Relações solo-paisagem em topossequência de origem basáltica
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Data
2012-06-01
Autores
Meireles, Humberto Teixeira [UNESP]
Marques Júnior, José [UNESP]
Campos, Milton César Costa
Pereira, Gener Tadeu [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Escola de Agronomia e Engenharia de Alimentos/UFG
Resumo
Variações nos atributos do solo dependem da posição do solo na paisagem e processos de drenagem, erosão e deposição. Este estudo objetivou avaliar os atributos físicos e químicos do solo, em uma topossequência de origem basáltica, na região de Batatais (SP). A área possui relevo aplanado e altitude oscilando entre 740 m e 610 m, em região dominada por basaltos. Foi estabelecido caminhamento de 3.000 m, a partir do espigão da vertente, no seu declive mais suave. As superfícies geomórficas foram identificadas e delimitadas conforme critérios topográficos e estratigráficos, com base em intensas investigações detalhadas de campo. Foram coletadas amostras laterais aos perfis modais representativos das diversas superfícies geomórficas (S.G.) da topossequência (S.G. I = topo; S.G. II = meia encosta e sopé de transporte; S.G. III = ombro e sopé de deposição), totalizando 142 amostras. Além disto, foram abertas trincheiras, nos segmentos de vertente inseridos nas superfícies geomórficas mapeadas. As amostras coletadas foram analisadas quanto à densidade do solo, textura, bases trocáveis (Ca2+, K+ e Mg2+), soma de bases, capacidade de troca catiônica, saturação por bases, pH (água e KCl), SiO2, Al2O3, Fe2O3 (ataque por H2SO4), óxidos de Fe livres extraídos com ditionito-citrato-bicarbonato e Fe mal cristalizado extraído com oxalato de amônio. Os resultados revelaram que os solos oriundos de basalto apresentaram atributos físicos e químicos com comportamento dependente das formas do relevo. Com o uso de técnicas estatísticas multivariadas, foi possível distinguir três diferentes ambientes, que equivalem às três superfícies geomórficas.
Variations in soil attributes depend on the soil position in the landscape and drainage, erosion, and deposition processes. This study aimed to evaluate the soil physical and chemical properties, in a toposequence developed from basaltic parent material, in Batatais, São Paulo State, Brazil. The area presents a flatter topography and altitude ranging from 740 m to 610 m, in a basalt-dominated region. The experiment was carried out along a transect of 3,000 m from the top downwards. The geomorphic surfaces were identified and delimited according to topographic and stratigraphic criteria, based on detailed field investigations. Samples were collected along the representative side of profiles, for each geomorphic surface (GS) of the toposequence (GS I = top; GS II = hillside and transport foothill; GS III = shoulder and deposition foothill), totaling 142 samples. In addition, trenches were opened in the slope segments of the mapped geomorphic surfaces. The samples were analyzed for bulk density, texture, exchange bases (Ca2+, K+, and Mg2+), sum of bases, cation exchange capacity, base saturation, pH (water and KCl), SiO2, Al2O3, Fe2O3 (H2SO4 attack), free Fe oxides extracted with dithionite-citrate-bicarbonate, and poorly crystallized Fe extracted with ammonium oxalate. The results showed that soils developed from basaltic parent material presented physical and chemical attributes tied to the relief shapes. The use of multivariate statistical techniques made possible to identify three different environments, which are equivalent to the three geomorphic surfaces.
Variations in soil attributes depend on the soil position in the landscape and drainage, erosion, and deposition processes. This study aimed to evaluate the soil physical and chemical properties, in a toposequence developed from basaltic parent material, in Batatais, São Paulo State, Brazil. The area presents a flatter topography and altitude ranging from 740 m to 610 m, in a basalt-dominated region. The experiment was carried out along a transect of 3,000 m from the top downwards. The geomorphic surfaces were identified and delimited according to topographic and stratigraphic criteria, based on detailed field investigations. Samples were collected along the representative side of profiles, for each geomorphic surface (GS) of the toposequence (GS I = top; GS II = hillside and transport foothill; GS III = shoulder and deposition foothill), totaling 142 samples. In addition, trenches were opened in the slope segments of the mapped geomorphic surfaces. The samples were analyzed for bulk density, texture, exchange bases (Ca2+, K+, and Mg2+), sum of bases, cation exchange capacity, base saturation, pH (water and KCl), SiO2, Al2O3, Fe2O3 (H2SO4 attack), free Fe oxides extracted with dithionite-citrate-bicarbonate, and poorly crystallized Fe extracted with ammonium oxalate. The results showed that soils developed from basaltic parent material presented physical and chemical attributes tied to the relief shapes. The use of multivariate statistical techniques made possible to identify three different environments, which are equivalent to the three geomorphic surfaces.
Descrição
Palavras-chave
Geomorphic surfaces, Multivariate analysis, Soil attributes, Superfície geomórfica, Análise multivariada, Atributos do solo
Como citar
Pesquisa Agropecuária Tropical. Escola de Agronomia e Engenharia de Alimentos/UFG, v. 42, n. 2, p. 129-136, 2012.