Soil use and management systems, time since adoption, and their impacts over aggregation

The Cerrado biome is of notable territorial relevance in the state of Piaui, Brazil. This region is an area of reference for food production. The aim of this work was to evaluate the stability of soil aggregates in water, in function of different soil use and management systems, as well as of the time since adopting these systems in Cerrado areas in the southwest region of Piaui. In this study, nine soil use and management systems were evaluated, arranged in the following manner: no-tillage system of three and six years of use, pasture of two and six years, eucalypt of six and twelve years, conventional tillage of two and eight years, and native Cerrado (Savana). The analyzed variables were: organic carbon, mean geometric diameter, mean weight diameter, aggregate stability index and aggregate diameter classes. Aggregation in Ferralsol is favored by clay and organic carbon contents. The longer adoption time in the no-till, pasture and eucalypt systems favored soil aggregation, while in conventional tillage there was a reduction of the aggregates.