Advances in proximal sensing: application of pedometrics in tropical soils

• Ano de defesa: 2023
• Autor(a) principal: Silva, Fernanda Magno
• Orientador(a): Silva, Sérgio Henrique Godinho
• Banca de defesa: Menezes, Michele Duarte de, Gomes, Felipe Haenel, Tavares, Tiago Rodrigues, Poggere, Giovana Clarice
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Lavras
• Programa de Pós-Graduação: Programa de Pós-graduação em Ciência do Solo
• Departamento: Departamento de Ciência do Solo
• País: brasil
• Palavras-chave em Português: Soil genesis; Spatial variation; Prediction models; PXRF; Vis-NIR; X-ray diffraction; Magnetic susceptibility; Portable X-ray fluorescence (pXRF); Visible near-infrared spectroscopy (Vis-NIR); VIS-NIR spectroscopy; Gênese do solo; Variação espacial; Modelos de predição; Difração de raios; Susceptibilidade magnética
• Área do conhecimento CNPq: Ciência do Solo
• Link de acesso: https://repositorio.ufla.br/handle/1/58458

Understanding pedogenesis, soil variability, its physical, chemical and mineralogical characterization and its respective parent materials is not always a simple and straightforward task, especially in tropical regions. Technological advances, methodologies and tools, such as portable X-ray fluorescence (pXRF) and diffuse reflectance spectroscopy in the visible and near infrared region (Vis-NIR) associated with X-ray diffraction (XRD) and magnetic susceptibility (MS) were employed to characterize soils, investigating their genesis and reducing costs. This study aims to use proximal sensors pXRF, Vis-NIR and MS associated with and XRD to: 1) characterize soils developed from different parent materials; 2) identify and quantify the mineralogy of sand, silt and clay fractions of different soils derived from different parent materials; and 3) assess the spatial variation of properties within soil profiles. Twenty-seven soil profiles were described in the region of Lavras and Ijaci (MG), with the collection of samples in 85 horizons for analysis. Samples from A, B and C horizons and the sand, silt and clay fractions of the respective horizons were analyzed by pXRF, Vis-NIR and MS. The analysis for mineralogy identification via XRD was performed on the sand, silt and clay fractions. The pXRF and MS revealed the diversity and alterations in the elemental composition of the soil profiles, showing how each parent material imprinted its characteristics on each of them. While Vis-NIR confirmed the mineralogy found through XRD and accurately predicted the contents of minerals present in the clay fraction. Proximal sensors allowed the detection of soil properties variation within and in between soil horizons. The relationship between the data obtained by the sensors allowed a more comprehensive, accurate and rapid assessment of soils and their properties, providing a complete analysis of the pedogenetic processes and the influence of the parent material on the characteristics of the soils studied.