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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.
31

Decomposição e mineralização de adubos orgânicos acondicionados em cápsulas porosas / Decomposition and nutrient mineralization of organic fertilizers into porous capsules

Pereira, Dercio Ceri 11 July 2011 (has links)
Made available in DSpace on 2017-05-12T14:48:15Z (GMT). No. of bitstreams: 1 Dercio_texto completo.pdf: 1537971 bytes, checksum: 6f0c7593eb1fec03ef4d321153f4df61 (MD5) Previous issue date: 2011-07-11 / The western Paraná is a region that rears poultry, swine and cattle. Such activities produce significant amounts of waste. The increase on its amount is due to an animal intensive system, whose management is in feedlot and adopts large herds per unit area. The use of organic waste in agriculture is increasing due to some awareness of organic manure application in the studied region. Thus, this study aimed at investigating the decomposition of organic fertilizers produced in western Paraná as well as nutrients mineralization and the effect of their contents on soil bellow porous capsules, without and with irrigation. Porous capsules (ceramic candles) were used, whose diameter was 5.1 cm and 9.8 cm length. The experimental design was in randomized blocks with five treatments. Two trials were carried out: one with 100 capsules under irrigation and the second one without irrigation. The treatments were: pelletized vermicompost (V); pelletized vermicompost + phosphate Arad (VP); compost (C); biodynamic compost (BC); poultry litter of three batches (PL). In order to place the capsules, furrows were opened deeper than the capsules diameter (5 cm) and covered with a layer of soil. The capsules were put horizontally on soil profile. Irrigation was by drip. Samples of such organic materials were collected for analyses at 7, 14, 35, 65 and 100 days. The material inside capsules was oven-dried and weighed to determine decomposition by difference of mass. The contents of nitrogen, phosphorus, potassium, calcium, magnesium, zinc, iron, copper and manganese of different organic materials were evaluated with and without irrigation. For soil, the same nutrients of organic materials were analyzed, except for nitrogen; besides, carbon contents were determined. The decomposition rate was estimated by logarithmic equations, as well as half-life of organic materials. The PL treatment without irrigation showed higher decomposition of organic materials (V, VP, C, CB), as well as for the irrigation system. On the other hand, the decomposition of organic materials (V, VP, C, CB) in the irrigated area was superior than without irrigation. The PL mineralization for nutrients as carbon, nitrogen, phosphorus, potassium, sodium, zinc, iron, copper and manganese was higher in non-irrigated area when compared with the other treatments and in relation to the area under irrigation. The organic materials (V, VP, C and CB) in relation to nutrients as carbon, nitrogen, phosphorus, potassium, sodium, zinc, iron, copper and manganese showed a better answer in mineralization when under an irrigation system. / A Região Oeste do Paraná possui criações de aves, suínos e bovinos. Tais atividades geram quantidades significativas de resíduos. O aumento no volume de dejetos é devido à intensificação da produção de proteína animal, que faz uso de confinamento e adota grandes plantéis de animais por unidade de área. A utilização dos resíduos orgânicos na agricultura está aumentando, devido à conscientização acerca da utilização da adubação orgânica na Região. Assim, o objetivo deste estudo foi verificar a decomposição dos adubos orgânicos, gerados na Região Oeste do Paraná, bem como a mineralização dos nutrientes e o efeito sobre os teores destes no solo abaixo das cápsulas sem irrigação e com irrigação. Foram utilizadas cápsulas porosas, com diâmetro de 5,3 cm e 9,8 cm de comprimento. O delineamento experimental foi em blocos casualizados com cinco tratamentos. Foram realizados dois experimentos com 100 cápsulas irrigadas e 100 cápsulas sem irrigação. Os tratamentos foram: vermicomposto peletizado (V); vermicomposto peletizado + fosfato de Arad (VF); composto (C); composto biodinâmico (CB); cama de aviário de três lotes (CA). Para a acomodação das cápsulas, foram abertos sulcos com profundidade superior ao diâmetro das cápsulas, e cobertas com uma camada de solo. As cápsulas foram dispostas no sentido horizontal em relação ao perfil do solo. A irrigação foi por gotejamento, efetuada a cada dois dias. As coletas dos materiais orgânicos para as análises foram aos 7, 14, 35, 65 e 100 dias. O material orgânico do interior da cápsula foi seco em estufa e pesado para determinar a decomposição por diferença de massa. Foram avaliados teores de nitrogênio, fósforo, potássio, cálcio, magnésio, zinco, ferro, cobre e manganês dos materiais orgânicos, com e sem irrigação. Para o solo, foram analisados os mesmos nutrientes dos materiais orgânicos, exceto nitrogênio, mas foram determinados os teores de carbono. A taxa de decomposição anual foi estimada por meio de equações logarítmicas, assim como a meia-vida dos materiais orgânicos. A CA, sem irrigação, apresentou maior decomposição entre os materiais orgânicos V, VF, C, CB e em relação ao sistema irrigado. Por outro lado, a decomposição dos materiais orgânicos V, VF, C, CB, na área irrigada, foi superior em relação à área sem irrigação. A mineralização da CA para os nutrientes carbono, nitrogênio, fósforo, potássio, sódio, zinco, ferro, cobre e manganês foi maior na área sem irrigação, em comparação aos demais tratamentos e em relação à área com irrigação. Os materiais orgânicos V, VF, C e CB para os elementos: carbono, nitrogênio, fósforo, potássio, sódio, zinco, ferro, cobre e manganês apresentaram superioridade na mineralização com a utilização do sistema irrigado.
32

Paleobiological assessment of controls underlying long-term diversity dynamics

Cárdenas, Andrés L. 01 January 2012 (has links)
Deciphering the factors underlying both long-term patterns of diversity and taxonomic turnover rates (i.e., extinction, and origination) has been one of Paleobiology's major foci for the past three decades. The importance of documenting these components is that they will expand our ability to interpret and model the evolutionary processes underlying those trends, highlight the evolutionary impact of historical events, and contribute to the formulation of robust predictions about the future of global diversity in response to the current anthropologically driven environmental changes. Accordingly, the first part of this study examines the possible occurrence of global marine evolutionary environmental controls into a `deep-time' perspective, using a statistical time-series approach between the most recent Phanerozoic global marine generic origination rates with coeval mean global marine geochemical and geological signatures of environmental proxies. After this examination, significant positive correlations were found between changes in origination rates and global mean signatures of 87Sr/86Sr and δ34S, as well as a significant negative correlation between variability in both origination rates and eustatic sea level. They suggest that over secular timescales, nutrient availability, as controlled by continental weathering, phosphorus recycling, and the relative extent of shelf exposure, is an important regulator of genus-level origination in the marine realm, with periods of increased nutrient availability associated with higher origination rates.
33

Unraveling the causal links between ecosystem productivity measures and species richness using terrestrial ferns in Ecuador

Salazar, Laura 01 November 2012 (has links)
Este trabajo está enfocado en la relación entre la productividad y la riqueza de especies de helechos terrestres, y en la disponibilidad de nutrientes a través de un gradiente altitudinal en Ecuador. El trabajo de campo fue realizado durante tres años entre 2009 y 2011, el cual fue llevado a cabo en 8 niveles altitudinales entre 500m y 4000m en la Cordillera Oriental de los Andes ecuatorianos. Diversidad, biomasa, productividad y caracteres funcionales de las hojas de los helechos terrestres fueron estudiados en tres cuadrantes permanentes de 400m2 por cada elevación. Se reportaron un total de 91 especies de helechos terrestres en 32 géneros y 18 familias. A través del gradiente altitudinal, el pico más alto de riqueza de especies se registró en elevaciones medias y la riqueza de especies estuvo débilmente relacionada a medidas de productividad del ecosistema y más fuerte relacionado a la productividad de los hehechos terrestres, lo cual podría estar determinado por un incremento en el número de individuos de helechos y por la disponibilidad de nichos. Sin embargo, en cada nivel altitudinal la relación entre la riqueza de especies de helechos y la productividad de helechos fue negativa, lo cual principalmente se debe a la competencia interespecífica; es decir, en ambas escalas espaciales de este estudio, la diversidad de helechos parece estar limitada por el número de nichos disponibles y la competencia para ocupar estos nichos. Al comparar los caracteres funcionales de las hojas de helechos y árboles a través del gradiente altitudinal se observó similaridades entre ellos. Sin embargo, se encontró una diferencia en el área específica de las hojas entre helechos y árboles, lo cual refleja los diferentes niveles de luz de ambas formas de vida. Respecto los cambios altitudinales en biomasa y productividad de helechos y árboles se encontró una notable diferencia entre estas dos formas de vida, lo cual apoya la hipótesis de que ambos grupos de plantas están creciendo limitados por diferentes factores.
34

Sustainable restoration of mine sites

Krisnayanti, Dewi January 2009 (has links)
A sustainable approach to restoration of the post-mining landscape involves creating conditions where a viable growth medium can be established with the minimal amount of fertiliser inputs over a period of time. Ideally, this growth medium should comprise a combination of minerals, organic matter, and biological components with have the capacity to retain and release nutrients over time. When combined with a re-vegetation scheme appropriate to the biogeographic area, a self-sustaining ecosystem can be established. Regulatory requirements for mine restoration typically require the use of topsoil, which is often in limited supply. However, overburden is commonly present in vast quantities and has the potential to be used as a restoration substrate with appropriate amendments. There are significant gaps in our understanding of factors relating to the use and amendment of overburden as a growing medium. The main objective of this study was to investigate and quantify the effects of inorganic and organic amendments and weathering on nutrient availability and plant growth in topsoil and overburden material obtained from the OceanaGold Globe Progress mine at Reefton, New Zealand. A series of glasshouse experiments were carried out on topsoil, fresh overburden and mullock (old waste rock) amended with biosolids, green manure, sawdust, lime and mineral fertiliser nutrients (nitrogen (N) and phosphorus (P)). R esults demonstrated that 300 kg N ha⁻¹ was sufficient to overcome N deficiency in topsoil, while 100 kg P ha⁻¹ was required to overcome P deficiency. Addition of biosolids to topsoil and overburden increased plant biomass production, without increasing heavy metal concentrations. Amendment of overburden significantly affected weathering rates by accelerating the formation of secondary minerals. In particular, lupin green manure accelerated the formation of organic iron (Fe) and aluminium (Al) organic complexes, resulting from the decomposition of the green manure and release of Fe from primary minerals. Results revealed that wineberry and red beech required 200 kg N ha⁻¹ for optimum growth. Overall, the findings of this research identified key parameters for effective utilisation of overburden as a restoration substrate. A sustainable restoration method for managing the topsoil and/or any overburden or waste rock material remaining at mine sites can be achieved by careful selection of organic amendments and allowing an initial weathering period.
35

From wood to waste and waste to wood : aspects on recycling waste products from the pulp mill to the forest soil /

Rothpfeffer, Caroline, January 2007 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.
36

Produção e efeitos de biofertilizante bioprotetor com quitosana na alface

FELIX , Fabiana Ferreira 29 February 2012 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2016-08-02T14:01:59Z No. of bitstreams: 1 Fabiana Ferreira Felix.pdf: 754691 bytes, checksum: b26fddd7eec71d3c98c4aa2e7f77a373 (MD5) / Made available in DSpace on 2016-08-02T14:01:59Z (GMT). No. of bitstreams: 1 Fabiana Ferreira Felix.pdf: 754691 bytes, checksum: b26fddd7eec71d3c98c4aa2e7f77a373 (MD5) Previous issue date: 2012-02-29 / Nitrogen is one of the macronutrient that affects plant growth, and is usually not found on the rocks. Thus the study involving N-fixing bacteria with free living or symbiotic associations are of extreme importance for the development of agriculture. The objective of this study was to evaluate the enrichment in N of the organic matter (earthworm compound) by inoculation with free living diazotrophic bacteria and the addition of fungi chitosan adding Cunninghamella elegans that contain chitosan in their cell wall, a biopolymer that have the properties to act in the control of plant diseases. Diazotrophic bacteria were isolated from Brazilian soils and selected at the Nucleus of Biologic Nitrogen Fixation in the Tropics (NBNFT/UFRPE). The diazotrophic bacteria, were isolated in silica gel plaques and grown in liquid culture (LG medium), maintained under shaking during 15 days (± 28ºC). The biofertilizer (NPKB) and the Protector (NPKP) production were processed in laboratorial assay using plastic trays, and in field conditions in furrows at the University Federal Rural of Pernambuco Horticultural Station. In field the diazotrophic bacteria was inoculated adding 30 L of the culture medium (108 viable cells mL-1) for each 3000 kg of organic matter (earthworm compound). The fungus C. elegans was grown in potato-dextrose medium (PD) and the inoculation was processed in the same manner described for the diazotrophic bacteria. In all assays samples were collected weekly (T0, T7, T14, T21, T28, T35 e T42, after inoculation) for chemical analyzes. By the results it was observed that the time for maximum efficiency for increment of the biological N fixation by the free living diazotrophic bacteria was achieved at 35 days after inoculation and N increase up to 100% compared with the initial N (T0). The research work showed the possibility to obtain a mixed fertilizer (NPKB) with higher N rate due to the free living diazotrophic bacteria inoculation. The bioprotector (NPKP) increments the N, P and K content of the product and have potential to provide nutrients for plants. / O nitrogênio é o macronutriente mais limitante para o crescimento das plantas, e normalmente não é encontrado diretamente nas rochas. Assim o estudo com bactérias fixadoras de N sejam de vida livre, associativas ou simbióticas são de extrema importância para o desenvolvimento da agricultura. O objetivo do presente trabalho foi avaliar o enriquecimento em N na matéria orgânica (húmus de minhoca) por inoculação com bactéria diazotrófica de vida livre e adição de quitosana fúngica pelo fungo da Ordem Mucorales (Cunninghamella elegans) que possui na parede celular a quitosana, biopolímero que atua no controle de doenças de plantas. A bactéria diazotrófica de vida livre foi selecionada no Núcleo de Fixação Biológica do N2 nos Trópicos da UFRPE. As bactérias foram isoladas em placas de sílica gel, cultivadas em meio de cultura (LG líquido), e mantidas em crescimento sob agitação por 15 dias (± 28ºC). A produção do biofertilizante (BNPK) e do Bioprotetor (PNPK) foi realizada em ensaios em laboratório (bandejas) e em condições de campo usando canteiros da Horta Experimental da UFRPE. No experimento em campo na inoculação com bactéria diazotrófica de vida livre foram adicionados 30L de meio (108 células viáveis mL-1) para cada 3000 kg de matéria orgânica (Húmus de minhoca). O fungo C. elegans foi cultivado em meio batata dextrose (BD) e a inoculação feita da mesma forma descrita para o ensaio com bactéria diazotrófica. Em todos os experimentos foram coletadas amostras no início, e semanalmente, após a inoculação (T0, T7, T14, T21, T28, T35 e T42). Os resultados demonstram que o período de máxima eficiência no processo da fixação biológica de N2 pela bactéria diazotrófica é atingido aos 35 dias de incubação, com um incremento de N na faixa de 100% em comparação com o N inicial (T0). O trabalho mostra a possibilidade de obtenção de biofertilizante misto (BNPK) com maior nível de N pela inoculação com bactéria diazotrófica de vida livre. O Bioprotetor (PNPK) com quitosana fúngica (PNPK), promove aumento de N, P e K no produto e tem potencial de disponibilizar nutrientes para a planta.
37

Disponibilidade de água e de nutrientes do solo e desenvolvimento do eucalipto em uma microbacia hidrográfica no município de Pinheiro Machado - RS. / Availability of water and nutrients in the soil and the development of eucalyptus in a hydrographic microbasin in the city of Pinheiro Machado RS.

Severo, Carlos Roberto Soares 28 May 2009 (has links)
Made available in DSpace on 2014-08-20T14:36:56Z (GMT). No. of bitstreams: 1 Tese_Carlos_Roberto_Soares_ Severo.pdf: 7267743 bytes, checksum: 6e2b8a9babdbf6bf9ff708708ea6d3ee (MD5) Previous issue date: 2009-05-28 / The knowledge of the distribution of the soils allows the planning of agricultural activities in a way to maximize the productivity of cultures and reduce the environmental degradation. That way, the water and nutrient availability to the plants become of great importance and may be evaluated by means of physical, chemical and mineralogical analysis and its interpretation of local conditions. This study had the objective of surveying and mapping the soils of a hydrographic microbasin used in the culture of eucalyptus, relating its physico-hydrical and chemical characteristics with the culture development. The study area has 63,53 hectares and belongs to VPC Florestal, located in the Alamos Farm in the city of Pinheiro Machado, where the culture of eucalyptus saligna is being cultivated. To represent the mapping units were characterized in field and collected 9 soil profiles, representing the classes of Argisoils, Cambisoils, Chernosoils, Luvisoils and Neosoils. In relation to total nutrients, the class of soil that presented the greater quantity of available nutrients in t.ha-1 in the microbasin was the Cambisoil, followed by Luvisoil, Chernosoil, Neosoil and Argisoil. Relating to total nutrients, the class of soil that showed a greater quantity in t in the microbasin was the Argisoil, followed by the Neosoil, Luvisoil, Chernosoil and Cambisoil. The soils present in the hydrographic microbasin of the Alamos Farm have a total of 1300 basic available cations and a total of 15770 basic cations. As for the water availability, the Alamos Farm has a storing capacity in its soil of 121245m³ of water, of those 20778m³ available to the plants. Relating to the development of eucalyptus, the results show there was a differentiated growth in different soil mapping units, and the greater growth was showed in the class of Argisoil. / O conhecimento da distribuição dos solos permite o planejamento das atividades agrícolas de forma a maximizar a produtividade das culturas e a reduzir a degradação ambiental. Dessa forma, a reserva e a disponibilidade de água e de nutrientes para as plantas se tornam de grande importância, podendo ser avaliadas por meio de análises físicas, químicas e mineralógicas dos solos e da sua interpretação para as condições locais. Este estudo teve por objetivo, fazer um levantamento e mapeamento dos solos em uma microbacia hidrográfica utilizada com a cultura do eucalipto, relacionando suas características físico-hídricas e químicas com o desenvolvimento da cultura. A área de estudo, com 63,53 hectares, está localizada na Fazenda Álamos, pertencente a VCP Florestal, no município de Pinheiro Machado, onde está sendo cultivada a cultura do eucalipto saligna. Para representação das unidades de mapeamento foram caracterizados a campo e coletados 9 perfis de solo, representando as classes dos Argissolos, Cambissolos, Chernossolos, Luvissolos e Neossolos. Em relação aos nutrientes, a classe de solo que apresentou uma maior quantidade de nutrientes disponíveis em t.ha-1, na microbacia, foi o Cambissolo, seguido do Luvissolo, do Chernossolo, do Neossolo e dos Argissolos. Em relação aos nutrientes totais, a classe de solo que apresentou uma maior quantidade em t.ha-1, na microbacia, foi o Argissolo, seguido do Neossolo, do Luvissolo, do Chernossolo e do Cambissolo. Os solos presentes na microbacia hidrográfica da Fazenda Álamos, possuem um total de 1300t.ha-1 de cátions básicos disponíveis e um total de 15770t.ha-1 de cátions básicos totais. Quanto à disponibilidade de água, a microbacia da Fazenda Álamos, possui uma capacidade de armazenamento de água em seus solos de 121245m3 de água, destes 20778m3 disponíveis as plantas. Em relação ao desenvolvimento do eucalipto, os resultados mostram que houve um crescimento diferenciado, conforme a unidade de mapeamento de solos, sendo observado o maior crescimento na classe dos Argissolos.
38

The Tanzanian Minjingu phosphate rock : possibilities and limitations for direct application /

Szilas, Casper. January 2002 (has links) (PDF)
Ph.d.-afhandling. Den Kongelige Veterinær- og Landbohøjskole, 2002. / Haves også i trykt udg.
39

Soil pH and nutrient uptake in cauliflower (Brassica oleracea L. var. botrytis) and broccoli (Brassica oleracea L. var. italica) in northern Sweden : multielement studies by means of plant and soil analyses /

Magnusson, Margareta, January 1900 (has links) (PDF)
Diss. Umeå : Sveriges lantbruksuniv.
40

Matching the availability of N mineralised from green-manure crops with the N-demand of field vegetables /

Båth, Birgitta, January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

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