Sök:

Sökresultat:

4047 Uppsatser om Soil water content - Sida 1 av 270

Aggregatstabilitet, jordbearbetning och fosforförluster i ett typområde på jordbruksmark :

Large amounts of phosphorus (P) are lost from the arable land due to water erosion. Both phosphorus attached to particles and dissolved phosphorus (mainly phosphate) are transported away with drainage-water and surface runoff. Good soil structure is important in minimizing these losses. In this study, soils from 50 fields were analysed with respect to aggregate stability as measured by dispersion of clay together with the content of total phosphorus (TotP), particulate phosphorus (PP) and phosphate phosphorus (PO4P) in the water phase. All soils were clay soils with clay content varying between 21 and 54%.

Autumn water sources for understory vegetation and fungi in a boreal forest : an evaluation using stable isotopes

Understory vegetation and fungi are regarded as important ecological drivers of processes like productivity and nutrient cycling in boreal forests. Whilst those processes are linked to Soil water content, relatively little is known about the sources of soil water for these forest components. During early autumn in boreal forests, temperature falls and large events of rain are frequent which may influence soil water availability. To better understand the autumn plant-soil-fungi water relationships in this ecosystem, I used stable isotopes techniques in this study to examine the water sources for ericaceous shrubs and fungi in a Scots pine forest following a large, early autumn rain event. I hypothesize that ericaceous shrubs of two functional groups (evergreen vs.

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.

Källor i Lagga, en uppländsk slättbygd : Geografisk och geologisk påverkan påkällvattens egenskaper

For centuries, springs have played a significant role in our society as water supplies, reasons for where to settle down, and in folklore. There are different reasons why and where a spring forms, e.g. in what kind of soil it has its outflow. Geographic and geochemical surroundings have an influence on spring-water quality.For this project some of the springs in the Lagga perish, Knivsta municipality, Sweden, were selected for a closer study. Water samples were collected from springs for analysis.

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.

Sjuksköterskors erfarenhet av att vårda patienter med självskadebeteende

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.

Hur mycket "mjölk" ska det vara i mjölken, och hur styr vi det?

In most countries, the dairy industry focuses on the volume of milk produced instead of its composition. This results in a high content of water and a lower proportion of fat and protein. A high proportion of water is not desirable when processing the milk into various dairy products like cheese, cream and milk powder. High water content also increases the costs for transport and storage, and also an unnecessary, albeit marginal, strains on the world?s water reservoir.

Järnets förekomst i grundvattnet i isälvsavlagringar i Dalarna : Bakgrundshalter och rörmaterialets inverkan vid grundvattenprovtagning

A study has been performed that investigates the variation of iron content in groundwater.The study was initiated by Midvatten AB, which noticed that the iron content in groundwater samples can vary greatly over small distances. The purpose of this study was to geochemically and geohydrologically determine the factors that influence the content of iron and manganese in groundwater from a selection of eskers in Dalarna, and determine how to best sample groundwater with the method used by Midvatten AB. An evaluation was made of how the vertical variation in soil material, water composition, pumping time and pipe material affects the content of iron in groundwater. Piper diagrams were used to study the relationship between the chemical composition of the groundwater and the content of iron and manganese in groundwater samples from the studied areas. The groundwater from the studied areas was then classified in the Piper diagrams, according to the content of the major ions.

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.

Anva?ndning av markfuktighetskartor fo?r sta?ndortsanpassad plantering

Digital depth-to-water maps can be produced from a digital elevation model (DEM). Then GIS- based algorithms are used to calculate water flows and the depth-to-water index classes dry, fresh, moist and wet. The purpose of this study was to investigate the possibility to use depth- to-water maps for site adapted planting.The results showed that use of depth-to-water maps for site adapted planting, roughly halved the proportion of improperly planted surfaces from an average of 9 % to 4 %. The variation in the values of proper surface decreased and the result became more even.. In addition, more pine than spruce was incorrectly planted.

Djup icke vändande bearbetning i sockerbetsodling :

A field experiment was carried out in 2006 to investigate the effects of deep rotary cultivation on sugarbeet growth. The background to the experiment was a 2005 study showing potentially higher yield, higher cleanness and higher sugar content when primary tillage was carried out to 35 cm depth with a rotary cultivator. On four field sites in Skåne (L:a Isie, Ädelholm, Stävie and Vragerup), five different treatments were compared: mouldboard ploughing in the autumn to 20 cm; mouldboard ploughing in the autumn to 20 cm + rotary cultivation in the spring to 35 cm; rotary cultivation in the autumn to 35 cm; rotary cultivation in the spring to 35 cm; and mouldboard ploughing in the spring to 20 cm. The rotary cultivator used in the treatments is manufactured by a Dutch company, Imants. The implement cultivates the soil with spade tines fitted on arms that are mounted on a horizontal rotating PTO-driven axle. Beet plants were inspected and yield determined in the experiment, and three soil parameters were examined: penetration resistance, water infiltration and infiltration of blue dye. Root shape was also examined. The site at Stävie was not harvested due to poor beet establishment. At the other sites, the highest yield was found when the soil was rotary-cultivated in the autumn.

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.

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.

Irrigation scheduling for efficient water use in dry climates

In this report the importance of irrigation scheduling in dry climate is shown, how it can save water and energy; how this method can improve crop yield by supplying the right amount of water at the right time. It is shown how irrigation scheduling and irri-gation technology together increase the irrigation efficiency..

Variationer av klor, svavel och aska i havrekärna : odlingsfaktorernas inverkan på havrens bränsleegenskaper

The increasing oil prices during the last years have made it profitable to use cereal grains as a fuel. When compared with wood, cereals contain higher amounts of Cl, S and ash. The Cl and S content makes the gases from cereal combustion more corrosive than gases from wood combustion. The goal of this master thesis was to find out the variation of Cl, S and ash content for oat grain grown under different conditions. Oats was chosen because in Sweden it's considered as the cereal with the best fuel qualities.

1 Nästa sida ->