Source-driven remobilizations of nutrients within stem wood in Eucalyptus grandis plantations

Nutrient remobilizations in tree ligneous components have been little studied in tropical forests. A complete randomized block design was installed in Brazilian eucalypt plantations to quantify the remobilizations of phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na) within stem wood. Three treatments were studied: control with neither K nor Na addition (C), 3 kmol ha-1 K applied (+K), and 3 kmol ha-1 Na applied (+Na). Biomass and nutrient contents were measured in the stem wood of eight trees destructively sampled at 1, 2, 3 and 4 years after planting in each treatment and annual rings were localized on discs of wood sampled every 3 m in half of the trees. Chemical analyses and wood density measurements were performed individually for each ring per level and per tree sampled. Nutrient remobilizations in annual rings were calculated through mass balance between two successive ages. Our results show that nutrient remobilizations within stem wood were mainly source-driven. Potassium and Na additions largely increased their concentration in the outer rings as well as the amounts remobilized in the first 2 years after the wood formation. The amount of Na remobilized in annual rings was 15 % higher in +Na than in +K the fourth year after planting despite a 34 % higher production of stem wood in +K leading to a much higher nutrient sink. A partial substitution of K by Na in the remobilizations within stem wood might contribute to enhancing Eucalyptus grandis growth in K-depleted soils. © 2013 Springer-Verlag Berlin Heidelberg.

Solid-phase extraction of metal ions from fuel ethanol with a nanostructured adsorbent

This work describes the synthesis and characterization of a new octakis[3-(2,2'-dipyridylamine)propyl]octasilsesquioxane (T8-Pr-DPA), and a study of the metal ion preconcentration in fuel ethanol. Batch and column experiments were conducted to investigate for the removal of heavy metal ions from fuel ethanol. The results showed that the Langmuir allowed to describe the sorption equilibrium data of the metal ions on T8-Pr-DPA in a satisfactory way. The following maximum adsorption capacities (in mmolg-1) were determined: 3.62 for Fe (III), 3.32 for Cr (III), 2.15 for Cu (II), 1.80 for Co (II), 1.62 for Pb (II), 1.32 for Ni (II) and 0.88 for Zn (II). The thermodynamic parameters for the adsorption process such as free energy of adsorption (δG), enthalpy of adsorption (δH) and entropy of adsorption (δS) were calculated. Thermodynamic parameters showed that the system has favorable enthalpic, Gibbs free energy, and entropic values. The sorption-desorption of the metal ions has made possible the development of a preconcentration and determination method of metal ions at trace level in fuel ethanol. The method of quantitative analysis for Fe, Cu, Ni and Zn in fuel ethanol by Flame AAS was validated. Several parameters have been taken into account and evaluated for the validation of method, namely: linearity, limit of detection, limit of quantification, and the relative standard deviation and accuracy. The accuracy of the method was assessed by testing analyte recovery in the fuel ethanol samples. © 2013 Elsevier B.V.

Cycling of nutrients and silicon in pigeonpea and pearl millet monoculture and intercropping

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Measurement of the hadronic activity in events with a Z and two jets and extraction of the cross section for the electroweak production of a Z with two jets in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of solvent effect on the extraction of phenolic compounds and antioxidant capacities from the berries: application of principal component analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Constraints on parton distribution functions and extraction of the strong coupling constant from the inclusive jet cross section in pp collisions at root s=7TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Extraction of natural red colorants from the fermented broth of Penicillium purpurogenum using aqueous two-phase polymer systems

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Alternative distributions to estimate usual intake of nutrients for groups

When assessing food intake patterns in groups of individuals, a major problem is finding usual intake distribution. This study aimed at searching for a probability distribution to estimate the usual intake of nutrients using data from a cross-sectional investigation on nutrition students from a public university in São Paulo state, Brazil. Data on 119 women aged 19 to 30 years old were used. All women answered a questionnaire about their lifestyle, diet and demographics. Food intake was evaluated from a non-consecutive three-day 24-hour food record. Different probability distributions were tested for vitamins C and E, panthotenic acid, folate, zinc, copper and calcium where data normalization was not possible. Empirical comparisons were performed, and inadequacy prevalence was calculated by comparing with the NRC method. It was concluded that if a more realistic distribution for usual intake is found, results can be more accurate as compared to those achieved by other methods.

Availability of nutrients, productive properties, and quality of sunflower ( L.) seeds in acid soils amended with different molar ratios between Ca and Mg

Liming is indispensable in acid soils for amending acidity; however, the technique may alter the cation balance in soil and, consequently, may limit the availability and uptake of nutrients. We aimed to evaluate different molar ratios between calcium (Ca) and magnesium (Mg) on the availability of soil nutrients and their influence on the productive properties of sunflower and seed quality. The experiment was carried out in a greenhouse under two types of contrasting soils and six molar combinations of CaCO3and MgCO3 in amendment of soil acidity to raise base saturation to 70%. After incubation, soil analysis was undertaken to verify the ratios obtained and nutrient availability. Morphological and production variables were analyzed at the end of the experiment, as well as accumulation of nutrients in the achenes and their physiological quality. In spite of equal base saturation between the types of soil, there were differences in the available contents of these cations. The increase in the Ca contents limited the Mg contents to the critical level of the sunflower. This result had a negative influence on the production properties of sunflower and physiological quality. In contrast, there was a compensation of the crop with greater accumulation of nutrients in the achenes under lower yield.

Macronutrient accumulation and partioning in fertigated sweet pepper plants

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Épocas de semeadura e manejos de corte de milheto cultivado no outono-inverno e efeitos na cultura da soja em sucessão sob plantio direto

Pós-graduação em Agronomia (Agricultura) - FCA

Curva de crescimento e exportação de nutrientes e sódio por frutos de mangueira Palmer, Haden e Tommy Atkins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Doses de potássio em cobertura na produção e qualidade de frutos de abobrinha-de-moita

Pós-graduação em Agronomia (Horticultura) - FCA

Avaliação de cultivares de alface crespa produzidas em hidroponia tipo NFT em dois ambientes protegidos em Ribeirão Preto (SP)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Composto orgânico de agroindústrias na produção de feijão de inverno e milho no sistema plantio direto

Pós-graduação em Agronomia - FEIS