Simulação geoestatística na avaliação da qualidade física e estrutural de solos subtropicais

Abstract

There are several indicators of soil physical quality (SPQ) advocated in the literature, such as macroporosity, bulk density, saturated hydraulic conductivity, and the S-index. The S-index derives from the term "Soil structure" and is a parameter obtained from the soil water retention curve, being sensitive to different land uses and soil management practices. It primarily identifies structural changes related to the soil's original state. Using geostatistical simulation, the objectives of this study were to: i) define restrictive values for the S-index; ii) assess the impact of spatial uncertainties on the mapping of soil physical-hydraulic attributes; iii) identify restrictive zones of physical quality based on physical-hydraulic attributes, considering spatial uncertainties; iv) map potential restrictive zones of physical-hydraulic attributes; and v) develop physical vulnerability maps from restrictive scenarios of soil physical-hydraulic attributes. The geostatistical simulation proved efficient in the spatial characterization of soil attributes, with the study scale significantly influencing the final result. The proposed methodology identified that the limiting value of S-index = 0.02 does not suit the conditions of the BHSR. The geostatistical simulation identified limiting values for bulk density and the S-index for BHSR soils. The soil physical vulnerability indices, developed through sequential Gaussian simulation, identified zones of soil physical vulnerability and areas most prone to intervention in management practices, proving to be a viable tool to support decision-making regarding the management and conservation of SPQ.