Granulometry and Stability of Aggregates in Different Land Uses in the Santa Catarina Plateau of Southern, Brazil

The aim of the present work was to determine the granulometry and stability of aggregates in different types of land use in the Santa Catarina Plateau of southern, Brazil. The research was conducted on Capão Alto, Santa Catarina, Brazil. The land use types selected were natural forest (NF), stands pine (SP), crop-livestock integration (CLI), and burned natural rangeland (BR). The definition of the collection points in the field was performed by means of a random sample survey, with nine sampling points by type of use. The stability of aggregates in water, expressed by the mean geometric diameter of aggregates (MGD), was performed after separation of the larger aggregates in smaller aggregates by a set of sieves with 8 and 4.76 mm. Subsequently, these aggregates were fractionated by means of a set of sieves of 4.76; 2.00; 1.00; and 0.25 mm by means of shaking submerged in water. The levels of sand, silt and clay presented differences between the types of land use. MGD ranges from 4.43 to 5.70 mm in NF; from 4.06 to 5.81 mm in SP; from 3.00 to 5,45 mm in CLI; e 4.35 to 5.57 mm in BR. In general, the results showed that MGD varied little in the different types of use, and in all treatments there was a trend of decreasing soil MGD with increasing depth.