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1020 Uppsatser om Soil parameters - Sida 2 av 68
JB-TOTALSONDERING : Jämförande sonderingar och utvärdering av egenskaper i isälvsavlagringar kring Igelstaviken
The main purpose of this thesis has been to find a way to evaluate the Soil parameters for the Total sounding method (TS), such as the inner friction angles and settlement modules. This study only includes an analysis of soil profiles from the Stockholm region. The chosen location for the study is a proposed residential area east of Igelstaviken in Södertälje. Presently, the subject plot is located in a residential area and is also adjacent to a school area.Total sounding is originally a Norwegian soil testing method. The differences between the sounding methods (weight-, ram-, CPT-sounding) are for instance how the sound is driven into the ground and what kind of parameters that are registered.
Allanblackia stuhlmannii ? a tree under current domestication: what are the soil requirements?
Allanblackia is a genus of trees that grows in the rainforests of West, Central and Eastern Africa. Its big fruits contain seeds very rich in oil which has been used by
local communities for cooking and making soaps. The native stands are threatened by overexploitation and the demand for the oil is much greater than the supply.
Domestication programs, aiming at introducing the trees to small holder agroforestry systems, have been started for some of the species. The main aim of this study was to investigate the soil requirements of Allanblackia
stuhlmannii in terms of chemical and physical parameters, as revealed by the soil conditions in native stands. Another aim was to see if these varied along an altitudinal transect.
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.
Identifiering av synkronmaskinsmodell genom SSFR-test
At the Division of Electricity at Uppsala University there is an experimental rig forhydroelectric generators. The experimental rig?s vital part is a 12-pole synchronousmachine, whose electrical characterizing parameters (resistances, inductances andtime constants) are unknown. The aim of this thesis is to characterize the machine inits current state by perform a Standstill Frequency Response (SSFR) test. From theanalysis of the measurement data, which is a part of the test, a set of basic parametershave been received.
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.
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.
Utveckling av en HBV/PULS-model med sammanfogade markfuktighets- och responsrutiner
Soil properties affect the chemical composition of soil water. When studying transport of chemical substances through a basin, it is therefore important to know from which soil layer the main part of the runoff is generated. The aim of this study is to develop an HBV/PULSE model with merged soil moisture and response routines, which generates good approximations of groundwater levels. It should be possible to extend the model to simulate transport of substances and take into account which soil layer the groundwater level is currently in. The hydrological version of HBV/PULSE is used since there is no need to account for pH or alcalinity at this stage.
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.
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..
Bärförmågetillväxt i pålad friktionsjord
Piled friction soil show a set-up which is increasing with the time after installation. The cost could be reduced if the set-up had been taken into account when designing but in Sweden it is very unusual to do that. Previous studies showed that set-up can vary between 25 % and 75 % during the first 90 days after pile installation. This showed that the effect of the phenomenon is difficult to predict. A study involving five projects have been carried out by specifying certain parameters like pile type, method for pile installation and test method for measure the bearing capacity in friction soils located in Sweden.
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.
Effekter av bearbetningsdjup i plöjningsfri odling
In Sweden, reduced tillage usually means non-inversion tillage, where primary tillage is carried out using chisel ploughs or disc implements. Primary tillage method is mainly determined by the desired soil loosening and the handling of soil residues.
The effect of tillage depth was studied in field experiments in Skåne, Väderstad, Uppsala, Örebro och Västerås in different crops; spring oilseed rape, spring wheat, winter wheat and spring barley.The experiments generally had a randomized block design with the treatments mouldboard ploughing, deep chisel ploughing and shallow chisel ploughing, in some cases also shallow discing and no-tillage. In the experiments the following parameters were determined: seedbed properties, saturated hydraulic conductivity, penetration resistance, number of emerged plants and crop yield (all parameters were not determined in all experiments. Root growth and draught requirement were determined in two separate studies.
There were no significant differences between tillage depths in non-inversion tillage in seedbed properties, plant emergence or root development.
Däck-mark Interaktion hos skogsmaskiner
The most predominant method for forest harvesting in Sweden is the cut-to-length method based on two-machines, a harvester that fells trees and cut them in a predefined length, and a forwarder which transports logs to a landing area for further transport to a processing facility. New machine solutions have to be much gentler to the ground than today?s machines. To be able to develop a forestry machine that preserves the terrain requires a proper understanding of the interaction between tire and soil.The goal of the project is to contribute to the existing knowledge of forest machine tire-soil interaction and to develop a tire-soil model that enables dynamic simulations of forest machines operating in rough terrain. The modeling has especially been focused on the interaction between tires and soft ground.A comparison of theoretical data of different WES-based terrain interaction models and a comparison test data from a full scale field test is presented.
Migration och vegetationsupptag av radiocesium i åkermark - en långtidsserie av mätdata samt en långsiktig simuleringsmodell :
Abstract
The accident in 1986 at the nuclear power station in Chernobyl, Ukraine, dispersed radioactive cesium over large areas of Europe. The half life of 137Cs is 30 years and this radionuclide also behaves like potassium, which means that it can easily be taken up by the vegetation or be adsorbed in to the structure of clays, principally illitic clays. When radiocesium decays ionizing radiation is emitted, which is harmful to humans that are exposed, either directly or indirectly through food intake. It is there-fore important to know what happens to the cesium that is dispersed into the environ-ment.
In this project a simulation model was constructed to simulate the adsorption and transport of radiocesium in the soil and plant uptake.