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Accueil du site → Master → Brésil → Assessment of soil salinity sensor using the electromagnetic induction and geoestatistica in alluvial vale in Agreste of Pernambuco / Avaliação da Salinidade do Solo Utilizando Sensor de Indução Eletromagnética e Geoestatística em Vale Aluvial no Agreste de Pernambuco

Universidade Federal Rural de Pernambuco (2008)

Assessment of soil salinity sensor using the electromagnetic induction and geoestatistica in alluvial vale in Agreste of Pernambuco / Avaliação da Salinidade do Solo Utilizando Sensor de Indução Eletromagnética e Geoestatística em Vale Aluvial no Agreste de Pernambuco

Costa Netto Manoel Leal da

Titre : Assessment of soil salinity sensor using the electromagnetic induction and geoestatistica in alluvial vale in Agreste of Pernambuco / Avaliação da Salinidade do Solo Utilizando Sensor de Indução Eletromagnética e Geoestatística em Vale Aluvial no Agreste de Pernambuco

Auteur : Manoel Leal da Costa Netto >

Université de soutenance : Universidade Federal Rural de Pernambuco

Grade : Mestre Engenharia Agricola 2008

Résumé
The water stored in alluvial areas emerges as a main alternative for the supply and development of the small-scale agriculture, also known as communal. However, the water quality is not always appropriate, which may cause soil salinization in irrigated areas. Among the methods for measuring soil salinity, it can be highlighted the electromagnetic. In this work, readings were performed using an EM38 electromagnetic induction unit for the determination of the apparent electrical conductivity (ECap), placing it in the vertical and horizontal position. Addition to positioning on tem soil surface, equipment was willing held at different heights above the surface, in order to enable a proper calibration for the estimation of the actual soil electrical conductivity (ECa). For this, hence soil samples were collected at different depths profile, aiming to provide an performance assessment of the methodology. The readings of the apparent conductivity allowed to verify the salinity estimates based on regressions available in the literature. Additionally, multiple linear regressions were developed for local conditions of the alluvial valley. The results were analyzed by descriptive classic statistics, and through geostatistics. The objective of this study was to characterize the spatial distribution of soil electrical conductivity in alluvial valley with family communalfarming in the semi-arid of Pernambuco state. Statistical analyses showed the ECa data can be adjusted to a normal distribution. Through geostatistics it was built experimental semivariograms, subsequently adjusted to a theoretical model. The ECa presented spatial dependence on a plot scale at depths of 0-0.30 and 0.30-0.60 m with best fit obtained for the gaussian model. It was found that the EM38 is a suitable tool in mapping soil salinity, when subjected to local calibrations, and in a plot scale (tens of meters), and a valley one (hundreds of meters), even in areas with relevant vertical heterogeneities

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Page publiée le 3 avril 2010, mise à jour le 8 août 2018