Atributos químicos e mineralógicos de uma cronossequência em sistema de plantio direto de latossolos vermelhos férricos

• Ano de defesa: 2013
• Autor(a) principal: Machado, Alini Taichi da Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Departamento de Agronomia; Programa de Pós-Graduação em Agronomia; UEM; Maringá, PR; Centro de Ciências Agrárias
• Palavras-chave em Português: Latossolos vermelhos; Plantio direto; Minerais de argila; Óxidos de ferro; Solos; Atributos químicos; Atributos mineralógicos; Solos tropicais; Brasil.; Clay minerals; Pedoenvironment; Iron oxides.Chemical attributes; Mineralogical attributes; Tropical soils; Brazil.; Ciências Agrárias; Agronomia
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/1183

The new chemical environment created after changing from a natural (Natural florest) to an agricultural system, among them the no-tillage, changes the chemical, physical and biological attributes, especially in the soil surface. All these new conditions may lead to changes in the minerals present in soils. There is little information in the literature on changes in surface mineralogical attributes of tropical soils, along the time of no-tillage. The objective of this work was to evaluate the chemical and mineralogical characteristics and changes in the clay mineralogy of a ferric Red Oxisols in a chronosequence of no-tillage system (NT). Soil samples from three profiles derived from basalt of 5, 10 and 20 years of implementation of no-tillage were collected at nine different depths to evaluate the attributes. The same sampling was taken in a closed area under natural forest, to compare the analyzed attributes. The changes in the chemical and mineralogical attributes of the soil clay fraction along the time of no-tillage were investigated using chemical and thermal analysis and X-ray diffraction. The values of active and potential acidity decreased along the time of no-tillage. The bases and organic carbon content were not correlated with the time of implementation of the management system. The free iron oxides (Fed) content and the free iron oxides / total iron oxides (Fet) ratio decreased with no-tillage development stage, while poorly crystalline Fe and Al oxides showed an opposite trend. There was no qualitative difference between time of implementation of the management system and mineralogy. Quantitatively, in the fine clay fraction, the 2:1 clay minerals content increased, while gibbsite content decreased with time of implementation of the no-tillage system. This same fraction had higher amounts of hematite compared to the total clay. Goethite was detected only in the fine clay fraction.