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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.
581

Aplicação superficial de calcário e gesso em manejo conservacionista de solo para cultivo de amendoim e aveia branca /

Marques, Rúbia Renata, 1978- January 2008 (has links)
Orientador: Carlos Alexandre Costa Crusciol / Banca: Dirceu Maximino Fernandes / Banca: Edson Lazarini / Banca: José Salvador Simoneti Foloni / Banca: Denizart Bolonhezi / Resumo: Estudos relacionados ao cultivo de amendoim no sistema de semeadura direta são escassos, principalmente relacionados com aplicação superficial de calcário e gesso. A aveia branca é uma das alternativas para o cultivo de inverno no Brasil, por produzir grãos para alimentação humana, forragem e adubo verde, diversificando a atividade agrícola, no entanto são inexistentes na literatura informações a respeito da calagem e gessagem superficiais nesta cultura. Em função do exposto, o presente trabalho teve por objetivo avaliar o comportamento das culturas de amendoim e aveia branca cultivadas no sistema semeadura direta, em área com aplicação superficial de calcário e gesso, bem como as conseqüências no movimento de bases no perfil do solo, na concentração de cátions solúveis na parte aérea, na nutrição e produtividade das culturas. O experimento foi conduzido nos anos agrícolas de 2004/2005 e 2005/2006 na Fazenda Experimental Lageado da Faculdade de Ciências Agronômicas - Campus de Botucatu, num Latossolo Vermelho distrófico. Foi utilizado o delineamento experimental em blocos casualizados com parcelas subdivididas e quatro repetições. As parcelas foram constituídas pela aplicação de quatro níveis de calcário dolomítico com PRNT = 71,2. As doses de calcário foram definidas de acordo com a análise química do solo na profundidade 0-0,2m para elevar a saturação por bases a 70% (2.000 kg ha- 1), metade da dose recomendada (1.000 kg ha-1), o dobro da dose recomendada (4.000 kg ha-1) e uma testemunha (sem aplicação). As subparcelas foram constituídas pela ausência e presença da aplicação de 2.100 kg ha-1 de gesso agrícola. Como cultura de verão foi utilizado o cultivar de amendoim (IAC 886) nos dois anos de condução do experimento em toda a área experimental e como cultura de inverno foi utilizado o cultivar de aveia branca (IAC 7) nos dois anos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: There have been few studies about peanut crop in no-tillage system mainly about superficial liming and gypsum application. White oat is an alternative for winter cropping in Brazil to be used as human food, forage and green manure; nevertheless, there is no information about superficial liming and gypsum application for this crop. Therefore, the objective of this work was to evaluate peanut and white oat yield as affected by superficial liming and gypsum application in no-tillage system as well as base movement in soil profile, concentration of water-soluble cations in the shoot of plants and plant nutrition. The experiment was carried out in the growing seasons of 2004/2005 and 2005/2006 in Botucatu, São Paulo State, Brazil, on a dystrophic Red Latosol. The experimental design was the completely randomized block with subdivided plots and four replications. The main plots consisted of four dolomite limestone levels with neutralization power of 71.2. Limestone levels were determined by soil chemical analysis in the 0-0.20m depth; the aim was to apply the recommended dose to raise base saturation up to 70% (2000 kg ha-1), half of the recommended dose (1.000 kg ha-1) and twice the recommended dose (4000 kg ha-1) besides the control, with no application. Subplots consisted of areas with and without gypsum application (2000 kg ha-1). Peanut (cultivar IAC 886) and white oat (IAC 7) consisted of the summer and winter crops cultivated in two growing seasons, respectively. The results of the present research showed that superficial liming affected soil acidity and increased Ca and Mg levels in the soil profile along with gypsum application, which contributed for the effects to be observed in deeper layers. Then, it was found that superficial liming showed residual effects and allowed fine lime particles to move down in the soil profile... (Complete abstract click electronic access below) / Doutor
582

Épocas de adubação nitrogenada na cultura do milho e sua influência na cultura subsequente, girassol, em sistema de semeadura direta /

Freire, Luciana Maria da Silva, 1979- January 2009 (has links)
Orientador: Dirceu Maximino Fernandes / Banca: Silvio José Bicudo / Banca: Carlos Sérgio Tiritan / Resumo: O rendimento de grãos de milho é influenciado pela disponibilidade de nitrogênio no solo durante o ciclo de desenvolvimento da planta. O objetivo deste trabalho foi avaliar em sistema de semeadura direta, os resultados obtidos com a adubação nitrogenada em pré-semeadura e em cobertura na cultura do milho analisando a produtividade de grãos desta cultura e da cultura subsequente, o girassol. O experimento foi conduzido em uma área no sistema de semeadura direta há cinco anos, no Sítio Santo Antônio em Pirassununga, SP no ano agrícola 2004/2005. Utilizou-se o delineamento experimental de parcelas subdivididas, sendo 3 híbridos de milho, 4 épocas de adubação e 5 repetições. A dose em cobertura de 102,5 kg ha-1 N, com o adubo 25-15-10, tendo como fonte de N o nitrato de amônio, foi aplicado nas seguintes épocas: Tratamento 1 (E1): testemunha (sem aplicação antecipada e sem cobertura de N); Tratamento 2 (E2): todo N em cobertura com milho de 3 a 4 folhas expandidas; Tratamento 3 (E3): em cobertura metade da dose de N com milho de 3 a 4 folhas expandidas e o restante de N com milho de 7 a 8 folhas expandidas; e Tratamento 4 (E4): metade da dose de N em pré-semeadura (15 dias antes da semeadura), e a metade restante de N em cobertura com milho de 3 a 4 folhas expandidas. Após a colheita do milho semeou-se girassol nestas áreas. Como resultado para o milho tem-se os híbridos se comportaram de maneira diferentes quanto as épocas de adubação de cobertura de N, onde os híbridos AG 8060 e Pointer não apresentam diferenças significativas entre a E2, E3 e E4; já o híbrido DKB 390 apresenta sua melhor resposta na E2 e a menor média na E4. Para a cultura do girassol, as épocas de adubação de milho não interferem na produtividade, porém, o girassol semeado após o híbrido DKB 390 apresenta menor produtividade quando comparado com os híbridos AG 8060 e Pointer. / Abstract: The income of grains of corn is influenced by the avaiability of nitrogen in soil during the cycle of a plant development. The mainly objective of this research evaluate the results obtained with the nitrogen fertilization in pre-sowing and in covering of the culture of corn in a no-tillage system analyzing the productivity of grains from this culture and the subsequent culture, the sunflower. The experimented was in an area were there had already been developed the no-tillage system for five years, in the Santo Antônio Farm in Pirassununga, SP, in agricultural year 2004/2005. Used the experimental outline of subdivided parcels, being 3 corns hybrids, 4 timings of fertilization and 5 repetitions. The dose covering 102,5 kg ha-1 N, with 25-15-10 fertilizer, and as a source of N ammonium nitrate was applied at the following times: Treatment 1 (E1): testimony ( without anticipated application of without application of N in covering); Treatment 2 (E2): all N in covering with corn of 3 to 4 expanded leaves; Treatment 3 (E3): in covering with half dose of N with corn of 3 to 4 expanded leaves and half of the left dose of N with corn of 7 to 8 expanded leaves; and Treatment 4 (E4): half dose of N in pre-sowing (15 days before sowing), and half dose of N in covering with corn of 3 to 4 expanded leaves. After of harvest of corn was sowing sunflower this area. As result for the corn has been the hybrids behaved as different seasons as the times of covering fertilization of N, where the hybrid AG 8060 and Pointer not differ significantly between the E2, E3 and E4; since the hybrid DKB 390 presents its best response in the E2 and the lowest average in the E4. For the culture of sunflower, the times of fertilization of corn does not interfere with productivity, however, the sunflower sown after the hybrid DKB 390 has lower productivity compared to the hybrid AG 8060 and Pointer. / Mestre
583

Welchen Nutzen haben Sensoren? Wo bleibt das 1x1 des Bodens?

Graf, Klaus 15 November 2017 (has links)
No description available.
584

Visionen und Strategien in der Bodenbearbeitung: Entwicklungsstationen im Zeitraffer eines Konstrukteurs von 1984-2017

Giesen, Gottfried 14 November 2017 (has links)
No description available.
585

Einsatz von Sensortechnik in der Bodenbearbeitung – Nutzen für die Beratung

Dölger, Detlef, Willerding, Markus 15 November 2017 (has links)
• Wo stehen wir bei Precision/Smart Farming – Immer mehr Elektronik? • Einstellbarkeit von Maschinen • Verschneiden von Informationen – Funktioniert das automatisch? – Analog und Digital kombinieren • Das Ziel ist der Weg – aber kennen wir es? • Wahl des Bodenbearbeitungswerkzeugs • Beispiele für die Anwendung – Bodenbearbeitung – Saat • Und die Beratung?
586

The Effects of Two Types of Reclamation on Abandoned Non-Coal Surface Mines in Cuyahoga Valley National Park, Ohio

Ruhm, Catherine Terese 04 December 2018 (has links)
No description available.
587

Denitrification and nitrous oxide dynamics in the soil profile under two corn production systems

Elmi, Abdirashid A. January 2002 (has links)
No description available.
588

Soil microbial dynamics in response to tillage and residue management in a maize cropping system

Spedding, Timothy Andrew January 2002 (has links)
No description available.
589

Erosion and Mobilization Controls on Soil Organic Geochemistry, Form, and Flux within Intensively Managed Agricultural Landscapes

Tingyu Hou (11191914) 28 July 2021 (has links)
<p>Soil organic carbon (OC) is one of the most important terrestrial carbon pools and plays a major role in climate regulation, water quality, provisional services, and numerous other ecosystem functions. The conversion of natural vegetation and the supporting soil to intensively managed agricultural systems put soil at risk for loss due to erosion and enhanced microbial degradation with loss rates increased by orders of magnitude above the pre-managed system. The process has negatively impacted agricultural productivity on hillslopes by diminishing soil health, as well as the quality of stream water and coastal aquatic environments, and it is an important but as of yet poorly quantified factor in the region’s terrestrial C budgets. There have been substantial debates on the role of erosional and depositional processes on the landscape as a control on exchange of C between the land surface and the atmosphere. A central aspect of the debate stems from the limited data regarding the fate of soil erosion-induced transport of OC through stages of detachment and splash, transport and redistribution, deposition and burial. The overarching purpose of this thesis is to evaluate how dynamic patterns of soil OC erosion due to intensive agricultural management influences soil aggregate strength, the chemical nature of mobilized organic particles, and connectivity and sourcing between hillslope and streams. Using both simulated and natural, short-term, event-based erosive rainfall processes, with a multiproxy geochemical approach, we attempt to develop a comprehensive understanding of how upland watershed mechanistic controls soil movement and associated chemical alterations to the material exported through dissected segments from hillslope to the fluvial network. </p> <p>Our results demonstrate that erosive processes on hillslope connects between terrestrial sources to receiving potential deposition settings, actively ‘filter’ soil aggregates and particles and associated OC at each erosional stage (i.e., detachment and transport downhill/downstream), with distinct geochemistry in low relief and poorly drained agricultural systems, like the CCW. Complex interactions among tillage intensity, tillage practice-induced, oriented surface roughness, and storm-induced hydrological connectivity, that potentially impact the fate of these transported OC upon decomposition, deposition and burial, and have important implications for predicting landscape level heterogeneity in surface and buried soil chemistry upon mobilization and burial, as well as the dynamics of sourcing and transformation of material exported to inland water systems.</p>
590

The Use of Biological Soil Health Indicators to Quantify the Benefits of Cover Crops

Wu, Alexander 05 April 2023 (has links) (PDF)
Soils provide many essential functions that support the world. With a decline in soil health, these functions also decrease in efficiency, and can threaten the health of billions of people around the world. Typically, soil health tests do not use biological indicators, however microbes drive and perform vital functions to increase soil health. One way to increase soil health is through the use of cover crops to reduce soil erosion during fallow periods, increasing soil organic matter, as well as collecting nutrients from soil into their biomass. These cover crops are then terminated through various methods such as herbicides, disk tillage, or no tillage. The termination method can have an impact on soil health, by chemically affecting soil microbes with herbicides, disturbing soil, microbial communities, and fungi with tillage, or creating residue barriers on the surface of soil such as with using roller crimping (no tillage). Fertilization can also affect soil health, controlling rates of nutrient turnover and decomposition through the needs of microbes for carbon and nitrogen. This study quantifies the effects of four termination methods and four fertilization treatments on soil biological indicators during one growing season of sweet corn. Plots that were not tilled and terminated using roller crimping showed highest rates of decomposition, as well as increased labile carbon pools to feed microbes slowly throughout the growing season. Microbial activity was also observed to respond to fertilization, as patterns in activity spiked directly after fertilization. This study informs agricultural land management by the usage of biological indicators to further support the use of cover crops to increase soil health along with using no-till termination methods. Root biomass contributions toward soil health was also investigated, and how they may be affected by tillage.

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