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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Near-natural forests in southern Sweden : silvicultural and palaeoecological aspects on nature-based silviculture /

Björse, Gisela, January 1900 (has links) (PDF)
Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniv. / Härtill 5 uppsatser.
2

Effects of site preparation on soil properties and on growth, damage and nitrogen uptake in planted seedlings /

Nordborg, Fredrik, January 1900 (has links) (PDF)
Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniv., 2001. / Härtill 5 uppsatser.
3

Högläggning eller harvning : En jämförande studie av planteringspunkter och markpåverkan vid olika terrängförhållanden. / Mounding or disc trenching? : A comparing study of planting spots and terrain impact in different types of terrain.

Karlsson, Josef January 2016 (has links)
A comparing study of planting spots and terrain impact in different types of terrain.
4

Managing reindeer lichen during forest regeneration procedures linking Sami herders' knowledge and forestry /

Roturier, Samuel, January 2009 (has links) (PDF)
Diss. (sammanfattning) Umeå : Sveriges lantbruksuniversitet, 2009. / Härtill 5 uppsatser.
5

Hur påverkas markberedningsresultatet vid harvning och högläggning av faktorer som lutning, ytstruktur och markfuktighet?

Wikner, Frida January 2015 (has links)
Soil scarification means lot to the regeneration of the forest because a good soil scarification boost the increment of the plants and it also makes the plants less attractive to dangerous insects. The surveys purpose was to investigate how different site factors influence the soil scarifications results. The goal was to see if any scarification method was better adapted to a certain site then the other. In order to see a result the survey investigated the bearing capacity of the stands, the surface structure and the slope of the terrain. The surveys material has been collected during august - October 2013 on SCA: s forest in Ångermanland in Sweden. Totally has 65 harrowed sites and 35 scalped sites been visited and material collected from. The survey result shows that the scarification quality after scalping was higher than after harrowed sites. The number of 5: s and 4: s was more frequent after scalping but the number of mineral 3: s was higher after harrowing. The analysis of the results shows that scalping was more sensitive to the site slope and surface structure then harrowed sites, but when used on the the right ground it will provide a better quality result. The conclusion of the survey was that harrowing is the better choice of the scarification methods because it showed a more stable result then scalping that is more depending on the terrain conditions. Harrowing should not be used on moist ground due to the risk of Hylobius abietis attacking the plants. Scalping on the other hand showed a better result of the scarification quality and on the right ground it is the optimal choice.
6

The effect of scarification, temperature and light conditions on seed germination of Artemisia afra jacq. Ex willd.

Letsoalo, Mmakoma Mendy January 2022 (has links)
Thesis (M.A. Agricultural Management (Plant Production)) -- University of Limpopo, 2022 / Artemisia afra Jacq. ex Willd is a common medicinal plant in Africa belonging to the Asteraceae plant family. It has been used for decades as a treatment for cold related illnesses and a variety of other ailments such as asthma, malaria and kidney disorders. As such this has led to its high demand and it is faced with threats of overharvesting. As the plant is naturally occurring and not widely cultivated, it’s seed biology and germination properties are not documented. The optimum requirements (temperature and photoperiod) for seed germination as well as the effects of Moringa based biostimulant and different scarification methods were investigated on A. afra seeds in this study. The seeds were exposed to different scarification methods including physical scarification (rubbing using sandpaper), hot water soaking, cold water soaking, acid treatment (H2SO4) and fermentation (using effective microorganisms) while the untreated seeds served as the control under all conditions. Moringa based biostimulant was also used as a seed priming agent at 0, 0.5, 1 and 3% levels. The seeds were then placed under a variety of photoperiods including constant light, alternating light (16/8 hours) and continuous darkness at different temperatures (15°C, 25°C and 35°C). Germination percentages and mean germination time (MGT) were calculated from the results and Statistix 10.0 software was used at the probability level of 5%, to compare the mean values. It was observed that under the different temperatures without any other treatments, the highest germination rate (70%) was achieved at a 25°C. No germination (0%) was obtained at both 15°C and 35°C in all the experiments including scarification methods and photoperiods. Under the scarification treatments, soaking in hot and cold water scarification improved germination with final germination of 70%, compared to the other scarification methods (Physical at 20%, acid treatment at 20% and control at 10%). There was no germination observed (0%) for the fermented seeds in all the experiments. On the photoperiod treatments, the highest germination percentage of 70% was observed under alternating light condition. However, when mean germination time was calculated, continuous xiv darkness resulted in shortest MGT of 11 days compared to 13 days for both alternating light and for continuous light in this set of experiment. Seed priming with Moringa based biostimulant under alternating light conditions and at 25°C resulted in improved MGT. Under the investigated treatments, the use of 3% biostimulant exerted the highest improvement on germination with germination percentage of 62% and the shortest MGT of 7 days compared to the other treatments. Generally the final germination (%) and time of A. afra seeds were affected by scarification, temperature, light and priming using Moringa based biostimulant. The information generated from this study is important because it will contribute in bridging the scientific gap on the information that has never been documented on optimum requirements for effective propagation of A. afra through seeds. As such this information will be useful for small scale farmers and medicinal plant growers who are willing to recover the lost populations of A. afra through seed propagation thus improving their supply and income / National Research Foundation (NRF)
7

Paprastosios pušies (Pinus sylvestris L.) žėlimui įtaką darantys aplinkos veiksniai / The environmental factors influence on scots pine (Pinus sylvestris l.) natural regeneration

Bačkaitis, Julius 09 June 2005 (has links)
The aim of this study is to investigate the possibilities of pine natural regeneration in different nature regions in the clear-cuts with main site types. The tasks of this work are: 1. to estimate a potential possibilities of pinewood natural regeneration; 2. to find out the ecological factors, that have a great influence on pine sprouts on the Na (dry not fertile), Nb (dry less than average fertile) and Lb (with excess water and less than average fertile) site types and to set their critical borders; 3. to find out the main economical factors, that promotes pine regeneration (site preparation, seed trees, shelter wood); 4. to prepare the recommendations to promote the pinewood natural regeneration. Recency and originality. This is the first investigations were made in complexly including the most common sites in Lithuania for pinewood (Na, Nb and Lb site types) in the three native regions covering largest part of Lithuania. This enables to make prognoses of pinewood regeneration in those regions on the mentioned site index. For the first time there were defined the sufficiency of the shelter-seed trees for regeneration and their distribution in a clear and step wise cutted areas to ensure the natural regeneration of pine. There were found that 2-3 point yield of pine seeds (under Capper) and on the time and in right way implemented encouragements, ensure natural pine regeneration after clear or step wise cuttings. Following the results, it was suggested to advance the... [to full text]
8

Base-cations in relation to weathering of phyllosilicates and forest management in Swedish forest ecosystems /

El Make, Mahmoud, January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2000. / Härtill 4 uppsatser.
9

Geoestatística e análise múltipla de atributos químicos de um latossolo cultivado com soja sob dois sistemas de manejo /

Silva, Paulo Ricardo Teodoro da. January 2017 (has links)
Orientador: Rafael Montanari / Resumo: No cerrado brasileiro o Sistema Plantio Direto tem sido adotado expressivamente por agricultores. Contudo, o tráfego de máquinas e implementos em condições de alto teor de água no solo e as sucessivas adubações superficiais, tem provocado problemas de compactação e acúmulo de nutrientes na superfície, o que pode levar ao aumento da variabilidade espacial de nutrientes e na baixa expressão do potencial produtivo das culturas. Com a escarificação do solo, como prática para aliviar a compactação do solo, pode haver alterações na variabilidade horizontal de nutrientes devido à mobilização parcial do solo. Desta forma, a pesquisa teve como objetivo avaliar a variabilidade espacial dos atributos químicos do solo proporcionada pela escarificação do solo em Sistema Plantio Direto, e identificar por técnicas multivariadas, os principais atributos químicos do solo que melhor se relacionam com os componentes de produção e produtividade da soja. O experimento foi realizado num LATOSSOLO VERMELHO Distrófico, no ano agrícola 2015/16, na Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia - UNESP, Câmpus de Ilha Solteira, localizada no município de Selvíria - MS. O experimento consistiu-se em duas áreas de cultivo, uma sob Sistema Plantio Direto (SPD) implantado há 13 anos e outra em Cultivo Mínimo escarificado (CM). Para coleta dos dados, foram alocadas duas malhas geoestatísticas, uma em cada área de cultivo. Cada malha foi constituída de 51 pontos equidistantes com uma dist... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In the Brazilian cerrado the no-tillage system has been adopted expressively by farmers. However, the traffic of machines and implements in conditions of high water content in the soil and successive superficial fertilizations has caused problems of compaction and accumulation of nutrients on the surface, which can lead to increased spatial variability of nutrients and low expression potential of crops. With soil scarification, as a practice to alleviate soil compaction, there may be changes in the horizontal variability of nutrients due to partial soil mobilization. The objective of this research was to evaluate the spatial variability of soil chemical attributes provided by soil scarification in no - tillage system, and to identify by multivariate techniques, the main soil chemical attributes that best relate to soybean yield and productivity components. The experiment was carried out in a dystrophic Oxisol, in the agricultural year 2015/16, in the Experimental Farm belonging to the Faculty of Engineering - UNESP (Ilha Solteira), located in Selvíria - MS. The experiment consisted of two cultivation areas, one under no-tillage system (NT) implanted 13 years ago and another in minimal cultivation scarified (MCS). To collect the data, two geostatistical meshes were allocated, one in each cultivation area. Each mesh was made up of 51 equidistant points with a distance between points of 10 m. The final population of plants, the height of insertion of the first pod, the height of... (Complete abstract click electronic access below) / Mestre
10

Geoestatística e análise múltipla de atributos químicos de um latossolo cultivado com soja sob dois sistemas de manejo / Geostatistics and multiple analysis of chemical attributes of a oxisol grown under soybean under management systems

Silva, Paulo Ricardo Teodoro da [UNESP] 17 August 2017 (has links)
Submitted by Paulo Ricardo Teodoro da Silva null (paulo82239@aluno.feis.unesp.br) on 2017-10-10T02:41:22Z No. of bitstreams: 1 Paulo Ricardo Teodoro da Silva_final.pdf: 5656626 bytes, checksum: 2c9618d4f90a4b6da73ade7a307dadcd (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-10-11T15:02:10Z (GMT) No. of bitstreams: 1 silva_prt_me_ilha.pdf: 5656626 bytes, checksum: 2c9618d4f90a4b6da73ade7a307dadcd (MD5) / Made available in DSpace on 2017-10-11T15:02:10Z (GMT). No. of bitstreams: 1 silva_prt_me_ilha.pdf: 5656626 bytes, checksum: 2c9618d4f90a4b6da73ade7a307dadcd (MD5) Previous issue date: 2017-08-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No cerrado brasileiro o Sistema Plantio Direto tem sido adotado expressivamente por agricultores. Contudo, o tráfego de máquinas e implementos em condições de alto teor de água no solo e as sucessivas adubações superficiais, tem provocado problemas de compactação e acúmulo de nutrientes na superfície, o que pode levar ao aumento da variabilidade espacial de nutrientes e na baixa expressão do potencial produtivo das culturas. Com a escarificação do solo, como prática para aliviar a compactação do solo, pode haver alterações na variabilidade horizontal de nutrientes devido à mobilização parcial do solo. Desta forma, a pesquisa teve como objetivo avaliar a variabilidade espacial dos atributos químicos do solo proporcionada pela escarificação do solo em Sistema Plantio Direto, e identificar por técnicas multivariadas, os principais atributos químicos do solo que melhor se relacionam com os componentes de produção e produtividade da soja. O experimento foi realizado num LATOSSOLO VERMELHO Distrófico, no ano agrícola 2015/16, na Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia - UNESP, Câmpus de Ilha Solteira, localizada no município de Selvíria - MS. O experimento consistiu-se em duas áreas de cultivo, uma sob Sistema Plantio Direto (SPD) implantado há 13 anos e outra em Cultivo Mínimo escarificado (CM). Para coleta dos dados, foram alocadas duas malhas geoestatísticas, uma em cada área de cultivo. Cada malha foi constituída de 51 pontos equidistantes com uma distância entre pontos de 10 m. Foram avaliadas a população final de plantas, a altura de inserção da primeira vagem, a altura de plantas, o número de vagens por planta, de grãos por planta, de grãos por vagem, a massa de 100 grãos, a produtividade de grãos e atributos químicos do solo. A produtividade de grãos de soja foi maior em SPD quando comparado ao CM escarificado. A escarificação diminuiu a variabilidade espacial dos atributos químicos do solo na camada de 0-0,10 m. Os valores de pH, teores de cálcio, magnésio e fósforo na camada de 0-0,10 m, bem como o teor de K de 0,10-0,20 m, são os atributos que mais contribuíram no aumento de produtividade da soja em SPD e em CM. Em SPD, a fertilidade do solo concentra-se na camada superficial, enquanto que no CM escarificado na camada de 0,10-0,20 m. Em SPD, a CTC apresentou cokrigagem positiva com a produtividade de grãos em superfície e subsuperfície do solo. Em CM, o pH e a saturação por bases apresentaram cokrigagem positiva com a produtividade de grãos na camada de 0-0,20 m, enquanto que a acidez potencial apresentou cokrigagem negativa. / In the Brazilian cerrado the no-tillage system has been adopted expressively by farmers. However, the traffic of machines and implements in conditions of high water content in the soil and successive superficial fertilizations has caused problems of compaction and accumulation of nutrients on the surface, which can lead to increased spatial variability of nutrients and low expression potential of crops. With soil scarification, as a practice to alleviate soil compaction, there may be changes in the horizontal variability of nutrients due to partial soil mobilization. The objective of this research was to evaluate the spatial variability of soil chemical attributes provided by soil scarification in no - tillage system, and to identify by multivariate techniques, the main soil chemical attributes that best relate to soybean yield and productivity components. The experiment was carried out in a dystrophic Oxisol, in the agricultural year 2015/16, in the Experimental Farm belonging to the Faculty of Engineering - UNESP (Ilha Solteira), located in Selvíria - MS. The experiment consisted of two cultivation areas, one under no-tillage system (NT) implanted 13 years ago and another in minimal cultivation scarified (MCS). To collect the data, two geostatistical meshes were allocated, one in each cultivation area. Each mesh was made up of 51 equidistant points with a distance between points of 10 m. The final population of plants, the height of insertion of the first pod, the height of plants, the number of pods per plant, of grains per plant, of grains per pod, the mass of 100 grains, the grain yield and soil chemical attributes were evaluated. The yield of soybean grains was higher in NT when compared to scarified MCS. Soil scarification decreased the spatial variability of soil chemical attributes in the 0-0.10 m layer. The values of pH, calcium, magnesium and phosphorus contents in the 0-0,10 m layer, as well as the K content of 0,10-0,20 m layer, are the attributes that contributed the most to increase soybean productivity in NT and MCS. In NT, the soil fertility is concentrated in the superficial layer, whereas in the MCS in the layer of 0,10-0,20 m. In NT, the CEC presented positive cokrigagem with grain yield at the surface and subsurface soil. In MCS, the pH and base saturation showed positive cokrigagem with grain yield in the 0-0,20 m layer, while potential acidity showed negative cokrigagem.

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