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4047 Uppsatser om Soil water content - Sida 6 av 270
Effects of biogas residues on respiration and denitrification in arable soil : evaluation of methods, microbial activity and agronomic implications
Agricultural soils constitute the base in human food production and soil content of organic matter and plant nutrients together with soil microbial activity are all important parameters for high crop yield of good quality. These parameters are dependant on proper fertilization.Anaerobic digestion of organic wastes for biogas production generates a liquid residue called biogas residue (BR). It contains organic material and plant nutrients which makes ita potential fertilizer for arable cropping. However, it also contains heavy metals and toxic organic compounds and it is therefore in need of evaluation before usage.Microbial tests were performed aiming to evaluate the agronomic traits of four different BR and to find a viable procedure for evaluating slurry fertilizers. Two experiments where soil respiration and soil potential denitrification activity (PDA) was measured at fertilizer addition were performed.
Torrfoder till katt : påverkan och konsekvenser
The cat has evolutionary become an obligate carnivore. Today it is common to feed the cat a dry food. Studies have shown that the dry formula can have negative consequences for the cat. A literature study where conducted to investigate whether the cats origin makes it incapable to compensate for the changes a dry food entails. The impact and implications regarding water intake, energy intake and blood glucose concentration when feeding the cat dry food where examined.
Sänkta sjöars inverkan på ytvatten i Västerbottens kustland : Samband mellan sänkningsnivåer och vattenkemi i sjöar på sulfidrika sedimentjordar
Lake lowering in sulphide-rich areas is currently a major environmental impact for surface water. This study focuses on whether there is a relationship between a gradient of lake lowering and surface water impacts in areas of sulphide-rich sediments, in order to better understand their contribution of heavy metals and sulfuric acid. Also, is it a reasonable method to use the reduced lake area in order to quantify the gradient? The survey was conducted by collecting water samples from reference lakes and lowered lakes from south to north in coastal areas within the county of Västerbotten. Water samples were then analyzed for TOC, pH, conductivity, anions, base cations, alkalinity, acidity, sulfate, Al, Cd, Fe, Mn, Cu, Zn and Pb.
Markskadefri avverkning - från traktplanering till plantering
This study is made for Södra skog and is concerning how to minimize soil damage from planning to plantation. The purpose of the study is from the respondent?s perspectives; their own ideas and approaches.
What emerged from the interviews is that the communication between the different organization levels can be improved.
It is also important to prevent damage on the soil and to have in mind that the process of planning tracks to plantation continues for a long time and because of that, the soil condition meanwhile will change..
Gestaltningsförslag för Norbyvreten : från kvarterspark till stadsdelspark
The prevailing food and energy crisis of the world, due to the declining reserves of fossil energy and a never ending rise of consumption, forces us to look into new fields to supply our energy demand. The boom of bio energy is criticized, as food crops are used to provide biodiesel and ethanol and the volumes are ridiculously small to supply world demand. Algae are one of the world?s oldest life forms and exist in many different phyla, providing a great variety to choose from, for different purposes. Cultivating microalgae offer a way to produce energy at great volumes without competing with food production and at the same time the algae offer a way to use our expensive nutrients in a more efficient way, besides this the algae are carbon dioxide neutral since their carbon source can be supplied by the atmosphere and the additional energy required can be supplied by algal oil or other renewable sources.
Långsiktig förändring av fosforhalt och skördenivåer för jordar med höga P-AL-tal : en analys av försöksserien "Exploatering av höga fosfortillstånd"
The field trial Exploatering av höga P-AL-tal (Exploiting P in heavily P dressed soils) started in 1982-1983 and included seventeen study sites placed across Sweden.
Each site included three treatments, one unfertilized control (A), one aiming at replenishment of harvest removal, i.e. fertilized with 15 kg P ha-1 year-1 (B) and one over-fertilized (C) with 30 kg P ha-1 year-1. In this thesis data from the five longestrunning study sites are analysed based on four hypotheses. The hypotheses stated
that in soils with high P-AL values and a pH over 6.0 P-AL will not decrease over time in the control (A) or in the replenishment treatment (B), that P-AL and P-HCl
in the top soil will increase at all sites for the over-fertilized treatment (C) and that yields will not decrease as long as the P-AL is above 12 mg P 100 g-1 soil.
My conclusions from the analysis of data from the selected sites are as follows:
- A pH above 6.0 cannot guarantee a stable P-AL value in an unfertilized
but phosphorus-rich soil.
- The P-AL of unfertilized soils decreased faster at lower soil pH than at
higher pH.
- In the replenishment treatment (B) the rate of P-AL decrease seems to fall
at a pH of 6.5. However, the influence of the soil type cannot be ignored.
- P-AL and P-HCl did not increase in all over-fertilized treatments.
Vinster med björkinblandning i granbestånd i syfte att höja markens pH-värde
The soil acidification and the pH-value of the soil have been discussed for many years. Many observations of the tree species effects on the soil pH have been done.
We have discussed the effects on the soil surface pH-value with a birch (Betula spp. L.) admixture in Norway spruce stands (Picea abies L.).We have used data from the Swedish National Forest Inventory. We have also discussed how the wood production and the biodiversity can be increased in mixed stands, in according to the Swedish forestry act Skogsvårdslagen. Our sampling areas are located in Norrland, Sweden.
The results show a significant correlation between an increased birch admixture and an increased pH-value of the soil.
Kväveomsättning i gräsmark med olika artantal och artsammansättningar :
This study was carried out at the Swedish University of Agricultural Sciences, Dept. of
Agricultural Research for Northern Sweden. The aim of the study was to determine how plant species richness and diversity influence the nitrogen pools and nitrogen fluxes in the soil. Plant and soil samples from a biodiversity experiment in grasslands were used. Thirty plots with 12 grassland plant species (legumes, grasses, and non-legume herbs), combined from 1-12 species were investigated.
Vallbrott med hjälp av grisar :
To investigate the possibilities for effective soil tillage, that could imply lower costs,
lower negative environmental impact and in addition a meaningful occupation for foraging pigs, a field experiment was carried out in Gränna, Småland, during growing season 2006.
The experiment contained two treatments that were repeated three times and were carried
out on a couch grass-infected fallow on a light soil close to Sweden?s second largest lake, Vättern. Ploughing was one treatment and pig rooting followed by ploughing, was the
other. The experiment was conducted according to the guidelines of organic growing and
seedbed preparation was done the same way in the two treatments. The pigs, three groups
of five half-year old Linderödssvin (an old Swedish breed), was encouraged to perform
an even tillage by strip-grazing, i.e.
The bioavailability of soluble oxalates in stir-fried silver beet leaves
The prevailing food and energy crisis of the world, due to the declining reserves of fossil energy and a never ending rise of consumption, forces us to look into new fields to supply our energy demand. The boom of bio energy is criticized, as food crops are used to provide biodiesel and ethanol and the volumes are ridiculously small to supply world demand. Algae are one of the world?s oldest life forms and exist in many different phyla, providing a great variety to choose from, for different purposes. Cultivating microalgae offer a way to produce energy at great volumes without competing with food production and at the same time the algae offer a way to use our expensive nutrients in a more efficient way, besides this the algae are carbon dioxide neutral since their carbon source can be supplied by the atmosphere and the additional energy required can be supplied by algal oil or other renewable sources.
Vattenhaltmätning i konfektyr och sylt med Karl Fishermetoden
Abstract (in English)The task for the diploma work was to develop methods for measuring of moisture content by the Karl Fischer method, in jam, jelly sweets, and fudge.The start premises was a for the company whole new equipment, which should be started up. Then programs should be developed for different kind of samples.In the task it was as well included to develop methods for dissolving the different kind of samples, since the Karl Fischer method demands completely dissolved sample material..
?R KUSTN?RA ALK?RR I BOHUSL?N ETT ?BLUE CARBON? HABITAT?
In coastal wetlands carbon/organic matter can be stored for long periods of time thanks to, among other things, the presence of water which slows down the decomposition. Because of this, restauration and management of such habitats have the potential to decrease the emission of greenhouse gasses and help mitigate climate. Internationally these environments are called ?blue carbon? ecosystems. In Sweden, alder (Alnus glutinosa and Alnus incanata) covered wetlands along the coast is a nature type that potentially could function as a ?blue carbon? habitat.
Vattenskydd och krisberedskap hos allmän dricksvattenproduktion : Skydd av täkter, tillgång till reservvattentäkter och andra nödvattenlösningar hos svenska vattenproducenter
The objective of this report was to analyse and compare vulnerability and preparation in Swedish municipal drinking water production, in case the commonly used water sources were inoperative. Methods used were a questionnaire and a less extensive study of regulations for water protection areas. The questionnaire was answered by 41 Swedish municipalities. A handful of them were companies co-owned by a few municipalities. Only one out of four municipalities had source protection areas to all their water sources and for many sources the protection was not satisfactory.
Hyllie vattenpark : ett gestaltningsförslag
This project is focusing on a future park that will surround Hyllie water
tower in the outskirts of Malmö. The water tower will be located in the
central part of the new building area Hyllievång. The park will function
as a town park with a special focus on water. The water council of the
municipality, Va-verket, has for the last 7 years built up and been in
charge for a pedagogical programme in the water tower, were schoolchildren
come to learn about the cycle of water and how we use water
in our daily life. In the park they want to build a new part that gives
experience of water, as a compliment to the information in the tower.
What will that park look like, and what shall it be constructed of?
How do you bring water to the surface in a park? How can landscape
architecture work to enhance the presence of water and make people
more interested in water issues? In the search to find the answers to all
my questions I have meet with people, read books and visited different
places.
Spridning av släckvattenpartiklar : En studie på spridning av partiklar genererade från brand
During a fire large amounts of particles and unhealthy agents occur. Polyaromatic hydrocarbons (PAH) and toxic metals are examples among many others. These agents have a capacity to bond to particles and when the fire is extinguished, the particles can be transferred with the extinguish water into the soil and to the groundwater.Recent studies in particles have been conducted. A study by Ulrika Iverfelt (2014) reviled that the particles from a fire contained large amounts of both PAH and metals, which is consistent with earlier analyses. Her column experiments with particles in the size ? 11 microns and ?100 microns in silica sand, reviled that the larger particles was immobilized because the transportation was influenced by sieving or physiochemical particle and surface interactions.The transport of the particles in soil and groundwater is regulated by two main mechanisms: physiochemical surface interactions and straining.