EVALUATION OF SOIL PHYSICAL QUALITY INDEXES AND PREDICTION OF MULTIFRACTAL PARAMETERS OF SOILS UNDER SEMI-DECIDUOUS FOREST

Author(s)

Thalita Campos Oliveira

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2013-05-07

Examining board members

Miguel Cooper; Daniel Gimenez; Luiz Fernando Pires

• Advisor: Miguel Cooper

Abstract

The Atlantic Forest originally covered around 150 million hectares undergoes constant degradation. Nowadays, only 7-8% of the original forest still remains, mostly as secondgrowth forests. The Caetetus Ecological Station has one of the most significant areas of Semideciduous Forest which covered almost all the interior of São Paulo State, part of Minas Gerais, Mato Grosso do Sul, Paraguay and Argentina. To understand the relationship between original vegetation and soil detailed studies are necessary which includes the hydro-physical soil function allowing to characterize the soil behavior. Thus, physical properties have strong influence in the chemical and biological relations and play a central role in studies of soils processes dynamics. The objective of this research was to obtain quantitative parameters of soil structure by multifractal analysis using hydro-physical database and soil micromorphology images of soils under Semi-deciduous Forest in a permanent plot of Caetetus Ecological Station (Gália - SP, Brazil) and compare soil physics quality values with of soil physical quality values founded in the literature, providing data to evaluate soil quality in areas with different soil uses. Three soil quality indexes were used, S index, relative air capacity (ACt/Pt) and relative field capacity (FC/Pt). The soils horizons showed different shapes and symmetries by multifractal analysis indicating differences of pores distribution, the parameters of multifractal shape f(?)ratio, ?ratio and ?? (p < 0.05) showed significant differences. The S values founded were higher and lower than the limit of soil physical quality proposed (0,035). The A and E horizon showed the highest values because its sandy texture allow high n values. The B horizons showed the lowest values, because its natural densificaition decreases the n values. The values founded for ACt/Pt and CC/Pt were higher and lower than the ideal limits. The results founded suggest a reevaluation of the ideal soil physical quality limits for tropical regions. Trough the quantification and integration of soil space properties, the multifractal analysis can improve structure classification systems and create a structure parameter that can be added in pedotransfer functions. (AU)

• FAPESP's process: 11/05453-8 - Prediction of water-physical attributes from different levels of soil quality
• Grantee: Thalita Campos Oliveira
• Support Opportunities: Scholarships in Brazil - Master