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258 Uppsatser om Mineral nutrients - Sida 13 av 18
Är kolrika jordar en källa till fosforläckage? : en sammanställning av data från 130 åkerjordar
Phosphorus (P) is an essential nutrient but a surplus could lead to eutrophication. Furthermore,
the minerals used to produce the mineral phosphate is a non renewable resource.
There are in other words several reasons to reduce the leakage of P and the agriculture is one important area to attend. The aim of this work has been to investigate if carbon-rich arable soils content contain more P than arable soils with low carbon content. Moreover it has been calculated if the carbon-rich soils could pose a risk of P leakage by comparing their delivery of P with the plant uptake. The work has consisted of compiling the results from former gathered and analysed soil samples of 130 Swedish arable soils.
The fractions of P considered are water soluble P (Pw), ammonium lactate-extractable P (P-AL), hydrochloric acid-soluble P (P-HCl), organic ammonium lactate-extractable P (Porg-AL) and inorganic ammonium lactate-extractable P (Porg-HCl).
Vårvetesorters effektivitet i användningen av kväve under den huvudsakliga tillväxtperioden
Crop efficiency in utilizing available nutrients is an important factor in increasing produc-tivity and reducing the environmental impact of agriculture. Nitrogen is the nutrient that plants need in the largest quantity and wheat, along with maize and rice, is the world's most cultivated crop. In this work, the Nitrogen Use Efficiency, NUE, during the major growth period, HTP, of twelve different spring wheat varieties, were examined. The NUE was calculated as the product of uptake efficiency of nitrogen, UN, and the conversion effi-ciency of nitrogen to biomass, EN. The purpose of this work was to find if there are varietal differences in NUE and its components among the twelve varieties and to link a high NUE to specific characteristics of the varieties.
Kaliumgödsling på torvmark - effekt på tillväxten hos planterade granar (Picea abies)
Peat lands are a great potential resource for increased forest growth in Sweden, there are approximately 6.5 million hectares of peat lands, whereof around 70% produce less wood than one m3sk/ha and year and are therefore classed as forest waste land. There are over 200 000 hectares of peat land that is already drained and wooded, and that may be suitable for fertilization. Forest production on peat soils usually requires drainage and fertilization. Dewatering requires ditching the area, so that the roots can have access to oxygen. Nitrogen is often abundant in the peat but other nutrients; especially potassium is in short supply. The purpose of this work was to examine the effects of potassium fertilization on the growth of spruces that were planted on drained peat land and how different amount of fertilizers affects the growth. Potassium deficiency is strongly growth inhibiting, since potassium is important for substance transport in the tree. Potassium is also important for the carbohydrate formation, and because increasing the sugar content of the cells constitutes a lower freezing temperature does potassium availability in the soil play a major role in the winter resistance of many species. Potassium is not found in any organic compounds in the tree, but is present in cell and tissue fluids. A fertilization trial was started in 1978 in Siljansfors Experimental Forest. The plots in the experiment were fertilized with different amounts of potassium and one plot was left without fertilization. All plots that were fertilized with potassium grew considerably better than the unfertilized plot. The difference in production between the unfertilized plot and the plot that received the most potassium was 7.2 m3sk/ha and year. The unfertilized plot can still be classified as waste land. The theoretical production capacity was estimated using a Swedish system for site quality estimation of wetlands after ditching (dikningsbonitering). The plot with most potassium produced after fertilizationaproximately in level with theoretical estimations. Key words: Peat land, Fertilization, Ditching, Growth, site quality..
Fosforavskiljning i reaktiva filter vid småskalig avloppsrening
An excessive input of nutrients to lakes and other water bodies has created a problem with eutrophication in Sweden. Untreated, or partially treated, domestic sewage is a major source for discharge of phosphorus (P), which is the nutrient most frequently responsible for eutrophication of most fresh waters and the Baltic Sea. The waste water can be cleaned by filter materials, which have a high P-retention ability and which after saturation may be used as fertilizers. Four potentially suitable filter materials were tested in batch- and column experiments in this study. In the batch experiments, the following materials were shaken with waste water in time series ranging from 5 seconds to 60 minutes: coarse (1-4 mm) and fine (0-2 mm) Polonite® (heated bedrock from Poland); Filtralite® (light expanded clay aggregates with limestone added before burning); water cooled blast furnace slag (BF-slag) and BF-slag mixed with 10% burned limestone.
Renbruksplan ? från tanke till verklighet
Renbruksplan (RBP) är ett kommunikations- och planeringsverktyg skapat för Sveriges samebyar. År 1999 genomfördes en förstudie och idag, 15 år senare, har 50 av Sveriges 51 samebyar påbörjat arbetet med renbruksplaner. Idag används RBP av renskötare för att planera sin dagliga verksamhet och som ett stöd i diskussioner med olika typer av markanvändare för att kommunicera och visa rennäringens verksamhet.
Vägen fram till dagens Renbruksplan startade redan under 1700-talet i och med gränsdragningen mellan Norge och Sverige. Renskötseln begränsades till Sverige och sommarbetet i Norge gick förlorat. Efterföljande århundraden fortsätter renskötselsamhället möta förändringar som påverkar dess form och utförande.
Inappetens hos katt ? omvårdnadsbehandlingar med fokus på beröring
Particular to the cat among our pets is its´ unique nutritional needs and metabolism. The cat cannot produce some nutrients by themselves and must get them through their diet. This means that the cat quickly can suffer from various diseases unless the nutritional needs are covered. In those cases where man is completely in control of the cat?s diet, the right knowledge is crucial for the cat?s wellbeing.
Analys av system för rening av avloppsvatten i en anaerob membranbioreaktor
The most common way to treat wastewater in Sweden today is by a combination of an activated sludge process and a chemical treatment. These processes are not very energy efficient and may not be the most environmentally friendly. That is why it is interesting to evaluate new alternative methods to see if they can be less harmful to the environment and help to a lower resource consumption. New techniques are tested in a pilot installation at Hammarby Sjöstad, Sjöstadsverket. To be able to evaluate these techniques in a wide perspective system analyses are conducted where different impacts can be considered, advantages and disadvantages in the systems.Five system structures for water treatment have been constructed in Matlab/Simulink in this study.
Sustainable phosphorus management of horse paddocks at Julmyra
Horse keeping is gaining an increasing interest in Sweden. During 2004 to 2010 the number of horses increased
with 10 - 20 %, and was estimated to be 362 700 in 2010. Julmyra Horse Center (JHC), situated in Heby municipality,
is a gated community for people sharing a large interest for horses and a vision of a sustainable horse
management has been formulated. This study evaluates how the horse keeping of today at JHC, and how an
expansion of the horse keeping may affect the risk of enhanced phosphorus load to the nearby lake system
Vansjön ? Nordsjön.
Metodik för bestämning av åkerdikens status : fallstudie av ett dike i Munktorps socken
Agricultural drainage ditches are links between fields, lakes and oceans, having the potential to transport e.g. sediment and nutrients. When in a good condition, drainage ditches can act as sinks for e.g. phosphorus and sediments and prevent eutrophication downstream.
The aim of this study was to determine the condition of one agricultural drainage ditch and to come up with suggestions for appropriate measures. The aim was also to determine
which of the ditch?s properties that were possible to evaluate visually, which processes they represented as well as which properties required complementary physical analysis.
This in order to contribute to the work of developing a method for determining the status/condition of agricultural drainage ditches.
Rötning av matavfall ? en studie av metanutbytet hos matavfall förbehandlat med skruvkrossteknik samt vid samrötning med bioslam från pappersbruk
Today's society is facing major challenges. In order to reduce the climate impact fossil fuels should be replaced with fuels that do not contribute to the greenhouse effect. The growing population generates organic waste originating from industry and households so called organic fraction of municipal solid waste (OFMSW). Through anaerobic digestion, waste can be utilized to produce energy-rich methane gas. In this way, waste can be a resource instead of a burden on society.
Avskiljning av ammoniumkväve och fosfatfosfor i reaktiva filtermaterial : skak- och kolonnförsök
In Sweden more than 400 000 private households have not yet sufficient wastewater purification. These effluent is considered as an increasing problem and many onsite purification methods have been studied. In this investigation, the method of reactive bed filters have been tested by column and batch experiments. Five different kinds of filter materials with reactive surfaces have been studied concerning their capacity to absorb ammonium and phosphorus from wastewater. The materials that were examined are Filtra N, wollastonite Filtra P, blast furnace slag and Polonite®.
Effektivisering av reservdelsförsörjningsprocessen: En studie av Boliden Minerals värdeflöde i reservdelsförsörjningsprocessen
I en värld med ökande globalisering utsätts företagen för mer och mer konkurrens. Vilket medför att företagen ställs inför högre krav på effektivitet och produktivitet för att skapa och bibehålla sin konkurrenskraft. För att upprätthålla effektivitet och produktivitet krävs emellertid underhållsarbete för att stödja de processer som ska möta kundens behov. Detta underhållsarbete medför därför ett behov av att anskaffa reservdelar, en process som bör bedrivas effektivt för att undvika produktionsstopp.Studien har genomförts på Boliden Minerals AB i Kristineberg, vars reservdelsförsörjningsprocess inte upplevts som optimal. Detta medförde att studien ämnat till att studera den nuvarande reservdelsförsörjningsprocessen, att effektivisera reservdelsförsörjningsprocessen och att utreda vilka utmaningar som kan uppstå vid en förändring av denna samt hur dessa ska kunna hanteras för ett effektivt förändringsarbete.
Vattenkvalitén i Fredstorpsbäcken - dikad bäck på fastigheten Rämningstorp i Skara kommun :
The estate of Rämningstorp in the region of Västergötland in southern Sweden is administered by the holding trust company Skogssällskapet i Skövde. In 1999 measures were taken by Skogssällskapet to drain the stream Fredstorpsbäcken as a means to increase the forest productivity of the surrounding lands, which are situated on the estate of Rämningstorp. Almost immediately after the drainage, the streamwater turned turbid and a landowner downstream reported the issue to the county administrative board of the region.
The aim of this thesis was firstly to analyse the suspended matter that appeared during summer/autumn and secondly to explain why it came to be. Initial hypotheses for the explanation to the greyish turbid water were that it was either 1) a chemical/biochemical precipitate, or 2) an bacterial/algal blooming.
Motivation for eating roughage in sows : as an indiction of hunger
Today?s feeding methods can determine the domestic pig?s abilities to fulfill basic behavioral needs, such as foraging, and the way in which pigs are feed is an important aspect. Feed does not only provide the energy and nutrients critical for survival, but feeding is also associated with a number of other factors contributing to well-being and reproduction. Today the feed for gestated sows is often composed by high energy and low dietary fiber grain products such as wheat. Three kg of this kind of feed can often be consumed by the sow within 20 minutes.
Utredning av pallsprängning med lutande borrhål i Aitik
Examensarbetet har utförts vid Boliden Mineral AB dagbrott i Aitik under perioden 2011-03-28 till 2011-06-01. Syftet med examensarbetet var att göra en utvärdering av pallsprängning lutande borrhål för att se om fragmenteringen förbättrades. Dessutom studera andra effekter som påverkas av fragmentering, t.ex. antal icke hanterbara block (stenar större än 1m3), flöde i primär krossanläggning och grävbarhet. Studien genomfördes genom att en försökssalva sprängdes, där en del av borrhålen var vertikala och den andra delen bestod av lutande borrhål.