all plants and is taken up from the soil as the ion H2PO4 - (and to some extent HPO42-). Plant availability depends on, among other factors, the soil pH. In order to provide for plant available phosphorus, it is applied as mineral fertilizers and farmyard manure. However, that causes phosphorus leaching from arable land to surrounding surface waters and lakes and contributes to the eutrofication. There are three types of soils in Sweden that are at higher risk of contributing to phosphorus leakage.

Droppbevattningens inverkan på kvalitet och kvantitet hos Solanum tuberosum L i jämförelse med konventionell spridarebevattning :

A literature study and a field trial have been carried out in order to investigate the physiological response of potato plants to different soil moisture levels. Higher yield, quality and number of tubers can according to the literature be obtained if constant high soil moisture is kept during major parts of the growing season. A field trial was set up where drip irrigation was used as an alternative to conventional irrigation techniques to maintain high and constant soil moisture. The application of water in the drip irrigated area was monitored and adjusted on a daily basis so that the soil moisture stayed as close as possible to the recommended level. The sprinkle irrigated area was irrigated according to traditional practices with approximately 35 mm every 7th to 10th day depending on the whether.

"Annan finansiell verksamhet" - En tolkning i ljuset av CFC-lagstiftningen : En tolkning i ljuset av CFC-lagstiftningen

The initial provisions concerning CFC-legislation were introduced 1990 and has since been subject to several revisions and adaptations. The fundamental purpose of the CFC-legislation is to prohibit and prevent tax evasion undertaken by such companies that own other foreign companies where generated income is subject to low rates of taxation. The CFC-legislation aims to provide the Swedish government with an op-portunity to tax this income. This is important in order to prevent tax avoidance and preserve the integrity of the system of taxation within Sweden. In order for the CFC-legislation to be as effective as possible there must exist a clear way of defining which activity that is to be regulated within its scope.

Speglingar, reflektionens redskap för den kvalificerade samtalspartnern

The initial provisions concerning CFC-legislation were introduced 1990 and has since been subject to several revisions and adaptations. The fundamental purpose of the CFC-legislation is to prohibit and prevent tax evasion undertaken by such companies that own other foreign companies where generated income is subject to low rates of taxation. The CFC-legislation aims to provide the Swedish government with an op-portunity to tax this income. This is important in order to prevent tax avoidance and preserve the integrity of the system of taxation within Sweden. In order for the CFC-legislation to be as effective as possible there must exist a clear way of defining which activity that is to be regulated within its scope.

Bildskapande : En undersökning i hur pedagogerna på en förskoleavdelning ser på och bemöter barns bildskapande

This report describes a study of how educationalists, from one preschool group, approach to and respond to children ?s creative activity in preschool. To answer the survey ?s purpose I used four research questions, which is the following:-What function do the educationalists give the creative activity in the working?-How do they see the importance of thecreative activity for thechild and its development?-How doeducationalists considerthat theyrespond to the child's creative activity?-Is thereany norms surrounding creative activity in preschool?The theoretical base of the study is rooted in the sociocultural perspective, where creative activity and visual arts can be seen as mediating cultural tools. The method is a qualitative interview of five preschooleducationalists.

Geokemin inom osorterade cirklar : Analys av tungmetallers distribution inom jordprofiler tagna från Abiskoområdet, nordvästra Sverige

The Arctic region appears as a pristine remote environment, yet there is increasing evidence that it is greatly impacted by pollution such as lead (Pb) and mercury (Hg). In this environment deposition of Hg has increased threefold since the last industrial revolution. In this study five cryosolic soil profiles within non-sorted circles (NSC) in the Abisko region, northwest of Sweden, has been analyzed to improve our understanding regarding how pollutants are distributed within such type of soil. The soil samples have been analyzed with the use of X-ray fluorescence analysis (XRF), for the measurements of the total concentrations of e.g. lead (Pb) and zirconium (Zr).

Elementkoncentrationer i gran utmed en markfuktighetsgradient :

One key factor in silviculture today is sustainability. In order to achieve sustainability it may be important to restore lost nutrients to the forest after clearcutting. In order to calculate the removal, you need to know how much of different elements you will find in different tree compartments. The aim of this study was to investigate if the concentration of elements in different tree compartments of spruce (Picea abies (L.) Karst) were related to the moisture conditions of the site. Five plots at Risfallet (60º 21´ N, 16º 13´ E), was placed along a moisture gradient in a 40- year spruce stand.

Förändring av nitratläckage och växtproduktion från låglänt jordbruksmark vid en ny reglering av vattennivån i Mälaren

The water level of Lake Mälaren has been regulated since the 1940?s. A recentinvestigation suggests that the current regulation needs to be adjusted in order toprevent a decline in water level, salt water from infiltrating from Lake Saltsjön,and risk of floodings. In addition to these preventions, the new regulation couldpotentially effect the natural environment and agriculture practices in the lowlands that surround the lake. The new regulation proposal calls for an increase invariations in Mälaren?s water level during seasons, while the annual mean waterlevel will remain the same.

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