The compaction caused by anthropic activities alters the soil physical properties, decreasing productivity and affecting the environment. Many studies on this topic have been conducted in agricultural soils; however there is little information in areas with native vegetation, where, usually, organic matter levels are higher. Thus, it is essential to evaluate the relationship between physical properties related to compaction under these conditions to establish reference values for the revegetation of native grassland or riparian forests. The objective was to relate maximum bulk density (MaxBD), optimum water content for compaction (OWC) and relative density (DR) with the limits of consistency, particle size and organic carbon content of predominant soils on the Southern Plateau of the State of Santa Catarina, Brazil, under native vegetation of temperate climate. Samples of A-Horizon were collected from two Oxisols (Rhodic and Xanthic Kandiudox), two Entisols (Lithic Udorthents and Typic Udipsamments) and two Inceptisols (Pachic Humudepts). The particle size distribution, particle density, total organic carbon content, limits of liquid, plasticity (LP) and stickiness, plasticity index, maximum bulk density (MaxBD), optimum water content (OWC) for compaction, bulk density, and the degree of compactness were evaluated. The MaxBD increases in soils with higher sand and fine sand content, and decreases in soils with higher clay content and higher liquidity and stickiness limits. The OWC decreases in sandy soils, especially those with a predominance of fine sand, and increases in those with higher clay content, total organic carbon and Atterberg limits. The OWC was between 0.76 and 1.05 times the plastic limit, directly related with the silt content, indicating that the optimum moisture content for compaction cannot be measured only by the determination of the plastic limit of a soil. The OWC/LP ratio of soils at higher altitude in the Southern Plateau of Santa Catarina is different from that of soils in other places, as a consequence of the high levels of organic matter and silt in these soils.
Standard Proctor test; relative bulk density; consistency limits
