Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The use of direct seeding system brought changes on the weed management, by the mean of increasing of chemical control. The intense use of herbicides may have effect over the ecology of non-target soil organism. Two studies were conduct aiming testing the effect of herbicides over composition of soil mesofauna under genetically modified glyphosate resistance soy (RR®) (Chapter I) and assess the cito- genotoxicity effect of glyphosate, ammonium gluphosinate, paraquat and saflufenacil herbicide, applied during non-selective operation spray, before soy seeding (Chapter II). In Chapter I, results showed that in both agricultural years, soil mesofauna was dominate by Acari followed by Collembola, were Oribatida and Entomobryomorpha were the most predominating, respectively. In Chapter I, results showed of ammonium glufosinate favored an increase of springtails (Entomobryomorpha) and mites (Eupodes sp. Scheloribates sp. Galumnidae and Mesostigmata). Paraquat favored springtails (Entomobryomorpha) and mites (Pygmephoridae, Scheloribates sp. and Mesostigmata). Mite population (Pygmephoridae and Scheloribates sp.) increase with glyphosate treatment; and mites (Scheloribates sp.) with saflufenacil application; while in the glyphosate with saflufenacil association there was an increased springtails (Entomobryomorpha) density. The Haplotaxida Order show a greater sensitivity to glufosinato herbicides, paraquat and saflufenacil. In Chapter II, results showed that the glyphosate commercial formulation and analytical standard did not show cytotoxic effect at 5, 10 or 26ppm concentrations over the A. cepa cells; and only commercial formulation presented genotoxic. The gluphosinate shows no cytotoxic action, but tested plant cells, evidenced little genotoxic effect. Paraquat commercial formulation reduced cell division at the test concentrations (2, 4 and 11ppm) without genotoxic evidence. Saflufenacil did not affect cell division and express a weak genotoxicity using 0,25ppm concentration in plant cells test. / Com a introdução do sistema de plantio direto ocorreram mudanças no manejo de plantas daninhas, onde se intensificou o controle químico. O uso intenso de herbicidas pode ter efeito na ecologia de organismos não alvo presentes no solo. Nesse sentido foram conduzidos dois trabalhos objetivando avaliar o efeito de herbicidas sobre a composição da mesofauna edáfica em soja geneticamente modificada e resistência ao herbicida glifosato (soja RR®) (Capítulo I) e verificar o efeito citotóxico e de genotoxicidade de diferentes concentrações dos herbicidas glifosato, glufosinato, paraquat e saflufenacil, aplicados na operação de dessecação em pré-semeadura da soja RR® (Capítulo II). No capítulo I, os resultados mostraram que glufosinato favoreceu o aumento de colêmbolos (Entomobryomorpha) e ácaros (Eupodes sp. e Scheloribates sp. predadores Galumnidae e Mesostigmata). Paraquat favoreceu o aumento de colêmbolos (Entomobryomorpha) e ácaros (Pygmephoridae, Scheloribates sp. e Mesostigmata). A população dos ácaros (Pygmephoridae e Scheloribates sp.) aumentou com o tratamento glifosato; e dos ácaros (Scheloribates sp) com a aplicação de saflufenacil. Enquanto que na associação de glifosato com saflufenacil houve aumento da densidade de colêmbolos (Entomobryomorpha). A Ordem Haplotaxida apresentou maior sensibilidade aos herbicidas glufosinato, paraquat e saflufenacil. No capítulo II, os resultados mostraram que a formulação comercial e o padrão analítico do glifosato não apresentaram efeito citotóxico nas concentrações de 5, 10 ou 26ppm em células de Allium cepa; e apenas a formulação comercial apresentou ação genotóxica. O glufosinato não apresentou ação citotóxica, porém em células da planta teste se evidenciou pouca ação genotóxica. A formulação comercial de paraquat reduziu a divisão celular nas concentrações testadas (2, 4 e 11ppm), sem evidências de ação genotóxica. Saflufenacil não afetou a divisão celular e apresentou baixa ação genotóxica na concentração de 0,25ppm em células da planta teste.

As modificações ambientais provocadas pela humanidade, em especial pela agricultura, têm sido motivo de preocupação e estudos por todo o mundo. Nesse sentido, os solos figuram como um dos compartimentos ambientais mais impactados pelo uso de agrotóxicos, produtos amplamente utilizados na agricultura moderna. O objetivo deste trabalho foi avaliar se e como os agrotóxicos Score® 250 EC (i.a. difenoconazol) e Kraft® 36 EC (i.a. abamectina), isolados e em mistura, afetam a flora (germinação e crescimento do tomate - Lycopersicon lycopersicum), as comunidades microbianas do solo (biomassa microbiana em carbono, respiração, quociente metabólico e enzima β-glucosidase) e os enquitreídeos (reprodução de Enchytraeus crypticus em diferentes densidades e a relação trófica entre estes e os microrganismos), ao longo do tempo após a contaminação do solo. Em relação aos parâmetros microbianos, a despeito de algumas variações em decorrência da presença dos agrotóxicos, os indicadores das funções gerais do sistema edáfico não foram grandemente prejudicados, expressando uma redundância funcional. Não obstante, o solo-controle apresentou maior estabilidade em relação às variações dos parâmetros, sugerindo que os microrganismos presentes neste solo apresentaram uma maior robustez e estabilidade ao longo do tempo. Em relação aos testes com E. crypticus, os índices de reprodução não foram significativamente alterados em função da ação dos agrotóxicos, mas ratificou-se a importância dos microrganismos na dieta dos mesmos, haja vista as correlações entre o tamanho das comunidades microbianas e as taxas de crescimento dos enquitreídeos. Com relação ao crescimento e germinação do tomate, puderam ser observados valores maiores de altura e massa seca das plântulas em relação ao controle. Em contrapartida, observou-se uma possível melhor tendência de crescimento das plântulas no solo controle ao longo do tempo. Por fim, considerando a complexa problemática brasileira em relação ao uso de agrotóxicos, reiterou-se a importância do cumprimento das recomendações de aplicação de ambos os agrotóxicos avaliados por parte dos agricultores e recomendou-se a iniciativa de diminuição progressiva da sua utilização. / Environmental changes caused by humanity, especially by agriculture, have been a cause for concern throughout the world. The soils are one of the environmental compartments most impacted by the use of pesticides, which are widely used in modern agriculture. This research aimed at evaluating whether and how the insecticide Kraft® 36 EC (a.i. abamectin) and the fungicide Score® 250 EC (a.i. difenoconazole), isolated and in mixture, affect: a) the soil microbial communities (microbial biomass carbon, respiration, metabolic quotient and β-glucosidase enzyme); b) enchytraeid worms (reproduction of Enchytraeus crypticus in different densities and their trophic relation with microorganisms); and c) the flora (emergence and growth of tomato - Lycopersicon lycopersicum), over 84 days after contamination. The microbial indicators were not greatly impaired and expressed a functional redundancy, despite some variations due to the presence of pesticides. Nevertheless, the control group presented a greater stability than the contaminated ones, suggesting a greater robustness and stability of microorganisms over time, which are important factors for a better quality of the soil. In relation to E. crypticus tests, the importance of microorganisms on their diet was ratified, since positive correlations between the size of microbial communities and the enchytraeids rate of increase were observed. The different densities of E. crypticus were not significantly influenced by the effects of pesticides on the microorganisms. With respect to the growth and germination of tomato, higher values of height and dry mass of the seedlings were observed in contaminated groups. On the other hand, a higher growth tendency of the seedlings in the control soil was observed over time. Finally, considering the complexity of the Brazilian pesticide issue, we emphasize the importance of compliance of the recommendations on pesticides application and reinforce the initiative of decreasing their use.

No description available.

The overall aim of this thesis was to elucidate the relative importance of the bacterial and fungal energy channels within the soil food web and to differentiate and appreciate the differences in niche of the soil fauna when affected by differing land management. Feeding niche of the soil fauna is ambiguous and has been previously determined by observation, inference or biochemical studies. One method that can determine feeding preferences in situ is the use of stable isotopes. Stable isotopes trace the passage of C and N through different trophic levels, both at natural abundance and by the addition of a pulse of enrichment. The work described within this thesis describes the development of methods of culturing and labelling organisms for use in stable isotope studies. Bacteria, protozoa and fungi were cultured with stable isotopes enriched to 99 atom% and their growth and survival monitored. Utilising stable isotope enriched organisms means that empirical testing of the feeding interactions can occur and that differences between the bacterial and fungal energy channels can be explored. Two field sites were chosen to assess how management changes affect the food web, both sites were historically grassland with the same soil type, but one was converted to a willow woodland twenty years ago. The results of these studies have shown, at natural abundance a grassland and woodland habitat with very different stable isotope signatures, reflecting plant and soil composition, as well as differences in trophic niche and C drivers. The introduction of enriched bacteria illustrated that bacterial feeding was more widespread than normally portrayed in food web diagrams. The introduction of enriched protozoa highlighted that protozoan feeding by soil fauna was more prevalent in the grassland habitat; reflecting differences in linkages between trophic levels within the two habitats. Methods were also developed to “grow” enriched fungal hyphae back into soil food webs in a comparable way to the investigation of the bacterial energy channel. Different species of saprotrophic fungi were found to fractionate to differing extents when grown on the same natural abundance media and the fungus Absidia cylindrospora's growth was impacted when grown on a dually enriched medium. We can now infer that the bacterial energy channel is not as divergent from the fungal energy channel as previously hypothesised. The majority of soil fauna were found to be omnivorous through empirical results, consuming bacteria and protozoa, even when they were considered to be fungal feeders by the literature. The different habitats within the study were found to have different C drivers, with roots and soil being the primary driver in the grassland whilst litter was in the woodland, consequently favouring different food webs. This work makes a first step in measuring the contribution of the different feeding channels and feeding interactions occurring within the different trophic levels in the two habitats and shows the effect that one change in management has had over the entire faunal assemblage.

No description available.

Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2016-09-14T16:28:24Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese Derli.pdf: 4926019 bytes, checksum: 1b4daedf250fdbbebc74a91ffdb684aa (MD5) / Made available in DSpace on 2016-09-14T16:28:24Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese Derli.pdf: 4926019 bytes, checksum: 1b4daedf250fdbbebc74a91ffdb684aa (MD5) Previous issue date: 2015-08-14 / Sem bolsa / A região da campanha do Rio Grande do Sul é caracterizada por ter como matriz produtiva histórica a pecuária de corte, apresentando a figura do pecuarista familiar que tem na baixa produtividade da exploração pecuária seu principal sustento. O solo é a base produtiva para a atividade agropecuária, sendo preciso que se encontre mecanismos que levem a melhoria de suas propriedades naturais. Esse trabalho foi conduzido sobre solo coberto por vegetação campestre pertencente ao bioma pampa objetivando testar o efeito de dois sistemas de pastoreio com bovinos, pastoreio Contínuo e rotativo Voisin, na melhoria das condições de fertilidade deste solo, nas suas características químicas e biológicas, nas populações de ácaros e colêmbolos e na preservação das condições ambientais naturais. O presente experimento foi conduzido junto ao Campus Rural da Universidade da Região da Campanha, Campus Bagé-RS. O trabalho consistiu na utilização de dois tratamentos, representados pelo pastoreio de gado bovino em pastagem natural utilizando o sistema de pastoreio Voisin e o sistema de pastoreio Contínuo durante um período de três anos. O delineamento experimental foi o de blocos casualizados com repetições. As variáveis foram produção de esterco, pH em água, matéria orgânica, fósforo, potássio, cálcio, magnésio, alumínio, capacidade de troca de cátions, nitrogênio total, carbono orgânico, relação C/N, levantamento populacional da mesofauna (ácaros, colêmbolos e suas relações). A análise dos dados sugere que o pastoreio Voisin em relação ao Contínuo permite: aumentar a distribuição de dejeções bovinas por unidade de superfície pastoril; aumentar o ph e a CTC do solo; diminuir os teores de Al e de H+Al a partir do segundo ano; aumentar a partir do segundo ano a matéria orgânica, o potássio, o cálcio e o magnésio, e o fósforo a 7 partir o terceiro; aumentar os teores de nitrogênio e carbono orgânico; diminuir a relação carbono/nitrogênio; mais do que duplicar as comunidades de ácaros e colêmbolos. Ambos os sistemas de pastoreio não alteraram substancialmente os índices de diversidade, uniformidade e similaridade das populações de ácaros e colêmbolos. Observou-se que fósforo, potássio, cálcio e matéria orgânica aumentaram onde havia maiores populações de organismos do solo, condições estas encontradas no sistema de pastoreio Voisin. Concluiu-se que o sistema de pastoreio Voisin é uma ferramenta capaz de melhorar os atributos químicos e biológicos do solo favorecendo o pecuarista familiar. / The campaign region of Rio Grande do Sul is characterized by having as historical production matrix beef cattle, with the figure of the family farmer who has low productivity of livestock farming their main livelihood. The soil is the production base for agricultural activities, and must be located mechanisms that lead to improvement of its natural properties. This work was conducted on soil covered by grassland belonging to the pampa biome aiming to test the effect of two grazing systems with cattle, continuous and rotational grazing Voisin, improving fertility conditions of soil, its chemical and biological characteristics in populations mites and springtails and the preservation of natural environmental conditions. This experiment was conducted by the Rural Campus of the University of the Campaign Region, Campus Bagé-RS. The work involved the use of two treatments, represented by natural pasture in cattle grazing using the grazing system Voisin and continuous grazing system over a period of three years. The experimental design was a randomized block with repeats. Variables were producing manure, pH, organic matter, phosphorus, potassium, calcium, magnesium, aluminum, cation exchange capacity, total nitrogen, organic carbon, C/N, the population survey mesofauna (mites, springtails and their relations). Analysis of the data suggests that Voisin grazing on continuous allows: increase the 9 distribution of bovine stools per pasture surface unit; increasing the pH of soil and CTC; decrease the contents of Al and H+Al from the second year; increase from the second year organic matter, potassium, calcium and magnesium, and phosphorus from the third; increase the content of nitrogen and organic carbon; reduce the carbon/nitrogen ratio; more than double the communities of mites and springtails. Both grazing systems do not substantially alter the diversity indices, uniformity and similarity of populations of mites and springtails. It was observed that phosphorous, potassium, calcium and organic matter had increased where large populations of soil organisms found in these conditions Voisin grazing system. It was concluded that the Voisin grazing system is a tool to improve soil chemical and biological attributes favoring the family farmer

Platinum mining activities contribute substantially to South Africa's economy since it exceeded gold as economical contributor in 2001. Mining activities contribute to large amounts of waste production in the form of tailings and rock waste, deposited in the surrounding environment of the mine premises. Mining companies are held responsible for damages caused to the surrounding environment. These companies are required to introduce the cost of ecological rehabilitation in their operation costs as well as compile an environmental management plan. Numerous attempts to rehabilitate mine waste have proven unsuccessful. New and improved rehabilitation techniques are required to facilitate in the rehabilitation of these mine spoils. Woodchip-vermicompost produced from platinum mining wastes (woodchips and sewage sludge) was used as an alternative amendment to inorganic fertilisers during the rehabilitation of platinum mine tailings. The effectiveness of the woodchip-vermicompost as an alternative amendment during the platinum mine tailings rehabilitation were monitored using different ecosystem components. A natural veldt in the vicinity of the mine area was randomly selected to serve as a reference site. These ecosystem components selected have previously been shown to be effective as indicators of ecosystem quality. The components selected for this study includes the use of microbial enzymatic activity, microbial community structure, nematode trophic structures, and other mesofaunal groups such as micro-arthropods. The physical and chemical properties of the platinum mine tailings and reference area as well as the vegetation cover of the platinum mine tailings were determined. Statistical and multivariate analyses were use to determine the correlation between the dependent microbial components and dominate independent chemical properties. Nematode trophic structure, Maturity Index, and Plant-Parasitic nematode Index were used to compare the two rehabilitation techniques in terms of nematodes as indicators. Microarthropods family structures were used to compare the two amendments in terms of diversity and abundance. Enzymatic activity was positively affected by the addition of woodchip-vermicompost, than in the sites treated with inorganic fertilisers. The microbial community structure showed no statistically significant (p < 0.05) differences between the two amendments. A higher abundance of nematodes especially plant-parasitic nematodes and bacterivorous nematodes were observed in the woodchip-vermicompost sites than in the inorganic fertilised sites. According to the Maturity Index, both amendments became more enriched during the study period, while the Plant-Parasitic nematode Index showed that the carrying capacity for plantparasitic nematodes on the woodchip-vermicompost sites increased while it decreased in the inorganic fertilised sites, which can be related to the decrease in vegetation cover on the inorganic fertilised sites. Both coloniser (Prostigmata) and persister (Cryptostigmata and Mesostigmata) groups of the micro-arthropods, as well as a higher diversity of micro-arthropods, were present on the woodchip-vermicompost sites whereas the inorganic fertilised sites showed only the presence of colonisers, with a decrease in diversity and abundance of micro-arthropods over the study. The colonisation of micro-arthropods may have been affected by the addition of woodchip-vermicompost and vegetation cover, which contribute to the establishment of suitable microhabitats for these soil biota. By intercorrelating the results, it may be concluded that the addition of woodchip-vermicompost may be an essential part of the rehabilitation process, by contributing to soil organic material to the ecosystem system, which may improve the recolonisation of soil biota and ecosystem processes. However further studies need to be conducted in order to determine the long-term sustainability of the woodchip-vermicompost in providing organic material and sustaining the ecosystem processes. The study also showed the necessity to integrate various ecosystem components when evaluating ecosystem development due to the unique role each component plays and the impact it may have on other components. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.

Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.

Platinum mining activities contribute substantially to South Africa's economy since it exceeded gold as economical contributor in 2001. Mining activities contribute to large amounts of waste production in the form of tailings and rock waste, deposited in the surrounding environment of the mine premises. Mining companies are held responsible for damages caused to the surrounding environment. These companies are required to introduce the cost of ecological rehabilitation in their operation costs as well as compile an environmental management plan. Numerous attempts to rehabilitate mine waste have proven unsuccessful. New and improved rehabilitation techniques are required to facilitate in the rehabilitation of these mine spoils. Woodchip-vermicompost produced from platinum mining wastes (woodchips and sewage sludge) was used as an alternative amendment to inorganic fertilisers during the rehabilitation of platinum mine tailings. The effectiveness of the woodchip-vermicompost as an alternative amendment during the platinum mine tailings rehabilitation were monitored using different ecosystem components. A natural veldt in the vicinity of the mine area was randomly selected to serve as a reference site. These ecosystem components selected have previously been shown to be effective as indicators of ecosystem quality. The components selected for this study includes the use of microbial enzymatic activity, microbial community structure, nematode trophic structures, and other mesofaunal groups such as micro-arthropods. The physical and chemical properties of the platinum mine tailings and reference area as well as the vegetation cover of the platinum mine tailings were determined. Statistical and multivariate analyses were use to determine the correlation between the dependent microbial components and dominate independent chemical properties. Nematode trophic structure, Maturity Index, and Plant-Parasitic nematode Index were used to compare the two rehabilitation techniques in terms of nematodes as indicators. Microarthropods family structures were used to compare the two amendments in terms of diversity and abundance. Enzymatic activity was positively affected by the addition of woodchip-vermicompost, than in the sites treated with inorganic fertilisers. The microbial community structure showed no statistically significant (p < 0.05) differences between the two amendments. A higher abundance of nematodes especially plant-parasitic nematodes and bacterivorous nematodes were observed in the woodchip-vermicompost sites than in the inorganic fertilised sites. According to the Maturity Index, both amendments became more enriched during the study period, while the Plant-Parasitic nematode Index showed that the carrying capacity for plantparasitic nematodes on the woodchip-vermicompost sites increased while it decreased in the inorganic fertilised sites, which can be related to the decrease in vegetation cover on the inorganic fertilised sites. Both coloniser (Prostigmata) and persister (Cryptostigmata and Mesostigmata) groups of the micro-arthropods, as well as a higher diversity of micro-arthropods, were present on the woodchip-vermicompost sites whereas the inorganic fertilised sites showed only the presence of colonisers, with a decrease in diversity and abundance of micro-arthropods over the study. The colonisation of micro-arthropods may have been affected by the addition of woodchip-vermicompost and vegetation cover, which contribute to the establishment of suitable microhabitats for these soil biota. By intercorrelating the results, it may be concluded that the addition of woodchip-vermicompost may be an essential part of the rehabilitation process, by contributing to soil organic material to the ecosystem system, which may improve the recolonisation of soil biota and ecosystem processes. However further studies need to be conducted in order to determine the long-term sustainability of the woodchip-vermicompost in providing organic material and sustaining the ecosystem processes. The study also showed the necessity to integrate various ecosystem components when evaluating ecosystem development due to the unique role each component plays and the impact it may have on other components. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.

No description available.