Sökresultat:
1582 Uppsatser om Soil water - Sida 3 av 106
Kan markfuktighetskartor användas för att hitta skogsmark med hög bonitet? : ett gis-baserat försök med dtw-index och laserskannad övre höjd
The depth-to-water-index (DTW-index) is derived from digital elevation models (DEM) to map soil wetness, in terms of distance from soil surface to the ground water table. The aim of this GIS based study was to investigate the existence of a relationship between DTW-index and forest site productivity (SP). The belief of such an assumed relationship was based on knowledge that the ground water level is related to site properties that can either promote or impede tree growth.
Data primarily comprised rasters of the Krycklan catchment in northern Sweden and depicted DTW-index and a laser scanned vegetation height. The 100th height percentile of each pixel in the vegetation raster was assumed to mirror the top-height, letting it act as a relative measure of SP within a delineated area of equal stand age.
Koldioxidavgång vid ekologisk odling på organogen jord
The background of this work is the media discussion about the effect of cultivation on peatsoils on greenhouse gas emissions. It has been argued that row sown and intensivelycultivated crops such as carrots are more likely to emit carbon dioxide than for example grassleys. The association KRAV (an association promoting organic farming) shall, from this yearadapt their environmental policy to be more climate smart and have asked the question if thecultivation of some crops is more climate smart than others? Carbon dioxide emissions fromsoil are due to degradation of organic material and the rate is controlled by microbial activity.The microbial activity is determined by a variety of factors such as temperature, soil organicmatter quality and water content. I have measured the carbon dioxide emission from fourdifferent crops at two different farms.
Den bäcknära zonen vid små skogliga vattendrag i Värmland : generell beskrivning, förekomst av traktorspår samt kvicksilverhalter i körpåverkat ytvatten
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.
Water balance and nitrate leaching from arable land in a changed climate : a model study
This thesis aims to present the essential background on how to perform climate changeimpact assessments, and to present the results from a climate impact assessment on waterbalance and nitrate leaching for an arable Swedish soil. The soil is a sandy soil in southwesternSweden, grown with spring cereals. This study is meant to be a benchmark example,and cannot be seen as a regional or national assessment for Sweden, rather as an approachto present and analyze the most important parts of these kinds of assessments.A dynamical simulation model (COUP, Jansson and Karlberg, 2004) was used for thisstudy. The model was parameterized and calibrated against data from an experimental site,located in Mellby in Hallands county, south western Sweden. Measurements were carriedout between 1st of April 1988 and 1st of April 1991.
VäxtVäktare
Most people have been forced to throw away a pot-plant after its death. There are many reasons to the death of a plant, but mainly it?s because its owner forgets it, and therefore fails to water it.
The purpose of this project is therefore to develop a product which can prevent this from happening, while the product has to have a low manufacturing cost to be able to compete whit other, similar, products on the market.
During the project, a benchmarking has been done to give a clear picture of what the product has to compete with. The directives there are for CE-marking, and which of these who concerns the product has also been looked up.
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.
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.
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.
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.
Vattenbehov och olika system för vattentilldelning till nyavvanda grisar :
We all know that water is very important for both animals and humans. When we are
weaning the piglets from the sow we must guarantee that the piglets can start to drink
more water instead of sow milk. The first thing to check is always the quality of the
water that is to be used. To secure that, you must take a water sample. If the water is
inadequate it can bring a lot of problems and diseases.
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.
Concentration and offtake of trace elements and macronutrients in Italian ryegrass (Lolium multiflorum Lam.) and spring barley (Hordeum vulgare L.) grown on soils amended with water treatment residual sludge
Aluminium sulphate (Al2(SO4)3) is usually added during the drinking water treatment processin order to precipitate organic and inorganic material, resulting in aluminium-based drinkingwater treatment residual sludge (WTR). Since 2003 Swedish law no longer permits WTR tobe deposited in lakes, and there is an interest to explore the possibility to utilize WTR as soilamendment. The aim of this study was to examine the effects of WTR application on cropgrowth and concentrations of macronutrients and trace elements (including micronutrients andpotential toxic elements). A greenhouse pot experiment was conducted with three soils; a clayloam rich in phosphorous (P), a loamy sand rich in P, and a silty loam with a low soil Pconcentration, and two crop species Italian ryegrass (Lolium multiflorum Lam. cv.
Översyn av vattenskyddsföreskrifter med tillhörande vattenskyddsområde i Hallstahammars kommun. : Vilka revideringsbehov finns?
Water is an important food and an important natural resource. In order to protect these are the Environmental Code and the EU directive given to water protection and related water protection regulations will be established for all water sources until 2010. Those who will prepare a water protection and related water protection regulations is the municipality or person responsible for water supply. The person then decides and declares the area as water protection and related water protection regulations are municipal or provincial government. The idea of creating a water protection is to protect the water supply and the body of water against pollution caused by point sources, diffuse sources and accidents combined.
Är Lerbodaälven verkligen en problemälv? : undersökning av fosforhalter
Lerbodaälven is a river in the municipality of Kil which, due to high phosphorus content is not meeting the requirements for good ecological status according to the Water Framework Directive. The purpose of this report is to investigate the causes for the high content of phosphorus that has been measured in Lerbodaälven between 1995-2010. Four questions will be answered in this report.
1. Does the sewage treatment work affect the phosphorus level in Lerbodaälven?
The result from the time series analysis shows that the sewage treatment works have a small impact on the phosphorus level in Lerbodaälven.
Uttorkning av lera : Orsaker och följder
When building a house or similar the stress on the ground increases and deformations can arise. The deformations create a foundation that the building is not constructed for and damages on the building arise. The increased stress on the ground can be derived back to the building, but it is possible that the increased stress may well derive from different sources such as other buildings or trees. The building is an older property, built in the late 19th century alternatively early 20th century, and is today used for rental housing and has suffered severe damages due to subsidence. The goal of the thesis is to find possible causes for these subsidences. The thesis was executed as a combination between literature- and casestudie. After careful studies it has been found that a probable cause for these subsidences is trees. Through field- and lab studies it has been found that the trees has effected the ground through there accumulation of water.