Spatial variability of iron oxides and phosphate adsorbed in soil Western Paulista Plateau

• Grant number: 17/01704-2
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): February 01, 2018
• Effective date (End): June 30, 2020
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: José Marques Júnior
• Grantee: Laércio Santos Silva
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated scholarship(s): 18/15694-1 - Spatial variability of iron oxides and emission of nitrogen gases (NOx) in soils of the São Paulo Western plateau, BE.EP.DR

Abstract

The Western Paulista Plateau is one of the main areas of citrus cultivation in the country, accounting for about 80% of the national production, with a significant participation in the production of sugar and alcohol. The geological and geomorphological diversity of this region is responsible for the spatial variability of iron oxides, mainly goethite, hematite and maghemite, and the soil attributes that would coexist with these oxides, such as adsorbed phosphorus. By recognizing the spatial variability of these oxides, it is possible to identify areas with different phosphorus adsorption potentials, allowing the application of more accurate doses of fertilizers, minimizing risks of loss and optimizing costs. Thus, the agricultural advance in these areas requires investments in technologies, such as the use of tools such as geostatistics and geomorphometry in the identification of the variability of iron oxides. In this sense, the objective of the present project is to study the spatial variability of the iron oxides of the clay fraction and covariate attribute - phosphorus adsorbed, in the soils of the Western Paulista Plateau, using diffuse reflectance spectroscopy. The study area is the Paulista Western Plateau, which corresponds to approximately 13 million hectares (~ 50% of the State of São Paulo), supported essentially by arenitic and basaltic rocks, with landscape at different stages of evolution, denominated in this study as little , Intermediate and highly dissected (geomorphology). A total of 300 samples were collected in the year 2015, at a depth of 0.0 - 0.2 m, along the highways of the state at sites representative of the geological and geomorphological compartments. The samples will be analyzed by X-ray diffraction and diffuse reflectance spectroscopy. Subsequently, the study of the spatial variability of the iron oxides and adsorbed phosphorus will be carried out, relating the mineralogical data to the geomorphometric map, through statistical and geostatistical analysis. With this, the results obtained by diffuse reflectance spectroscopy are expected to generate maps of the spatial distribution pattern of goethite and hematite taking into account the geomorphological compartments at different stages of evolution, in order to help identify areas with different potential of adsorption of phosphorus. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SILVA, LAERCIO SANTOS; MARQUES JUNIOR, JOSE; BARRON, VIDAL; GOMES, ROMARIO PIMENTA; TEIXEIRA, DANIEL DE BORTOLI; SIQUEIRA, DIEGO SILVA; VASCONCELOS, VINICIUS. Spatial variability of iron oxides in soils from Brazilian sandstone and basalt. CATENA, v. 185, FEB 2020. (18/15694-1, 17/01704-2)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SILVA, Laércio Santos. Quantification of lithopedogenic iron oxides by diffuse reflectance spectroscopy and magnetic susceptibility for mapping purposes. 2020. Doctoral Thesis - Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal Jaboticabal.