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52 results

Tipping Bucket Prototype for Automatic Quantification of Surface Runoff Rate in Plots

André Somavilla, Paulo Ivonir Gubiani ORCID logo , Anderson Luiz Zwirtz

07/Jan/2019

ABSTRACT: Quantification of runoff rate is an onerous task with non-automated devices; it requires a lot of manual labor to perform measurements. In this study, an automatic device to quantify the surface runoff rate from plots with a small area was developed and tested. The prototype was based on the tipping bucket technique and built with reused materials. Its performance was tested in the laboratory and a calibration curve was developed to improve measurement accuracy. The device can be used […]

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Pedological Studies of Subaqueous Soils as a Contribution to the Protection of Seagrass Meadows in Brazil

Gabriel Nuto Nóbrega, Danilo Jefferson Romero, Xosé Luis Otero, Tiago Osório Ferreira

05/Feb/2018

ABSTRACT: Seagrass meadows are considered one of the most important and valuable ecosystems on the planet, but also one of the most threatened. Missing knowledge about their existence and their subtidal nature are the main reasons for the lack of information about seagrass soils, especially in Brazil and other tropical areas. This study discussed the paradoxical lack of information about subaqueous soils, with a view to stimulate research on soil properties of seagrass meadows. This short communication provides information about […]

Fertilization of ornamental plants: requirement-supply method

Alvarez V. Víctor Hugo, André Ferreira Santos, Gláucio Leboso Alemparte Abrantes dos Santos, Patrícia Morais da Matta

01/Apr/2014

The recommendation of a fertilizer dose for a crop depends on nutrient gain-loss balance in the agricultural system (Restitution Law). At the Federal University of Viçosa (UFV), this balance has been modeled for liming and fertilizer recommendations for eucalyptus (NUTRICALC), pineapple, cotton, rice, banana, coffee, sugarcane, coconut, orange, melon, maize, pastures, soybean, tomato (FERTICALC), and for teak (FERTI – UFV). Fertilization and nutrition of tropical ornamental plants is based on the knowledge of growers and fertilizer manufacturers. This study was […]

Numerical modeling of the effect of variation of boundary conditions on vadose zone hydraulic properties

Tairone Paiva Leão, Randall Gentry

01/Feb/2011

An accurate estimation of hydraulic fluxes in the vadose zone is essential for the prediction of water, nutrient and contaminant transport in natural systems. The objective of this study was to simulate the effect of variation of boundary conditions on the estimation of hydraulic properties (i.e. water content, effective unsaturated hydraulic conductivity and hydraulic flux) in a one-dimensional unsaturated flow model domain. Unsaturated one-dimensional vertical water flow was simulated in a pure phase clay loam profile and in clay loam […]

Evaluation of sample preparation methods and optimization of nickel determination in vegetable tissues

Rodrigo Fernando dos Santos Salazar, Marco Aurélio Kondracki de Alcântara, Hélcio José Izário Filho

01/Feb/2011

Nickel, although essential to plants, may be toxic to plants and animals. It is mainly assimilated by food ingestion. However, information about the average levels of elements (including Ni) in edible vegetables from different regions is still scarce in Brazil. The objectives of this study were to: (a) evaluate and optimize a method for preparation of vegetable tissue samples for Ni determination; (b) optimize the analytical procedures for determination by Flame Atomic Absorption Spectrometry (FAAS) and by Electrothermal Atomic Absorption […]

Soil suitability and genetic algorithms for spatial organization of agrarian reform projects

Jose Ambrósio Ferreira Neto, Mayron César de Oliveira Moreira, Edgard Carneiro dos Santos Junior, Urbano Fra Paleo, João Luiz Lani

01/Feb/2011

The definition of family settlement plots in land reform projects involves technical and social issues. These aspects are mainly related to differences in the agricultural suitability of the soil in these projects. The objective of this study was to introduce a procedure for an optimal subdivision of the land by cross-linking projects by a Genetic Algorithm (GA). The GA was tested in the rural settlement Veredas, located in Padre Paraíso, in the region of the Vale do Jequitinhonha, State of […]

Effect of NPK fertilization on production and leaf nutrient content of eucalyptus minicuttings in nutrient solution

José Pereira Carvalho Neto, Enilson de Barros Silva, Reynaldo Campos Santana, Paulo Henrique Grazziotti

01/Feb/2011

Adequate nutrient levels in plants vary according to the species or clone, age and management practice. Therefore, adjustments of the nutrient solution are often necessary according to the plant material for multiplication. This study aimed to evaluate the influence of NPK fertilization on production and leaf nutrient contents of eucalyptus cuttings in nutrient solution. The study was conducted from November 2008 to January 2009 in a greenhouse. The experimental design was completely randomized fractional factorial (4 x 4 x 4)1/2, […]

Multiparametric adjustment program of potentiometric titration curves of humic acids

Clausius Duque Gonçalves Reis, Rita A. Dutra Fonseca, Efraim Lázaro Reis, César Reis, Carla Regina Guimarães Brighenti, Alexsandro Antônio Matias

01/Apr/2010

Regarding the difficulty of determining the inflection points in the potentiometric titration curve of humic acids by means of traditional methodologies, a Delphi program a Delphi program was developed for the multiparametric data adjustment in potentiometric titration. For this purpose, an iterative process was used, based on the Newton-Raphson method to estimate the roots of a polynomial. The humic acid potentiometric titration data, used in regressions, were obtained in an automated system of potentiometric titration. The program developed in Delphi […]

Physical and chemical properties of a soil under different production systems and forest in the Zona da Mata region of minas gerais state (Brazil)

Arley Figueiredo Portugal, Oldair Del'Arco Vinhas Costa, Liovando Marciano da Costa

01/Apr/2010

Knowledge on chemical and physical soil properties provides the theoretical basis for a sustainable planning of natural resources. This study evaluated the alteration of chemical and physical soil characteristics in a Haplustox in the Zona da Mata region of the State of Minas Gerais (Brazil), under different crop systems. The systems evaluated were orange orchards, sugar-cane plantation, pasture and forest, as control. Orange orchards and pasture had been established more than 20 years before, both in succession to sugar-cane, previously […]

Phosphorus extracted with Mehlich-1 determined by colorimetric and ICP methods in South Brazilian soils

Leandro Bortolon, Clesio Gianello

01/Feb/2010

The adoption of ICP technique to determine P in soil testing has been questioned, due the values determined with this technique is not comparable that those determined with colorimetric method. In the USA, some laboratories are restricted to adopt the ICP technique due the follow reasons: the nutrient recommendations to plants were developed for colorimetric method for P determination; significantly differences have been obtained between P determined with colorimetric and ICP techniques, because the high plasma temperature can measure other […]

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