Physical attributes of yellow oxisol under different monocultures in the savanna of Piauí state, Brazil

Abstract

The objective of this study was to evaluate the physical attributes of an oxisol under soybean monoculture, eucalyptus monoculture, and pasture and native forest conditions at depths of 0–0.20 and 0.20–0.40 m. Disturbed and undisturbed soil samples were collected to perform physical analyses. Specific analyses included texture, soil density, macroporosity, microporosity, total porosity, aggregate stability index, weighted mean diameter, percentage of aggregates with a diameter of >2.00 mm, and soil penetration resistance (PR). The data were analyzed using the Tukey’s test for the comparison of mean values and multivariate analysis. Different uses and management of the soil affected its physical attributes, resulting in the deterioration of soil quality in the soybean and pasture areas. Soil management systems in pasture and soybean areas also resulted in higher soil density and lower soil porosity. The eucalyptus monoculture showed soil aggregation equal to that of the native forest. There was a sharp increase in soil PR beyond the 0.15-m deep layer in the pasture and soybean management systems. Multivariate analysis identified variables that correlated with each type of soil management and the effects of changes in soil characteristics.