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This study aimed to evaluate the occurrence of mycorrhizal fungi and glomalin content in soil under different cover crops with and without the application of nitrogen in the cover. The following cover plants were used: Crotalaria juncea (Crotalaria juncea L.), wild beans from Ceará (Canavalia brasiliensis Mart. ex Benth.), Guandú 'BRS mandarin' [Cajanus cajan (L.) Millsp.], millet 'BR05' [Pennisetum glaucum (L.) R.Br.] and sorghum 'BR 304' [Sorghum bicolor (L.) Moench]. The absolute control of the experiment was the treatment without the use of cover crops, that is, the vegetation of spontaneous occurrence in the area. The experimental design was randomized blocks in subplots with three replications. Spore density, mycorrhizal colonization rate, easily extractable glomalin, and species present in the rhizosphere of the cover crops were determined. No differences were found in the diversity of mycorrhizal fungi associated with the different cover crops studied or in the values of spore density, root colonization, or glomalin content. Nitrogen application did not influence the mycorrhizal activity in the investigated cover crops. The most frequent species associated with cover crops were Scutellospora pellucida and Scutellospora persica in C. juncea; Gigaspora sp. on Sorghum; Glomus macrocarpum in Guandu; G. macrocarpum and Glomus clavisporum in millet; and Glomus microaggregatum and Glomus tortuosum in Spontaneous Vegetation.
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Mining operations lead to the production of large quantities of mineral waste, such as fluid fine tailings whose disposal is rather challenging. In Brazil, tailings disposal is facing a critical situation due to the large accidents that took place in the last couple of years. As a response to these accidents, the Brazilian Mining Agency became stricter on licensing mining complexes and issued an interruption on activities on 56 tailings dams. In this paper, the authors propose a promising approach to minimize risks on the existing tailings dams hoping that the industry succeeds at mining avoiding social harms and environmental damages. The results presented herein showed that in situ electrical dewatering is a promising technology that offers many benefits. It can significantly increase the solids content of liquefiable tailings stratum within a short time. This leads to tailings masses possessing higher shear strength. As a consequence, this technology might well lead to safe tailing dams in Brazil bringing socio-economic and environmental benefits.
Assuntos
Mineração , BrasilRESUMO
The Cerrado is one of the most important regions for agricultural development in the world and is the main productive breadbasket of the Americas. One of the main agricultural activities in the region is high-tech livestock. Cerrado soils are predominantly low in fertility, and arbuscular mycorrhizal fungi play a fundamental role in plant nutrition in this biome. Understanding the behavior of mycorrhizal fungi in the soil under pasture is essential for the development of more efficient and sustainable management practices. Thus, this work aims to verify the activity of arbuscular mycorrhizal fungi in different species of forage grasses cultivated in cerrado soil. To measure mycorrhizal activity, soil spore density factors and mycorrhizal colonization rates in roots of 14 forage grass genotypes were investigated. No significant differences were identified in spore density values between the investigated genotypes. Panicum maximum cv and Mombasa showed the lowest values of mycorrhizal colonization, and the highest values were found in the roots of Brachiaria decumbens. Among the identified genera associated with the rhizosphere of the genotypes studied, Gigaspora, Scutelospora and Sclerocysts are less frequent, which indicates that the association with these fungal genera is less recurrent than with the others.
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Sugarcane is a very important economic crop that relies heavily on agricultural machinery, which contributes to soil compaction and a consequent decline in productivity. Subsoiling operation reduces the problems caused by compression; however, it is necessary to know its location and intensity. Accordingly, the aim of this work is to present a compression diagnostic method based on soil resistance to penetration as the parameter that indicates need for intervention in the subsoil. Measurements of penetration resistance was carried out in areas of sugarcane, located in the municipalities of Goianésia, Barro Alto and Santa Isabel, in the Brazilian state of Goiás. The Falker penetrometer (PLG 1020) was used, adjusted to a maximum depth of 40 cm and adopted as a critical resistance value of 4.0 MPa. The data were interpolated using kriging and adjusted in AutoCAD 2013 (Autodesk). The methodology proved effective in areas of compacted soil, and the surface layer had less resistance. The reduction in soil preparation was 96.54% and when considering the topographic adjustments, the reduction was 74.07%, showing the viability and importance of the diagnosis to show the proper management.
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Purpose: Understanding the dynamics of mycorrhizal fungi in the Cerrado is fundamental for the adoption of conservation practices and for understanding the resilience of this biome in relation to long periods of drought. Thus, this work aimed to verify the dynamics of the mycorrhizal population in five phytophysiognomies of the Cerrado biome. Methods: The samples were taken from the Chapada dos Veadeiros National Park, a permanent preservation with native Cerrado vegetation without any anthropic influence. The five main phytophysiognomies of the Cerrado biome were chosen: the Campo Limpo, Campo Sujo, Cerrado Strictu Sensu, Cerradão, and Veredas. Rhizospherical soil samples were collected in both the wet and dry seasons. Spore density, mycorrhizal colonization rate, easily extractable glomalin, and associated mycorrhizal fungi genera were identified. Results: The values of spore density, mycorrhizal colonization rate, and glomalin were higher in the samples performed during the dry season compared to the samples performed in the rainy season. The same behavior was observed when comparing the different phytophysionomies. Conclusion: Mycorrhizal activity is higher in dry periods when compared to rainy periods. There is no specificity of genera of arbuscular mycorrhizal fungi within the Cerrado phytophysiognomies.
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O objetivo deste trabalho foi avaliar os aspectos biológicos de C. flavipese sua marcação, além do desenvolvimento de uma metodologia para captura de adultos. Lagartas de D. saccharalis alimentadas com dieta artificial contendo os corantes SudanRed 7B e Solvent Blue 35 nas concentrações de 200 e 400 ppm, óleo vegetal a 200 e 400 ppm e sem óleo. Posteriormente, as lagartas foram parasitadas nos tratamentos supracitados. Avaliou-se o período entre o parasitismo e a emergência das larvas (ovo-larval), a empupação, o peso das massas e das pupas, razão sexual, longevidade dos adultos e marcação. Após a definição do corante/concentração adequado para marcar adultos de C. flavipes, avaliou-se a capacidade de dispersão e parasitismo das fêmeas adultas em condições de campo. Utilizou-se o teste de Dunnett para as variáveis relacionadas ao desenvolvimento de larvas, pupas e adultos de C. flavipes e o procedimento de GLM para análise de variância e o LSMEANS para ajustar as medias em cada fator testado. Definiu-se o corante SudanRed 7B na concentração de 200 ppm é o melhor corante/concentração para marcar o parasitoide larval C. flavipes, após desenvolvida a metodologia para captura de C. flavipes, que associadas à marcação, permitiram avaliar a capacidade de voo pela distância e captura desses indivíduos com precisão. Foi definida a armadilha de garrafa pet 600 como a melhor para...(AU)
The objective of this study was to evaluate the biological aspects of C. flavipes your markup, and the development of a methodology for adult capture. Sugarcane borers fed on artificial diet containing the dyes SudanRed 7B and Solvent Blue 35 in concentrations of 200 and 400 ppm, vegetable oil at 200 and 400 ppm and without oil. Later, the caterpillars were parasitized in the above treatments. Evaluated the period between parasitism and the emergence of the larvae (egg-larval), the pupation, the weight of the masses and pupae, sex ratio, adult longevity and marking. After the setting of the dye / marker suitable concentration for adult C. flavipes, we evaluated the dispersibility and parasitism of adult females under field conditions. We used the Dunnett test for the variables related to the development of larvae, pupae and adults of C. flavipes and the GLM procedure for analysis of variance and the LSMEANS to fit the media in each factor tested. Set up The SudanRed 7B dye at a concentration of 200 ppm is the best dye / concentration to mark the larval parasitoid C. flavipes after developed the methodology for capturing C. flavipes, which associated with marking, allowed evaluating the flight capacity by distance and capture these individuals accurately. It was defined bottle trap 600 as the best pet for evaluation capture and parasitism. The maximum flight distance field in...(AU)
Assuntos
Himenópteros/parasitologia , Doenças ParasitáriasRESUMO
O objetivo deste trabalho foi avaliar os aspectos biológicos de C. flavipese sua marcação, além do desenvolvimento de uma metodologia para captura de adultos. Lagartas de D. saccharalis alimentadas com dieta artificial contendo os corantes SudanRed 7B e Solvent Blue 35 nas concentrações de 200 e 400 ppm, óleo vegetal a 200 e 400 ppm e sem óleo. Posteriormente, as lagartas foram parasitadas nos tratamentos supracitados. Avaliou-se o período entre o parasitismo e a emergência das larvas (ovo-larval), a empupação, o peso das massas e das pupas, razão sexual, longevidade dos adultos e marcação. Após a definição do corante/concentração adequado para marcar adultos de C. flavipes, avaliou-se a capacidade de dispersão e parasitismo das fêmeas adultas em condições de campo. Utilizou-se o teste de Dunnett para as variáveis relacionadas ao desenvolvimento de larvas, pupas e adultos de C. flavipes e o procedimento de GLM para análise de variância e o LSMEANS para ajustar as medias em cada fator testado. Definiu-se o corante SudanRed 7B na concentração de 200 ppm é o melhor corante/concentração para marcar o parasitoide larval C. flavipes, após desenvolvida a metodologia para captura de C. flavipes, que associadas à marcação, permitiram avaliar a capacidade de voo pela distância e captura desses indivíduos com precisão. Foi definida a armadilha de garrafa pet 600 como a melhor para...
The objective of this study was to evaluate the biological aspects of C. flavipes your markup, and the development of a methodology for adult capture. Sugarcane borers fed on artificial diet containing the dyes SudanRed 7B and Solvent Blue 35 in concentrations of 200 and 400 ppm, vegetable oil at 200 and 400 ppm and without oil. Later, the caterpillars were parasitized in the above treatments. Evaluated the period between parasitism and the emergence of the larvae (egg-larval), the pupation, the weight of the masses and pupae, sex ratio, adult longevity and marking. After the setting of the dye / marker suitable concentration for adult C. flavipes, we evaluated the dispersibility and parasitism of adult females under field conditions. We used the Dunnett test for the variables related to the development of larvae, pupae and adults of C. flavipes and the GLM procedure for analysis of variance and the LSMEANS to fit the media in each factor tested. Set up The SudanRed 7B dye at a concentration of 200 ppm is the best dye / concentration to mark the larval parasitoid C. flavipes after developed the methodology for capturing C. flavipes, which associated with marking, allowed evaluating the flight capacity by distance and capture these individuals accurately. It was defined bottle trap 600 as the best pet for evaluation capture and parasitism. The maximum flight distance field in...
Assuntos
Doenças Parasitárias , Himenópteros/parasitologiaRESUMO
INTRODUCTION: Larva migrans visceral is caused by Toxocara sp and has never been studied in Bahia. This work investigated the prevalence and risk factors for infection by Toxocara canis in individuals from Salvador, State of Bahia. METHODS: Three hundred and thirty-eight individuals were investigated for the presence of serum IgG anti-T. canis. RESULTS: IgG anti-T. canis was higher in individuals from lower social classes who had more contact with dogs and cats, indicating that these variables are factors risk for this infection. CONCLUSIONS: The prevalence of T. canis infection was high. The risk factors for this infection identified are in agreement with in the literature.
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Anticorpos Anti-Helmínticos/sangue , Imunoglobulina G/sangue , Toxocara canis/imunologia , Toxocaríase/epidemiologia , Adolescente , Adulto , Animais , Brasil/epidemiologia , Gatos , Cães , Feminino , Humanos , Masculino , Prevalência , Fatores de Risco , Fatores Socioeconômicos , Toxocaríase/diagnóstico , Toxocaríase/transmissão , Adulto JovemRESUMO
INTRODUÇÃO: Larva migrans visceral é causada por Toxocara sp e nunca foi estudada na Bahia. Neste trabalho, investigou-se a prevalência e fatores de risco de infecção por Toxocara canis, em indivíduos de Salvador. MÉTODOS: Trezentos e trinta e oito indivíduos foram investigados para presença de anticorpos IgG séricos anti-T. canis. RESULTADOS: IgG anti-T. canis foi mais alta em indivíduos de classe social baixa com maior contato com cães e gatos, indicando que estas variáveis são fatores de risco para esta infecção. CONCLUSÕES: A prevalência de infecção por T. canis foi alta. Os fatores de risco desta infecção encontrados estão de acordo com a literatura.
INTRODUCTION: Larva migrans visceral is caused by Toxocara sp and has never been studied in Bahia. This work investigated the prevalence and risk factors for infection by Toxocara canis in individuals from Salvador, State of Bahia. METHODS: Three hundred and thirty-eight individuals were investigated for the presence of serum IgG anti-T. canis. RESULTS: IgG anti-T. canis was higher in individuals from lower social classes who had more contact with dogs and cats, indicating that these variables are factors risk for this infection. CONCLUSIONS: The prevalence of T. canis infection was high. The risk factors for this infection identified are in agreement with in the literature.