Banca de DEFESA: CARLOS ROBERTO PINHEIRO JUNIOR
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : CARLOS ROBERTO PINHEIRO JUNIOR
DATA : 03/09/2018
HORA: 09:00
LOCAL: Instituto de Agronomia - Departamento de Solos
TÍTULO:
Genesis and Characterization of the Soil of Carbonate Nature of the Italva Group
PALAVRAS-CHAVES:
Pedogenesis. Dolomite. Amorphous calcium carbonate
PÁGINAS: 89
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Ciência do Solo
ESPECIALIDADE: Gênese, Morfologia e Classificação dos Solos
RESUMO:
The carbonaceous rocks occur in approximately 10% of the terrestrial surface, occupying great part of the agricultural areas. Despite this wide scope, there are few pedological studies in these areas. The northwest region of Rio de Janeiro is part of the Italva Group, characterized by the occurrence of calcissilictic rocks and marbles, a material that is associated with drier climates and is responsible for the observation of soil attributes characteristic of these areas, such as high levels of calcium and magnesium, presence of carbonates, high activity clays. In this sense, the objective of the work was to characterize the morphological, physical, chemical, mineralogical attributes of the soils of a carbonate nature of the Italva Group and to interpret the performance of the main factors and processes in the pedogenesis. For the study, a toposequence was selected in the municipality of Italva, RJ, where 6 profiles were described and collected. The material of origin, climate and relief were the main factors responsible for the soil genesis influencing in several attributes such as high values of saturation by bases with predominance of Ca and Mg, high pH, presence of carbonates, high Ki ratio, low Fe2O3 contents , in addition to controlling the water flow, drainage condition and cations accumulation. The absence of effervescence and the high MgO/CaO ratio suggest the dolomitic nature of the carbonates. Despite the high carbonate content, these groups were not detected in the mineralogical analysis, based on the literature it is suggested the presence of amorphous calcium carbonate and protodolomite, both of which were not detected by X-ray diffraction. The main minerals found in the sand fraction were quartz, feldspar, mica and pyroxene, in addition to sepiolite possibly precipitated on protodolomite grains, while in the fraction there was presence of illite and kaolinite. The main active pedogenetic processes are melanization, calcification, eluviation/illuviation, argilopedoturbation and gleation. The profiles were classified as Chernossolo Rêndizo Lítico típico (summit); Chernossolo Háplico Carbonático saprolítico (shoulder); Argissolo Vermelho-Amarelo Eutrófico chernossólico (backslope); Typical Carbonic Echanic Chernosol (toeslope in colluvium ramp); Typical Carboniferous Flubic Cambisol (toeslope in alluvial dike) and; Typical Carbonic Hydromorphic Vertisol. The presence of compression surfaces associated to the formation of gilgai microrelevo should be added to the classification criteria of the Vertisols, considering that they indicate the occurrence of intense argilopedoturbation.
MEMBROS DA BANCA:
Interno - 1060711 - MARCOS GERVASIO PEREIRA
Externo ao Programa - 024.908.059-16 - ADEMIR FONTANA - EMBRAPA
Externo à Instituição - ANTONIO CARLOS DE AZEVEDO - USP