234 research outputs found

    Soil phosphorus fractions in a sandy typic hapludaft as affected by phosphorus fertilization and grapevine cultivation period.

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    The purpose of this study was to quantify the phosphorus (P) fractions in phosphate-fertilized sandy soils under grapevines. Soil was sampled from a grassland site and two vineyards (13 and 31 years old) in the State Rio Grande do Sul, Brazil, from the layers 0-5, 5-10, 10-15, 15-20, and 20-40 cm deep. The samples were prepared and P fractions were assessed by chemical fractionation. Phosphate fertilization of the vineyard soils increased P contents to a depth of 40 cm, especially in the more recalcitrant fractions but detectable in the more labile fractions as well, which are plant available and may increase the risk of environmental contamination. Phosphate fertilizers and the period of grapevine cultivation had little effect on the levels of organic P forms, whereas cover crops in vineyards could be an appropriate strategy to increase or maintain the levels of soil organic matter and the levels of organic P over the years

    Lixiviação e volatilização de nitrogênio em um Argissolo cultivado com videira submetida à adubação nitrogenada.

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    O nitrogênio (N) aplicado na superfície do solo em vinhedos pode ser perdido por volatilização ou lixiviação, sendo uma das possíveis explicações para o baixo aproveitamento de N pelas videiras. O trabalho objetivou avaliar as perdas de N por volatilização e lixiviação do N mineral em solo cultivado com videira submetida à adubação nitrogenada. Foram instalados dois experimentos em um vinhedo de Cabernet Sauvignon, em Rosário do Sul (RS), Brasil. No experimento 1, foram instalados lisímetros no solo que recebeu a aplicação de 0, 40, 80 e 120kg de N ha-1 ano-1 na forma de ureia e, durante o período de agosto a dezembro de 2009, foi coletada a solução do solo para a análise de N mineral. No experimento 2, foram instaladas câmaras coletoras no solo que recebeu, em agosto de 2010, a aplicação de 0, 20, 40, e 80kg de N ha-1 ano-1 na forma de ureia, 40kg de N ha-1 ano-1 de composto orgânico e 40kg de N ha-1 ano-1 de ureia revestida com polímeros, para avaliar a volatilização de N-NH3 do momento da aplicação até 80 horas depois da aplicação. As maiores concentrações de nitrogênio mineral na solução lixiviada foram encontradas nas doses mais elevadas de fertilizante mineral aplicado e ao longo da brotação e florescimento das videiras, o que pode diminuir o aproveitamento do nutriente pelas plantas. Os maiores fluxos e perdas de amônia do solo cultivado com videira para a atmosfera aconteceram nas doses mais elevadas de nitrogênio mineral aplicado, especialmente, depois de 44 horas da sua aplicação sobre a superfície do solo. A aplicação de ureia revestida com polímeros e composto orgânico promoveram as menores perdas de amônia por volatilização, o que pode estimular o aproveitamento de nitrogênio pelas videiras

    Iron fertilization to enhance tolerance mechanisms to copper toxicityof ryegrass plants used as cover crop in vineyards.

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    Ryegrass (Lolium perenneL.) is a plant species that can express mechanisms of tolerance to copper (Cu)toxicity. Therefore, the agronomical approach of intercropping system with ryegrass may represent apromising tool to limit the onset of Cu toxicity symptoms in the other intercropped plants species,particularly when an inadequate nutrient availability like iron (Fe) shortage is also concurrently present.This study aimed at assessing the mechanisms involved in the mitigation of Cu phytotoxicity and thestress effects on plant growth, root morphology and nutrition of ryegrass fertilized with two different Fesources. To this purpose, seedlings of ryegrass were hydroponically grown for 14 days in controlledconditions with 4 different levels of Cu (0.2, 5.0, 25 and 50mM) and with either 100mM Fe-EDDHA or Fe-EDTA. Results show that high levels of Cu availability enhanced the root content of organic anions as wellas the root exudation. Different Fe fertilizations at the condition of 50mM Cu induced changes in rootphenolic compounds, citrate and fumarate contents and the exudation pattern of phenolic compounds.Differences in plant growth were not observed between the two Fe sources, although Cu concentration inplant tissue fed with Fe-EDTA was lower in the condition of 50mM Cu. The enhanced root exudation ofCu-complexing organic compounds (including phenolics) in ryegrass plants when exposed to excessiveCu availability could be at the basis of the ameliorated edaphic rhizosphere conditions (lower Cuavailability). For this reason, from the agronomical point of view ryegrass plants used in intercroppingsystems with crops like vine plants could represent a promising strategy to control Cu toxicity invineyard soils. Further studies under thefield conditions must be taken to support presentfindings.©2019 Elsevier Ltd. All rights reserved

    Nitrogen fertilization of "Chardonnay" grapevines: yield, must composition and their relationship with temperature and rainfall.

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    In soils rich inorganic matter(OM), such as those in the elevations of South Brazil, themineralized N from organic matter does not always meet the N demands of grapevines, thus, N applications are necessary during vinegrowth. However, the optimal N rate to achieve satisfactory yield and desirable grape enological composition is not known

    Establishment of potassium reference values using Bayesian models in grapevines

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    Critical levels (CL) of available potassium (K) in soils and leaves and maximum technical efficiency (MTE) doses are relevant information to define the best K fertilization strategies. The aim of this study was to determine reference values of K in leaves and soil, using Bayesian analysis, in order to maximize grape yield and must quality of ‘Chardonnay’ and ‘Pinot Noir’ grown in a subtropical climate. The vines were subjected to applications of 0, 20, 40, 60 and 80 kg K2O ha−1 year−1. The CL and MTE doses of K, in leaves and soils, were determined using Bayesian hierarchical models. The range of probability of the occurrence of CL in leaves was 15.8 to 18.9 g K kg−1 in ‘Chardonnay’ and 16.8 to 19.1 g K kg−1 in ‘Pinot Noir’ at flowering. Moreover, the range was 15.3 to 18.1 g K kg−1 in ‘Chardonnay’ and 16.1 to 18.2 g K kg−1 in ‘Pinot Noir’ at veraison. In the soil, the CL of available K for ‘Chardonnay’ was 27.4 mg K kg−1 and for ‘Pinot Noir’ it was 23.2 mg K kg−1. The increase of K in leaves and soil increased the TSS, while the TTA decreased in both cultivars after sufficiency rate. The MTE was estimated in ‘Pinot Noir’. The proposition of CL and/or MTE doses of K can help increase the efficiency of K fertilization in vineyards

    Vitamin D3 as adjuvant in the treatment of type 2 diabetes mellitus: modulation of genomic and biochemical instability

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    Erratum in - Corrigendum: Vitamin D3 as adjuvant in the treatment of type 2 diabetes mellitus: modulation of genomic and biochemical instability. Fagundes GE, Macan TP, Rohr P, Damiani AP, Da Rocha FR, Pereira M, Longaretti LM, Vilela TC, Ceretta LB, Mendes C, Silveira PCL, Teixeira JPF, de Andrade VM. Mutagenesis. 2019 May 29;34(2):215. doi: 10.1093/mutage/gez006.Type 2 diabetes mellitus has undergone a worldwide growth in incidence in the world and has now acquired epidemic status. There is a strong link between type 2 diabetes and vitamin D deficiency. Because vitamin D has beneficial effects on glucose homeostasis, the aim of this study was to evaluate the influence of vitamin D3 supplementation on the modulation of glycaemic control and other metabolic effects, as well as modulation of genomic instability in patients with type 2 diabetes. We evaluated 75 patients with type 2 diabetes, registered in the Integrated Clinics of the University of Southern Santa Catarina. Participants received 4000 IU of vitamin D3 (25(OH)D) supplementation daily for 8 weeks. Blood samples were collected at the beginning and at the end of the supplementation, and 4 weeks after the end of supplementation. The glycidic and lipid profiles [total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein and triglycerides], oxidative stress, DNA damage and 25(OH)D levels were evaluated. Vitamin D3 supplementation for 8 weeks showed enough to significantly increase blood levels of 25(OH)D. A significant difference in lipid profile was observed only in non-HDL cholesterol. Significant changes were observed in glucose homeostasis (fasting glucose and serum insulin) and, in addition, a reduction in the parameters of oxidative stress and DNA damage. There was a significant reduction in the values of 25(OH)D 4 weeks after the end of the supplementation, but levels still remained above baseline. Use of vitamin D supplementation can be an ally in the health modulation of patients with type 2 diabetes mellitusThis work was supported by grants from Conselho Nacional de Pesquisa e Desenvolvimento (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Fundação de Amparo à Pesquisa e Inovação do Estado de Santa Catarina (FAPESC) and Programa de Pós-Graduação em Ciências da Saúde/ Universidade do Extremo Sul Catarinense.info:eu-repo/semantics/publishedVersio
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