• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 37
  • 34
  • 20
  • 7
  • 7
  • 7
  • 7
  • 7
  • 6
  • 3
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 126
  • 126
  • 49
  • 20
  • 19
  • 19
  • 14
  • 13
  • 12
  • 11
  • 9
  • 8
  • 8
  • 8
  • 8
  • 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.
81

A laboratory and glasshouse investigation on the effect of liming with fly ash and processed stainless steel slag on two contrasting South African soils.

Ndoro, Esina Tambudzayi. January 2008 (has links)
Soil acidity is a major land degradation problem that limits crop production globally. The high cost of traditional liming materials (calcitic limestone, dolomite etc.) and the vast areas of land that require liming have led to the exploratory utilisation of alkaline industrial by- products such as fly ash and stainless steel slag. The liming potential and effects of liming with fly ash (from the Duvha power station) and processed stainless steel slag (Calmasil) on two acid soils were investigated in this study. The quality of fly ash and Calmasil as liming materials and their potential impacts on the soil quality and plant growth were investigated. The effects of liming with these materials on soil pH, EC, extractable Al, Mn, base cations and trace elements were investigated in an incubation experiment. A glasshouse trial was conducted to assess the effects of these materials on the growth of an acid intolerant crop, perennial rye grass. The incubation and glasshouse study were of a factorial design with two acid soils (the Avalon and Inanda soils), three materials (fly ash, Calmasil and lime); and five application rates of 0, 50, 100, 200 and 400% of the recommended optimum liming rate (OLR) for the growth of perennial rye grass. Characterization of fly ash showed that the major elements (>5%) present (Si > Al > Fe) are not comparable to lime (Ca > Si > Mg) and that it has a low liming potential (calcium carbonate equivalence (CCE) of 9.6%) in comparison to lime. The chemical composition of Calmasil is comparable to lime with Ca > Si > Mg as the major elements and it has a very high liming potential (CCE = 97%). The incubation experiment showed that adding fly ash and Calmasil increased the pH of both soils. However, at the optimum liming rate (100% OLR), only the treatment with Calmasil in the Avalon soil attained pH levels within the desired pH range. Extractable Al and Mn decreased with addition of fly ash and Calmasil to levels comparable to lime in the incubated soils. Addition of fly ash and Calmasil also increased the extractable base cations of both soils. The yield-response of perennial rye grass to treatments in both soils was in the following order: fly ash > Calmasil > lime. Application of fly ash at > 200% OLR in the Avalon soil caused injury of ryegrass. Application of fly ash and Calmasil at lower rates has great agronomic potential in ameliorating soil acidity. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.
82

Ground motion amplification of soils in the upper Mississippi Embayment

Romero, Salome M. 05 1900 (has links)
No description available.
83

A comparative study of the BCR sequential and batch extractions for wastes and waste-amended soil.

Elephant, Dimpho Elvis. January 2010 (has links)
The use of standard soil tests to assess waste materials has become a common practice in waste management. However, the suitability of using standard soil tests on waste materials is questionable. Therefore, this investigation was undertaken to compare commonly used chemical extraction methods for their ability to extract elements from soil, waste, and soil-waste mixtures. This was carried out by: · Assessing the effects of extraction time on the extractability of Al,Ca, Co, Cu, Fe, Mg, Mn, Ni, Pb, S, Si, and Zn; · Assessing the comparability between single and sequential extraction. Two manganese rich wastes namely electro-winning waste (EW) and silicate-rich smelter slag (SS) and an acid soil (Inanda, Ia) were used for this study. Waste amended soils were obtained by incubating the EW and SS with Ia soil at field capacity at a rate of 20 g kg-1 and 120 g kg-1 soil respectively, and were sampled at day 0, 7, 28, 56, and 140. The effect of extraction time was assessed on the EW, SS, and Ia soil with carbonated water used in the acid rain test conducted at 16, 20, 30, and 50 hours. The equilibration time was different for different materials and elements. The concentration of Al and Zn did not change appreciably with increasing extraction time in the EW. Similar results were found for Mg, S, and Si in the SS and S in the Ia soil. This was attributed to ‘equilibrium’ being reached before 16 hours. The equilibration time of 20 hours which would release the exchangeable and specifically adsorbed elements was obtained for Co, Mg, Si, S, and Mn in the EW. The concentration of Ca decreased with extraction time in the EW and was attributed to readsorption. The concentration of Ca and Mn in the SS and Al, Fe, and Si in the Ia soil increased with extraction time and the ‘equilibrium’ was not reached even after 50 hours. This was attributed to the release of elements due to dissolution of minerals. In the comparison between Community Bureau of Reference (BCR) sequential and batch extraction, the concentrations of Ca, Co, Mg, Mn, and S were higher in batch extraction than in sequential extraction, particularly for the EW and the EW treated soils. This was possibly caused by the readsorption of released elements during water extraction. On the contrary, sequential extraction had higher concentration of Al and Fe compared to batch extraction for the EW, Ia soil, SS treated soils, and EW treated soils. These were attributed to a continued desorption of elements and dissolution of minerals due to exposed surfaces which occurs in sequential extraction. The comparison between single and sequential extraction for the BCR sequential extraction showed that hydroxylammonium chloride (HAC) applied in sequential extraction had higher concentration of Al, Co, Fe, Pb, and Zn than the single HAC extraction. This was probably due to incomplete dissolution of minerals, precipitation of amorphous minerals, and readsorption of released elements occurring for a single HAC extraction. These were minimised for hydrogen peroxide (H2O2) extraction and hence comparability between single and sequential H2O2 extraction was observed. This was probably due to the presence of complexing agent in the extracting reagent which would minimise the formation of secondary precipitates and hence, improved dissolution of minerals was obtained. Similarly, the concentrations of elements were comparable between single and sequential aqua regia extraction. These results indicated that comparability is improved between single and sequential extraction when aggressive conditions are used. The results from this investigation indicated that when chemical extraction methods are applied to wastes, the effects of the waste properties on the results of extraction need to be well understood. Consequently, when the chemical extraction methods are used in waste management scenarios certain modifications might have to be made. These modifications include the use of a high solution:solid ratio and an extracting solution which has high complexing ability / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.
84

The use of magnetic susceptibility measurements to delineate wetlands in KwaZulu-Natal, South Africa.

Watson, Megan. January 2002 (has links)
The aim of this research was to investigate the possibility of using soil magnetic susceptibility to differentiate wetland soil from non0wetland soil, thereby enabling the identification of a wetland boundary. The initial methodology to test the viability of using magnetic susceptibility for wetland delineation was carried out at nine sites in three areas of Kwazulu-Natal, South Africa. Changes in vegetation were used to identify the permanently, seasonally and temporarily wet zones at each site to provide a quick indication of the various boundaries. At least one transect was studied at every site, extending from the outer edge of the temporary zone to the water's edge. Magnetic susceptibility readings, soil samples and/or elevations were taken in each zone. It was found that the magnetic susceptibility readings could be used to differentiate between the various wetland zones but boundaries were not identified due to the reconnaissance nature of the work, a specific protocol had yet to be discovered. This methodology was a reconnaissance phase to assess the potential of using soil magnetic susceptibility. A second methodology was designed specifically to identify a wetland boundary. The wetland zones were identified using vegetation indicators from the South African field procedure for delineating wetlands. Magnetic susceptibility readings were done on transects perpendicular to the suspected boundary and a critical value was identified. A magnetic susceptibility boundary was marked according to the critical value and verified by taking readings along transects parallel to it on both sides. The boundary was then identified using South African field procedure according to soil indicates. The soil data showed a similar boundary to the magnetic susceptibility boundary but indicated a 'boundary zone' of approximately l2m in width rather than a specific line. A final methodology was planned to improve the resolution of the magnetic susceptibility boundary. A grid was laid out over a strip through the wetland including the boundary area on both sides. This was to provide accurately spaced points at which to take magnetic susceptibility readings and elevations. The critical value, a value that separates wetland from non-wetland soil, was identified and verified using soil indicators. The field procedure was more difficult to carry out than using the magnetic susceptibility sensor, yet both methods identified the same boundary with a resolution of about 3m. This initial study demonstrates the potential for using magnetic susceptibility for wetland delineation. Although the results at the final site proved the method to be successful, it was not suitable for use at all sites and the results were often difficult to interpret. Limitations include factors such as plinthic horizons close to the soil surface and shallow, rocky soils. Thus further research is required before magnetic susceptibility can be used to delineate wetlands in KwaZulu-Natal, South Africa. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.
85

Examination of the relationship between the form and function of medieval or later field systems in Scotland using soil micromorphology

Chrystall, Fiona H. January 1998 (has links)
A possible relationship between the form and function of medieval or later field systems in Scotland is tested using soil micromorphology and quantitative analysis techniques. Existing survey data is used to develop a classification system of six medieval or later field systems in Scotland. The topsoils of two abandoned field systems are sampled from field units representing the range of field classes identified during the field system classification of each site. Soil micromorphology is used to identify existing micromorphological evidence of past anthropogenic influences in these soils. Two methods of soil thin section description are employed using a specially devised coding method to increase the speed of soil thin section description; Level 1 description records a single entry per slide for 32 micromorphological parameters, Level 2 uses a 1cm2 grid system over each slide to record an entry for alternate gridsquares for 15 micromorphological parameters. The soil micromorphological results are quantitatively analysed using HCA and non-parametric statistical tests to test for a possible relationship between the form and function of the field units within each field system. The results indicate that automated image analysis and quantitative analysis techniques can be successfully applied to existing data to produce classification maps for medieval or later field systems which reflect the morphology of the different units but current methods of recording field systems needs to be more detailed and comprehensive before a functional classification can be produced. The Level 1 method of soil micromorphological description provides an efficient and accurate method of describing a large number of slides. No relationship between the form and function of the field units within each system was found using the available survey data and soil micromorphological evidence. The identified micromorphological evidence for past anthropogenic activity is associated with manuring practises rather than cultivation techniques.
86

Boro em trevo: eficiência de extratores e efeito sobre atributos químicos do solo, em área com e sem corte da parte áerea submetida a níveis de b

Batista, Cíntia Boeira January 2011 (has links)
Recentemente pesquisas têm se voltado à importância dos micronutrientes na nutrição mineral de plantas. Entretanto, há uma enorme dificuldade na quantificação de micronutrientes pela análise química do solo devido à baixa confiabilidade dos métodos. Muitos extratores utilizados pelos laboratórios de análises não possuem uma satisfatória correlação com as quantidades encontradas nas análises de foliar. Este estudo, além de avaliar extratores de solo para B, buscou igualmente avaliar o efeito do manejo do corte e remoção da parte aérea do trevo branco (Trifolium repens L.) sobre as características químicas do solo. Assim, este trabalho pretende: 1º- estudar a eficiência de soluções extratoras compostas por sulfato de alumínio, água quente, sorbitol e Mehlich1 na avaliação quantitativa de boro no solo e a eficiência dos extratores quando correlacionados com os resultados de boro foliar contido na cultura de trevo branco 2º- avaliar a influência do manejo de corte e remoção da parte aérea do trevo branco sobre as características químicas do solo. À campo o trevo-branco foi conduzido na Estação Experimental do Instituto Agronômico do Paraná – IAPAR, localizada no Município de Pato Branco – PR. A área experimental está localizada na região fisiográfica denominada Terceiro Planalto Paranaense. O solo é classificado como LATOSSOLO VERMELHO distroférrico relevo ondulado textura argilosa (EMBRAPA, 2008). O delineamento experimental foi blocos ao acaso com quatro repetições, sendo as parcelas constituídas de quatro coletas, as sub parcelas foram os tratamentos com doses crescentes de boro (0; 0,5; 1; 2 e 4 kg ha-1) na forma de ulexita (10% de B). As sub – sub parcelas foram as diferentes profundidades de solo avaliadas (0–5; 5–10 e 10- 20 cm). As amostras de solo e planta foram coletadas bimestralmente sendo que a planta foi enviada para o Laboratório do IAPAR em Londrina para determinação de teores de boro foliar. Enquanto que, as amostras de solo foram analisadas no Laboratório de Solos da UTFPR – Câmpus Pato Branco. Para a avaliação do segundo experimento foi utilizado delineamento de blocos ao acaso subdivididas com quatro repetições. O tratamento do manejo de corte e sem o corte da parte aérea do trevo branco foi considerado como a parcela e que teve como sub – parcela o tratamento de cinco doses de B (0, 0,5;1,0;2,0 e 4,0 kg ha-1, utilizando solução de Ulexita 10% B) e as sub – sub - parcelas foram constituídas pelas profundidades de amostragem de solo (0-5; 5-10 e 10-20 cm ). As metodologias utilizadas para as análises químicas de rotina do solo seguem Manual de Análise Química de Solo e Controle de Qualidade do IAPAR (1992), para as análises de extração e quantificação de B no solo e na planta utilizou-se EMBRAPA (2009). Com a primeira avaliação constata-se que o Al2(SO4)3 0,005M foi o extrator que apresentou maiores valores de correlação entre os valores do nutriente na planta com o valores do mesmo no solo de 0,92. Verificou-se que a Ulexita apresenta uma liberação lenta do nutriente B no solo sendo que os maiores teores de recuperação de B no solo pelos diversos extratores foram observados, em geral, após seis meses de aplicação. Na segunda avaliação verifica-se que a remoção constante da parte aérea de forrageiras provoca acidificação do solo e maior extração de bases, sendo assim, sistemas de produção de silagem e de feno devem constantemente repor bases ao solo via calagem. / Recently studies have been directed to the importance of micronutrients in plant mineral nutrition. However, there is great difficulty in quantifying micronutrients by chemical analysis of soil due to low reliability of the methods. Extractors used by many laboratories do not have a satisfactory correlation with the amounts found in the analysis of leaf. This study, besides evaluating extractors for soil B, also sought to evaluate the effect of handling the cutting and removal of the aerial part of white clover (Trifolium repens L.) on soil chemical properties. This work aims to: 1ª - to study the efficiency of extraction solutions consisting of aluminum sulfate, sorbitol and Mehlich1 the quantitative assessment of boron in soil and efficiency of extractors when correlated with the results of boron leaf contained in the culture of white clover 2ª - evaluate the influence of the management of cutting and removing the aerial part of white clover on soil chemical properties. In the field the white clover was conducted at the Experimental Station of the Agronomic Institute of Paraná - IAPAR, located in the city of Pato Branco - PR. The experimental area is located in the physiographic region called the Third Paranaense Plateau. The soil is classified as Oxisol clayey wavy relief (EMBRAPA, 2008). The experimental design was randomized blocks with four replications, and plots consist of four collections, the sub plots were the treatments with increasing doses of boron (0, 0.5, 1, 2 and 4 kg ha-1) in the form of ulexite (10% of B). The sub - sub plots were the different soil depths evaluated (0-5, 5-10, 10-20 cm). The soil and plant samples were collected every two months that the plant was being sent to the Laboratory in Londrina IAPAR to determine levels of boron leaf. While the soil samples were analyzed at the Laboratory of Soil UTFPR - Campus White Duck. To evaluate the second experiment was used a randomized block design with four replications subdivided. The samples were treated as two parts, sub-plots were cut and management without cutting the shoots of white clover, sub plots were treated as five doses of B (0, 0.5, 1.0 , 2.0 and 4.0 kg ha-1, using 10% solution Ulexite B) and sub - sub - plots were set up by soil sampling depths (0-5, 5-10 and 10-20 cm). The methodologies used for routine chemical analysis of soil following IAPAR (1992), as well as the analysis of extraction and quantification of B in soil and plant. With the first evaluation finds that the Al 2 (SO4) 3 0.005 M was the extractor that presented higher correlation values between the values of the nutrient in the plant with the same values in the soil of 0.92. It was found that the Ulexite has a slow release of nutrients in the soil B with the highest levels of recovery of B in the soil by different extractants were observed, usually after six months of application. In the second evaluation verifies that the constant removal of the aerial parts of forage causes soil acidification, an increase of toxic elements such as Al and extraction of bases, so production systems of silage and hay must constantly replenish the soil bases through liming.
87

Fluxos de nutrientes em propriedade rurais na região semiárida no Brasil / Nutrient fluxes in rural properties in the region semiarid of Brazil

Camelo, Germana Gomes dos Santos January 2015 (has links)
CAMELO, Germana Gomes dos Santos. Fluxos de nutrientes em propriedade rurais na região semiárida no Brasil. 2015. 60 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Ciências dos Solo, programa de Pós-Graduação em Agronomia - Solos e Nutrição de Plantas, Fortaleza-Ce, 2015 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-05-23T13:03:58Z No. of bitstreams: 1 2015_dis_ggscamelo.pdf: 1721445 bytes, checksum: 0db407705a8b9b66629406efb12352c1 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-05-23T13:04:15Z (GMT) No. of bitstreams: 1 2015_dis_ggscamelo.pdf: 1721445 bytes, checksum: 0db407705a8b9b66629406efb12352c1 (MD5) / Made available in DSpace on 2016-05-23T13:04:15Z (GMT). No. of bitstreams: 1 2015_dis_ggscamelo.pdf: 1721445 bytes, checksum: 0db407705a8b9b66629406efb12352c1 (MD5) Previous issue date: 2015 / The main sources of nutrients used in agriculture come from the exploitation of mineral reserves of nutrients or fossil fuels, both non-renewable and finite resources. Higher effectiveness in nutrient cycling increases the efficiency of nutrients use, decreasing the dependence on external inputs and increasing the sustainability of the farm system. The objective of present study was to quantify nutrient fluxes in farm systems, enabling the establishment of management strategies to allow P and K cycling in agricultural production systems. The study was conducted at municipality of Redenção, Ceará State, Brazil, through interviews with selected farmers, according to the local predominance. The farm was considered as a system composed by processes of human consumption, plant and animal production. Farm systems were classified into typology A and B based on the degree of diversity and interaction between processes. Evaluated material flows were mainly composed by animal food and agricultural inputs and goods and waste outputs in each process. The flow of nutrients was calculated from the material flows and the mineral content in each material, obtained from literature review. Error propagation and nutrient flows representation were carried out using the software STAN. Soil samples were collected to determine P and K stock in a chronosequence of cashew production processes with 0, 6, 7, 8 and 13 years old, with purpose to associate nutrient flows to the variation in nutrient soil stocks over time. Large amounts of P were added to the systems by use of organic fertilizers, resulting in a low efficiency of using of this nutrient. The production of cassava proved main drain system K, and therefore the survey and analysis of waste produced in the cassava processing may be the next step to identify strategies to enable K cycling. It was not possible to identify any nutrient cycling in the evaluated systems. The different degree of diversity and interactions between activities were restricted to flows from crop to animal production. / As principais fontes de nutrientes utilizadas na agricultura proveem da exploração de reservas minerais de nutrientes ou combustíveis fósseis, ambos recursos não renováveis e finitos. A maior eficácia na ciclagem de nutrientes por ciclos internos e externos às propriedades agrícolas aumenta a eficiência de utilização dos nutrientes na propriedade diminuindo a dependência de insumos externos e consequentemente a sustentabilidade da produção agrícola. Objetivou-se pelo presente estudo quantificar fluxos de nutrientes em propriedades rurais, possibilitando o reconhecimento estratégias de gestão capazes de viabilizar a ciclagem de P e K em sistemas agrícolas de produção. O estudo foi conduzido no município de Redenção, através de entrevistas à produtores rurais selecionados de acordo com a representatividade local e predominância na região semiárida. A propriedade rural foi considerada como um sistema constituído por processos de produção vegetal, animal e de consumo, classificadas em tipologias, C e D com base no grau de diversidade e interação nos processos de produção animal e vegetal. A determinação dos fluxos de materiais foi realizada por levantamento da entrada de alimentos e insumos para a produção agrícola e pecuária e saída de produtos ou resíduos em cada processo. O fluxo de nutrientes foi determinado a partir dos fluxos de materiais e o teor de minerais em cada material, obtido a partir de revisão bibliográfica. A propagação de erros envolvidos e o mapeamento dos fluxos de nutrientes foi realizada através do programa computacional STAN. Foram coletadas amostras de solo para a determinação do estoque de P e K em uma cronossequência de processos de produção de caju com 0, 6, 7, 8 e 13 anos de idade de produtores pertencentes à tipologia C, com propósito de relacionar o os fluxos de nutrientes com a variação nos estoques ao longo do tempo. O P vem sendo aplicado em quantidades elevadas por meio de fertilizantes orgânicos no sistema, resultando em uma baixa eficiência da utilização do mesmo. A produção de mandioca revelou-se como principal dreno de K do sistema, sendo, portanto, o levantamento e análise dos resíduos produzidos no processamento da mesma o próximo passo para identificar estratégias para possibilitar os ciclos alimentares de K. O mapeamento dos fluxos não identificou nenhuma ciclagem de nutrientes. O diferente grau de diversidade e interações entre as atividades restringiram-se a fluxos gerados a partir da produção vegetal para a produção animal.
88

Manejo de alturas da pastagem de aveia preta mais azevém e uso de suplementação para cabras pré e pós parto

Moro, Valério 20 December 2010 (has links)
O experimento foi conduzido na área experimental do IAPAR (Instituto Agronômico do Paraná) em Pato Branco - PR, de abril a outubro de 2009 para avaliar duas alturas da pastagem (12 e 21 cm) associadas ou não com suplementação energética (0,0 e 1,5% PV), em esquema fatorial 2x2, em blocos casualizados com três repetições. Os animais foram 36 cabras boer (55 kg de peso inicial) no estágio fisiológico de pré e pós parto, em pastagem de aveia (Avena strigosa Schreb) mais azevém (Lolium multiflorum Lam). A pastagem foi manejada sob lotação contínua e taxa de lotação variável para manter as alturas pretendidas para cada intensidade de pastejo. Foi avaliado o comportamento dos nutrientes no solo e de alguns atributos químicos em três profundidades amostradas (0-5, 5-10, 10-20 cm). Atributos químicos como pH-CaCl2, saturação de alumínio, soma de bases e saturação de bases, bem como alguns macro e micronutrientes, como potássio, magnésio, fósforo, ferro, manganês, cobre e zinco tiveram efeito apenas da profundidade amostrada. Conclui-se que manejando a pastagem a 12 cm com uso de suplementação, evita-se o aumento de teores de alumínio trocável em profundidade, assim como, aumentou os teores de Ca, o que minimiza problemas de degradação química do solo nas áreas de pastejo. A taxa média de acúmulo da forragem foi de 60 kg MS.ha־¹.dia־¹ e a produção total obtida em 180 dias foi 10.283 kg MS.ha־¹. A oferta de forragem foi influenciada pelas interações entre período e altura da pastagem, período e suplemento, assim como suplemento e altura da pastagem. A oferta média de forragem foi 8,32 e 4,30 kg MS.100-1 kg de PV na altura de 21 e 12 cm da pastagem, respectivamente. A carga animal total teve efeito da suplementação, sendo obtido 3.433 e 1.789 kg PVha-1dia-1 com e sem suplementação, respectivamente. Tanto o ganho médio diário como ganho por área foram negativos. O escore de condição corporal das cabras foi influenciado pelos tratamentos, com menores perdas na pastagem conduzida a 21 cm e com suplementação. O peso ao nascer dos cabritos não teve influencia dos tratamentos, nem do sexo. Cabritos acompanhados de suas mães na ausência de suplemento pastejaram 57,76% do tempo das mães, e com isso obtiveram melhor desempenho a partir de 25 dias de idade. O tempo de pastejo das cabras foi maior na ausência de suplementação, enquanto, o tempo de ócio foi maior nas cabras suplementadas. / The trial was carried out at IAPAR (Instituto Agronômico do Paraná) in Pato Branco - PR, from April to October 2009 to evaluate two canopy height (12 and 21 cm) either associated or not with energetic supplementation. It was compared two grazing intensities associated or not with energetic supplementation (0.0 e 1.5% of body weight - BW) in 2x2 split-plot design in Completely randomized blocks and three replicates. There were evaluated 36 boer breed goats (55 kg of initial weight) during either pre and pos lambing on black oat (Avena strigosa Schreb) plus annual ryegrass (Lolium multiflorum Lam) pasture. The pastures were continuously stocked using the put and take technique to maintain the height target to each grazing intensity. It was evaluated nutrients and chemical compound dynamic into three depths soil (0-5, 5-10, 10-20 cm). pH-CaCl2, Al saturation, sum of cation, cation saturation, likewise some macro and micronutrients (K, Mg, P, Fe, Mn, Cu, and Zn) were influenced just by sample depth. It can be concluded that 12 cm canopy height plus supplementation, the increase of exchangeable Al can be avoided at deep. As well as, Ca concentration in the soil was increased, which minimize chemical degradation of the soil in grazing lands. Forage accumulation rate was 60 kg DM.ha־¹.day־¹ and 10,283 kg DM.ha־¹ of total forage production was obtained whithin 180 days. Herbage allowance was influenced by period * height, period * supplementation, and supplementation * height interactions. Average herbage allowance was 8.32 and 4.30 kg MS.100-1 kg of BW for 21 and 12 cm of canopy height, respectively. Supplementation affected stocking rate which values were 3,433 and 1,789 kg BW.ha-1day-1 in presence and absence of supplementation, respectively. Average daily weight gain and gain per area were negative. Goat body condition score was affected by treatments, lesser body weight loss was verified in the 21 cm canopy height plus supplementation. Birth weight of kids had no effect neither treatments nor sex. Kids accompanied for their mothers without supplementation grazed 57.76% of grazing time of the goats, and performed better since 25 days old. Goat grazing time was higher in no supplementation treatments, whereas idling time was higher for goats supplemented.
89

Avaliação de doses da matriz fertilizante MBR no desenvolvimento inicial e na produção de frutas de ameixeira cultivar Irati

Denardi, Tadeu 24 February 2012 (has links)
Poucos trabalhos avaliam fontes orgânicas, pós de rochas e plantas de cobertura como fornecedoras de nutrientes para as plantas cultivadas. Neste contexto, o objetivo do trabalho foi avaliar doses da matriz fertilizante MBR no cultivo de ameixeira, cultivar Irati. O trabalho foi desenvolvido na área experimental da Universidade Tecnológica Federal do Paraná – Câmpus Pato Branco, no período de novembro de 2009 a dezembro de 2011. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições e três plantas úteis por parcela. Os tratamentos foram compostos de: testemunha absoluta (sem adubação), testemunha padrão (adubação integral 3/3), 2/3 da adubação integral associada a 0 kg ha-1 de MBR, 2/3 da adubação integral associada a 500 kg ha-1 de MBR, 2/3 da adubação integral associada a 1000 kg ha-1 de MBR e 2/3 da adubação integral associada a 2000 kg ha-1 de MBR. Foram avaliados, teores de nutrientes do solo, atividade microbiana, teor de nutrientes nas folhas e frutos, análise de frutos na colheita e pós-colheita e análise da produção e desenvolvimento das plantas. Os resultados obtidos através da análise química de solo mostraram que: a) os teores de potássio não se alteraram significativamente evidenciando um efeito positivo do fertilizante, provavelmente devido à menor lixiviação; e b) os teores de fósforo não sofreram alterações, no entanto foi possível observar um efeito positivo e este efeito pode estar associado à capacidade do silício competir com o fósforo pelos mesmos sítios de ligação e consequentemente reduzir a adsorção do fósforo. A atividade microbiana não foi influenciada positivamente ou negativamente pela utilização da matriz de fertilizantes. Os teores de nutrientes nas folhas e frutos também não sofreram alterações significativas. Com relação às análises de colheita e pós-colheita não foram observadas alterações significativas e os mesmos resultados foram obtidos para as análises de produção e desenvolvimento das plantas. Em geral, os resultados obtidos até agora não indicam potencial de utilização da matriz de fertilizante MBR na redução de 1/3 da adubação fosfatada e potássica na cultura da amexeira, cultivar Irati. / Few studies have evaluated organic sources, rock pownders and plants used to cover soil as resources that can provide nutrients to plants. In this context, the aim of this work was to evaluate some doses of matrix MBR fertilizer in the plum culture, cultivar Irati. The work was carried out in the experimental field of Federal Technological University of Paraná – Câmpus Pato Branco from November 2009 to December 2011. The experimental used design was made by chance in blocks with four repetitions and three useful plants by part. Treatments were composed by: one absolute untreated plant (without fertilization), pattern treated plant (complete fertilization 3/3), 2/3 of complete fertilizer associated to 0 kg ha-1 of MBR, 2/3 from complete fertilization associated to 500 kg ha-1 of MBR, 2/3 from complete fertilization associated to 1000 kg ha-1 of MBR and 2/3 from complete fertilization associated to 2000 kg ha-1 of MBR. Quantities of soil nutrients, microbial activity and quantities of nutrients in the leaf plant were analyzed and evaluated. The obtained results from the chemistry soil analysis have shown that: a) quantities of potassium did not change meaningfully which puts in evidence the fertilizer positive effect, probably due to lower leaching process; and b) quantities of phosphorus did not suffer changes, meanwhile it was possible to observe a positive effect and this effect can be associated to the silicon capacity to compete with phosphorus by the same linking sites and consequently to reduce phosphorous adsorption. Microbial activity was not positively or negatively influenced by the use of the matrix fertilizers. Quantities of nutrients in the leaves also did not suffer meaningful changes, with emphasis to quantities of potassium which maintained their own level. In relation to the harvest and post-harvest analyses, it was not noted meaningful changes and the same results were obtained to the production and development analyses of the plants. In general, the updating results indicate a no potential use of fertilizer matrix MBR in the reduction of 1/3 of phosphorous fertilization in the plum culture Irati.
90

Produção de alfafa e teor de boro e nitrogênio na planta e em solo submetido a níveis de boro

Borba, Tatiana Caldas 08 May 2012 (has links)
Fundação Araucária / O objetivo deste trabalho foi de avaliar o efeito de datas de coletas e doses de boro nas produções de matéria seca da parte aérea e raízes de alfafa, e os teores de boro e nitrogênio nas plantas e em um Latossolo no Sudoeste do Paraná. O experimento foi conduzido no IAPAR de Pato Branco, PR no ano agrícola de 2011. O delineamento experimental para produção de matéria seca de plantas de alfafa foi de blocos ao acaso com parcelas sub-divididas, com datas de coletas e doses de boro. Para avaliação da matéria seca de raiz (MSR) o delineamento foi de blocos ao acaso com quatro repetições, sendo os tratamentos cinco doses de boro. Para o solo o delineamento foi de blocos aos acaso com parcelas sub-subdivididas com quatro repetições. Onde as parcelas principais se constituíram de coletas, nas subparcelas, cinco doses de boro (0; 0,5; 1; 2; 4 kg ha-1) e nas sub-subparcelas as profundidades (0-5; 5-10 e 10-20cm). A maior produção de matéria seca avaliada por coletas foi encontrada no mês de outubro de 2011, com uma produção de 3.676,6 kg ha-1 e 131,31 kg ha-1 dia-1, respectivamente para matéria seca e taxa de acúmulo. Com relação as concentrações de nutrientes nas plantas as maiores médias foram encontradas nos meses de janeiro, com 81,37 mg kg-1 para boro e em outubro para o nitrogênio com 44,39 mg kg-1. A produção de matéria seca de raízes não foi influenciada pelas doses de boro. A maior concentração, em média, de boro no solo foi de 0,17 mg kg-1. Para o amônio obteve-se os maiores valores de 51,13 mg de NH4 kg-1, em média, no solo na terceira coleta. A máxima eficiência técnica para o nitrato foi com a dose de 2,14 kg de B ha-1, alcançando 52,33 mg kg-1. Além de ter sofrido efeito da interação entre datas de coletas e profundidade variando de 39 a 54 mg kg-1. / The aim of this study was to evaluate the effect of the rates of boron on dry matter production of Alfalfa plants and their roots, and boron and nitrogen concentration in plants in an Oxisol in Paraná, Brazil. The experiment was conducted at Agronomic Institute of Paraná (IAPAR) in Pato Branco town, Paraná, Brazil, in the 2011 agricultural year. The experimental design to the Alfalfa dry matter production was randomized blocks, in subdivided plots, with collection dates and boron doses. To the analysis of root dry matter (RDM) the design a randomized block design was used with four replicates, and treatments of five doses of boron. For the soil the design was randomized block with the sub-divided plots with four replications. In which the main plots consisted of collections, five doses of B (0, 0.5, 1, 2, 4 kg ha-1) in the subplots and in the sub-subplots at 0-5, 5-10 and 10-20 cm depths. The largest dry matter production evaluated by sampling occurred in October 2011, with a production of 3.676,6 kg ha-1 and 131,31 kg ha-1 day-1, for dry matter and accumulation rate, respectively. In relation to the nutrients concentration in plants the highest average was found in January, with 81,37 mg kg-1 of boron concentration, and 44,39 mg kg- 1 of nitrogen, in October. The dry matter production of roots was not affected by boron levels. The highest average boron concentration at the soil was 0,17 mg kg-1. The highest average ammonia levels was 51.13 mg kg-1 of NH4 at the soil in the third collect. The most efficient technique for the nitrate was a dose of 2,14 kg of B ha-1, reaching 52,33 mg kg-1. Besides, an interaction between date and depth was observed from 39 to 54 mg kg-1.

Page generated in 0.0544 seconds