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| Registros recuperados: 41 | |
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| Heck,R. J.; Tiessen,H.; Santos,M. C.; Salcedo,I. H.; Alves,R. J. T.. |
| This study compares the chemical composition of the solution and exchange complex of soil in a 3-year-old irrigated vineyard (Vitis vinifera L., Red Globe cultivar) with that of adjacent clearing in the native hyperxerophyllic 'caatinga' vegetation. The soils are classified as Plinthic Eutrophic Red-Yellow Argisol; according to Soil Taxonomy they are isohyperthermic Plinthustalfs. Detailed physiographic characterization revealed an impermeable gravel and cobble covering the crystalline rocks; the relief of this layer was more undulating than the level surface. Significant higher concentrations of extractable Na, K, Mg and Ca were observed within the vineyard. Lower soil acidity, higher Ca/Mg ratios, as well as lower sodium adsorption and Na/K ratios... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vineyard; Physiography; Moisture content; Exchangeable cations; Electrical conductivity; Soluble cations; Sodicity; Acidity. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832002000100020 |
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| Maia,Celsemy Eleutério; Rodrigues,Kelly Kaliane Rego da Paz. |
| One way of classifying water quality is by means of indices, in which a series of parameters analyzed are joined a single value, facilitating the interpretation of extensive lists of variables or indicators, underlying the classification of water quality. The objective of this study was to develop a statistically based index to classify water according to the Irrigation Water Quality Index (IWQI), to evaluate the ionic composition of water for use in irrigation and classify it by its source. For this purpose, the database generated during the Technology Generation and Adaptation (GAT) program was used, in which, as of 1988, water samples were collected monthly from water sources in the states of Paraíba, Rio Grande do Norte and Ceará. To evaluate water... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Salinity; Electrical conductivity; Ionic composition. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000300013 |
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| Carmo,Davi Lopes do; Silva,Carlos Alberto; Lima,José Maria de; Pinheiro,Gabriela Lúcia. |
| ABSTRACT Soil solution samplers may have the same working principle, but they differ in relation to chemical and physical characteristics, cost and handling, and these aspects exert influence on the chemical composition of the soil solution obtained. This study was carried out to evaluate, over time, the chemical composition of solutions extracted by Suolo Acqua, with the hydrophilic membrane (HM) as a standard, using soils with contrasting characteristics, and to determine the relationship between electrical conductivity (EC) and concentration of ions and pH of soil solution samples. This study was carried out under laboratory conditions, using three soils samples with different clay and organic matter (OM) contents. Soil solution contents of F−, Cl−,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electrical conductivity; Water soluble carbon; Soil liquid phase; Soil solution extraction methods. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100405 |
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| Machado,Flavia Cristina; Montanari,Rafael; Shiratsuchi,Luciano Shozo; Lovera,Lenon Henrique; Lima,Elizeu de Souza. |
| Brazilian soils have natural high chemical variability; thus, apparent electrical conductivity (ECa) can assist interpretation of crop yield variations. We aimed to select soil chemical properties with the best linear and spatial correlations to explain ECa variation in the soil using a Profiler sensor (EMP-400). The study was carried out in Sidrolândia, MS, Brazil. We analyzed the following variables: electrical conductivity - EC (2, 7, and 15 kHz), organic matter, available K, base saturation, and cation exchange capacity (CEC). Soil ECa was measured with the aid of an all-terrain vehicle, which crossed the entire area in strips spaced at 0.45 m. Soil samples were collected at the 0-20 cm depth with a total of 36 samples within about 70 ha. Classical... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Electrical conductivity; Management zones. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000401112 |
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| Fraga,Thiago Isquierdo; Carmona,Felipe de Campos; Anghinoni,Ibanor; Marcolin,Elio. |
| In the State of Rio Grande do Sul, Brazil, flooded rice fields using Patos Lagoon as the source of water for irrigation are subject to be damaged by salinity, since this source is bound to the sea on its southern end. The sensitivity of rice is variable during plant development, being higher in the seedling and reproductive periods. However, there is not enough information about the behavior of plants under salt stress during the course of its development, especially in the vegetative stage. This study evaluated the effect of different levels of salinity of irrigation water on the salinity of soil solution over time and on some plant attributes, during the vegetative stage of rice. The study was conducted in a greenhouse, where seeds of the variety IRGA... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electrical conductivity; Tillering; Vegetative growth; Oryza sativa L. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832010000400005 |
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| Menezes,Heitor R. de; Almeida,Brivaldo G. de; Almeida,Ceres D. G. C. de; Bennett,John M.; Silva,Emanuelle M. da; Freire,Maria B. G. dos S.. |
| ABSTRACT This research studied threshold electrolyte concentration (TEC) of irrigation water and its effect on the infiltration rate of two contrasting soils from Pernambuco state, Brazil. The experiment was conducted in the Soil Chemistry and Salinity Laboratory of Federal Rural University of Pernambuco. Each soil was packed in five Buchner funnels, where one funnel from each soil was submitted to treatment with solution of electrical conductivity (EC) of 0.5, 1.0, 2.0, 4.0 or 8.0 dS m-1. For each funnel containing soil, an increasing ratio of NaCl to CaCl2 was applied in a treatment solution to achieve 10 increasing values of sodium adsorption ratio (SAR) from 0 to 100. These solutions were applied through a Mariotte bottle, with a constant hydraulic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electrical conductivity; Saturated hydraulic conductivity; SAR. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662014001300053 |
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| Silva,Rodrigo J. da; Ferreira Junior,José M.; Silva,Flavia A.; Santos,Antonio C. M. dos; Lima,Saulo de O.; Silva,Rubens R. da. |
| ABSTRACT The development and survival of Eucalyptus urograndis plants may be influenced by products based on humic fractions of the organic matter, purified MAP and soil conditioners, such as hydrogel. Thus, the present study aimed to evaluate the effect of the commercial products Fertiactyl®, based on humic substances, purified MAP and hydrogel on the post-planting development and survival of Eucalyptus urograndis. The experiment was conducted in a randomized block design, with 25 treatments and four replicates, each of which consisted of 6 plants. The immersion of the tubes in solution with doses of Fertiactyl® and purified MAP promoted the increase in the development and survival of the plants. In the preparation of the hydrogel, the use of solution... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electrical conductivity; Hydration; Immersion. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000700625 |
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| Santana Júnior,Edvaldo B.; Coelho,Eugênio F.; Gonçalves,Karoline S.; Cruz,Jailson L.. |
| ABSTRACT The purpose of the study was to evaluate the effect of salinity levels of irrigation water on physiology and growth of banana cultivars during the vegetative stage. The experiment was carried out following a completely randomized design in split plots, with four levels of salinity in irrigation water (0.5, 2.0, 3.0 and 4.0 dS m-1) and four banana cultivars (Pacovan, Prata Anã, BRS Platina and Princesa) with three repetitions. Stomatal conductance, transpiration, relative water content, leaf water potential and proline concentration were evaluated at 150 days after transplanting (DAT), besides plant height, stem diameter and leaf area. All variables showed sensitivity to the increase of salinity level of irrigation water. The results of soil water... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Musa spp.; Relative transpiration; Electrical conductivity; Drip irrigation. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662020000200082 |
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| Lima,Nadielan da S.; Morais,Marciana B. de; Silva,Ênio F. de F. e; Camara,Terezinha R.; Willadino,Lilia. |
| ABSTRACT This study aimed to evaluate the effect of salt stress on production and antioxidative defense metabolism of two bell pepper cultivars (Capsicum annuum L.) grown hydroponically. The experimental design was in randomized blocks, with treatments arranged in a 5 x 2 factorial scheme with five replicates. The treatments consisted of five salinity levels of the nutrient solution (2.0, 3.5, 4.5, 5.5 and 6.5 dS m-1) with two bell pepper cultivars, ‘Bruno’ and ‘Rúbia’. Biomass and yield were reduced with increasing salinity. The contents of chlorophyll a, b and total decreased with increasing salinity. There was an increase in proline content and activity of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), showing the activation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electrical conductivity; Photosynthetic pigment; Antioxidant enzymes. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017001000675 |
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| Sousa,Alan B. O. de; Duarte,Sérgio N.; Sousa Neto,Osvaldo N. de; Souza,Ana C. M.; Sampaio,Pedro R. F.; Dias,Carlos T. dos S.. |
| ABSTRACT The purpose of this study was to evaluate the salt tolerance of mini watermelon (cv. Smile). The experiment was carried out in the greenhouse of the Department of Biosystems Engineering of ESALQ/USP. The experimental design was randomized blocks. The plants were irrigated with five levels of salinity (S1 = 1.0; S2 = 2.0; S3 = 3.0; S4 = 4.0 and S5 = 5.0 dS m-1). At 85 days after the beginning of the experiment, the plants and the physical and chemical variables of the fruit were evaluated. Salinity negatively affected the variables: length of the main stem, stem diameter, number of leaves, number of branches, leaf area, fresh and dry matter. Regarding the physical and chemical characteristics of fruits, salinity reduced the mass, diameter and the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Salt stress; Electrical conductivity; Cucurbitaceae. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016001000897 |
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| Ponciano,Isaac de M.; Miranda,Jarbas H. de; Cooke,Richard A.; Grah,Vanessa de F.; Silva,Alisson J. P. da. |
| ABSTRACT Despite the growing use of the time domain reflectometry (TDR) technique to monitoring ions in the soil solution, there are few studies that provide insight into measurement error. To overcome this lack of information, a methodology, based on the central limit theorem error, was used to quantify the uncertainty associated with using the technique to estimate potassium ion concentration in two soil types. Mathematical models based on electrical conductivity and soil moisture derived from TDR readings were used to estimate potassium concentration, and the results were compared to potassium concentration determined by flame spectrophotometry. It was possible to correct for random and systematic errors associated with TDR readings, significantly... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Central limit theorem; Instrumentation; Electrical conductivity. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000400343 |
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| Carneiro,Marcio A.; Lima,Augusto M. N.; Cavalcante,Ítalo H. L.; Cunha,Jailson C.; Rodrigues,Marcos S.; Lessa,Thiago B. da S.. |
| ABSTRACT Irrigated fruit crops have an important role in the economic and social aspects in the region of the Sub-middle São Francisco River Valley. Thus, the aim of this study was to evaluate soil salinity and the productive aspects of the mango crop, cv. Tommy Atkins, fertigated with doses of potassium chloride (KCl) and potassium sulfate (K2SO4) during two crop cycles (from January to March 2014 and from January to March 2015). The experiment was carried out in a strip-split-plot design and five potassium doses (50, 75, 100, 125 and 150% of the recommended dose) as plots and two potassium sources (KCl and K2SO4) as subplots, with four replicates. Soil electrical conductivity (EC), exchangeable sodium (Na+) and potassium (K+) contents and pH were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electrical conductivity; Plant nutrition; Mangifera indica L.; Semi-arid region. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000500310 |
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| Bezerra,Idelfonso L.; Nobre,Reginaldo G.; Gheyi,Hans R.; Souza,Leandro de P.; Pinheiro,Francisco W. A.; Lima,Geovani S. de. |
| ABSTRACT The aim of this study was to evaluate the growth of grafted guava cv. ‘Paluma’ subjected to different concentrations of salts in irrigation water and nitrogen (N) fertilization. The plants were transplanted to 150 L lysimeters and under field conditions at the Science and Agri-food Technology Center of the Federal University of Campina Grande, in the municipality of Pombal - PB. The experiment was conducted in randomized block design in a 5 x 4 factorial scheme, with three replicates, and the treatments corresponded to five levels of electrical conductivity of irrigation water - ECw (0.3; 1.1; 1.9; 2.7 and 3.5 dS m-1) and four N doses (70, 100, 130 and 160% of the N dose recommended for the crop). The doses equivalent to 100% corresponded to 541.1... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Psidium guajava L.; Electrical conductivity; Nitrogen. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000100032 |
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| Mantovani,José R.; Bernardes,Jéssica da S.; Landgraf,Paulo R. C.. |
| ABSTRACT In biodiesel production, vegetable press cake is obtained as waste, and a suitable destination for jatropha press cake would be the use in agriculture as organic fertilizer. This study aimed to evaluate the effect of jatropha press cake on soil fertility attributes and on lettuce production and accumulation of nutrients in the shoots. The experiment was conducted in pots in a greenhouse, in a randomized block design with eight treatments and five replicates. The treatments consisted of doses of jatropha press cake equivalent to 0, 0.5, 1.0, 2.0, 4.0, 8.0, 16.0 and 32.0 t ha-1. Portions of 5.5 dm3 of soil received limestone, phosphate fertilizer and the doses of jatropha press cake, and remained incubated for 30 days. After incubation, soil samples... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Organic waste; Organic fertilization; Nutrient; Electrical conductivity. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016001201089 |
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| Ferraz,Rener L. de S.; Magalhães,Ivomberg D.; Beltrão,Napoleão E. de M.; Melo,Alberto S. de; Brito Neto,Jósé F. de; Rocha,Maria do S.. |
| ABSTRACTThe castor bean crop plays an important social, environmental and economic role, especially due to possibility of its use as feedstock for the generation of clean energy. Thus, this study aimed to evaluate the contents of photosynthetic pigments, cell membrane extrusion and the relative water content in the leaves of the castor bean cultivar ‘BRS Energia’ under silicon and salinity levels. The experiment was carried out at Embrapa Cotton, in a completely randomized design, in a 4 x 4 factorial scheme, and the treatments consisted of four silicon levels (0, 100, 200 and 300 mg L-1) and four water salinity levels of (ECw 0, 2, 4 and 6 dS m-1), with three replicates. The gradual increase in salinity levels reduced the concentration of photosynthetic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ricinus communis L.; Chlorophyll; Electrolyte leakage; Electrical conductivity; Leaf fertilization. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662015000900841 |
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| Matias,Janete R.; Torres,Salvador B.; Leal,Caio C. P.; Leite,Moadir de S.; Carvalho,Sara M. C.. |
| ABSTRACT Sunflower is a species with multiple potentialities and its yield can be affected by the presence of soluble salts in the soil, which is common in arid, semi-arid and irrigated regions. The objective of this study was to evaluate the effect of hydropriming as inducer of salinity tolerance in seeds and seedlings of sunflower, hybrid MG305CP. The germination tests were set with four replicates of 50 seeds per treatment, maintained in germinator at 30 ºC for ten days. To simulate salinity, sodium chloride diluted in distilled water was used at electrical conductivities of 0 (control), 4, 8, 12 and 16 dS m-1. On the tenth day, the number of normal seedlings was counted and the length and dry matter of shoots and roots were determined. Seedling fresh... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Helianthus annuus; Asteraceae; Physiological conditioning; Abiotic stress; Electrical conductivity. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000400255 |
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| Vieira,R.D.; Minohara,L.; Carvalho,N.M. de; Bergamaschi,M.C.M.. |
| The relationship of black layer and milk line development on maize seed maturity was evaluated under tropical conditions. Seed moisture (g.kg-1), standard germination - SG (7 days, 25°C), and vigor, using accelerated aging-AA (96 hours, 42°C and 100% of RH), cold test-CT only in 1991/92 (7 days at 10°C and 7 days at 25°C) and electrical conductivity-EC (four 50-seed samples, 24 hours imbibition at 25°C) and milk line and black layer formation (using a five-stage rating system) were determined at 3 to 4 days intervals, using two genotypes (hybrid CX 133 and variety IAC 100) during the crop seasons of 1990/91 and 1991/92. The results showed that physiological maturity was reached before stage 4, based on seed germination and vigor (AA and CT) values, which... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Germination; Vigor; Accelerated aging; Cold test; Electrical conductivity. |
| Ano: 1995 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161995000100023 |
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| Soares,Frederico Antônio Loureiro; Gheyi,Hans Raj; Viana,Sergio Batista Assis; Uyeda,Claudio Augusto; Fernandes,Pedro Dantas. |
| Considering the lack of information on salt tolerance of passion fruit (Passiflora edulis) seedlings, a study was carried out to evaluate the effects of water salinity on the vigor and initial growth in a completely randomized design with 8 levels of electrical conductivity of irrigation water (ECw), varying from 1.0 to 8.0 dS m-1. Salinity delayed the germination process, but relative reduction was observed only above ECw 4.43 dS m-1. Seedling vigor and growth decreased with increasing salinity, however, water at 4 dS m-1 resulted in 85% of vigor and seedlings with more than 50% growth in comparison to the lowest salinity treatment. Based on soil salinity, the passion fruit may be considered as 'moderately tolerant' to salinity during the initial phase. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Passiflora edulis; Salinity tolerance; Electrical conductivity. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162002000300013 |
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| Oliveira,Itamar Pereira de; Asher,Colin J.; Edwards,David G.; Santos,Renato S. Mota dos. |
| Magnesium applications (MgS0(4).7H(2)0) to achieve 8 and 16 mmol c/cm3 of Mg (324 and 1284 kg of MgS0(4) ha-1) were made on one Ultisol from Australia Northeast to correct Mg deficiency in plants and to verify the optimum level of Mg to grow common bean (Phaseolus vulgaris L). Magnesium was applied together with lime, N, K, Cu, Zn, B, and Mo as calcium carbonate, ammonium nitrate, potassium phosphate, cupric and zinc sulphate, boric acid and sodium molybdate respectively a month before planting and P as phosphoric acid at the planting. The pH reached the equilibrium after six weeks of incubation. Higher electrical conductivity (EC) was observed in soil where Mg was applied to reach 8 mmol c/cm3 in the absence of common bean and 16 mmol c/cm3 when the plant... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Magnesium; Plant height; Soil pH; Electrical conductivity. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162000000100025 |
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| Carneiro,Paulo Torres; Fernandes,Pedro Dantas; Gheyi,Hans Raj; Soares,Frederico Antônio Loureiro; Viana,Sergio Batista Assis. |
| The cashew crop (Anacardium occiedentale L.) is of great economic and social importance for Northeast Brazil, a region usually affected by water and soil salinity. The present study was conducted in a greenhouse to evaluate the effects of four salinity levels established through electrical conductivity of irrigation water (ECw: 0.7, 1.4, 2.1 and 2.8 dS m-1, at 25ºC), on growth and physiological indexes of five rootstocks of dwarf-precocious cashew varieties CCP06, CCP09, CCP1001, EMBRAPA50, and EMBRAPA51. Plant height, leaf area, dry weight of root, shoot and total; water content of leaves, root/shoot ratio, leaf area ratio, absolute and relative growth rates and rate of net assimilation were evaluated. The majority of the evaluated variables were found to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anacardium occidentale; Electrical conductivity; Clones; Saline stress. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000100002 |
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| Registros recuperados: 41 | |
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