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| Medeiros,Wilker Nunes; Valente,Domingos Sárvio Magalhães; Queiroz,Daniel Marçal de; Pinto,Francisco de Assis de Carvalho; Assis,Igor Rodrigues de. |
| ABSTRACT Mapping the apparent soil electrical conductivity (ECa) has become important for the characterization of the soil variability in precision agriculture systems. Could the ECa be used to locate the soil sampling points for mapping the chemical and physical soil attributes? The objective of this work was to examine the relations between ECa and soil attributes in two fields presenting different soil textures. In each field, 50 sampling points were chosen using a path that presented a high variability of ECa obtained from a preliminary ECa map. At each sampling point, the ECa was measured in soil depths of 0-20, 0-40 and 0-60 cm. In addition, at each point, soil samples were collected for the determination of physical and chemical attributes in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Management zones; Soil sampling. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902018000100043 |
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| Melo,Roseli Freire; Dias,Luiz Eduardo; Assis,Igor Rodrigues de. |
| ABSTRACT Persistent areas of tailings and deposits from coal and gold mining may present high levels of arsenic (As), mainly in the arsenate form, endangering the environment and human health. The establishment of vegetation cover is a key step to reclaiming these environments. Thus, this study aimed to evaluate the potential of Eucalyptus urophylla and E. citriodora seedlings for use in phytoremediation programs of arsenate-contaminated areas. Soil samples were incubated at increasing rates (0, 50, 100, 200 and 400 mg dm-3) of arsenic (arsenate form, using Na2HAsO4) for 15 days. The seedlings were produced in a substrate (vermiculite + sawdust) and were transplanted to the pots with soil three months after seed germination. The values of plant height and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phytoremediation; Phytotoxicity; Revegetation. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100516 |
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| Assis,Igor Rodrigues de; Dias,Luiz Eduardo; Ribeiro Jr,Emerson Silva; Abrahão,Walter Antônio Pereira; Mello,Jaime Wilson Vargas de; Veloso,Renato Welmer. |
| Acid mine drainage (AMD) is an environmental concern due to the risk of element mobilization, including toxic elements, and inclusion in the food chain. In this study, three cover layers were tested to minimize As, Fe and S mobilization from a substrate from former gold mining, containing pyrite and arsenopyrite. For this purpose, different layers (capillary break, sealant and cover layer) above the substrate and the induction of a geochemical barrier (GB) were used to provide suitable conditions for adsorption and co-precipitation of the mobilized As. Thirteen treatments were established to evaluate the leaching of As, Fe and S from a substrate in lysimeters. The pH, As, Fe, S, Na, and K concentrations and total volume of the leachates were determined.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Jarosite; Arsenic; Cover layers; Gold mining; Rehabilitation. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000200036 |
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| Guimarães,Lorena Abdalla de Oliveira Prata; Dias,Luiz Eduardo; Rocha,Genelício Crusoé; Assis,Igor Rodrigues de; Fernandes,Raphael Bragança Alves. |
| ABSTRACT Tailings from bauxite washing produced in Porto Trombetas, Pará state, a Brazilian Amazon region, have chemical and physical characteristics limiting the development of plants, which hinders to revegetate the tanks where they are deposited. This study was carried out under field conditions, and aimed to assess the physical quality of these tailings after a decade of recovery practices. Three treatments were assessed: no application of inputs and planting of seedlings (T1) and two levels of fertilization, one with lower (T2) and other with higher (T3) doses of limestone and fertilizers associated with planting tree seedlings. After ten years of experimentation, penetration resistance (PR) and substrate moisture up to 60 cm depth were assessed and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Revegetation; Mining; Natural regeneration.. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902018000200192 |
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| Matsinhe,Daniel Zefanias; Pereira,Silvio Bueno; Oliveira,Rubens Alves de; Assis,Igor Rodrigues de; Oliveira,Reginaldo Miranda. |
| ABSTRACT Irrigation has a great importance in the production of food, and it is responsible for consuming a large part of the water used by human activities. This makes the rational management of water use fundamental for sustainable food production. For this purpose, the determination of bulk density is important and needs to be obtained with the simplest, least onerous methods possible, while maintaining precision and accuracy. Therefore, the objective of this work was to evaluate the use of PVC pipes of different dimensions to determine bulk density. For comparison purposes, the volumetric ring, paraffin clod, beaker and excavation methods were also used. Deformed and undisturbed soil samples of different granulometries were collected at the depths of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water use; Irrigated agriculture; Soil management. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902019000100027 |
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