An experiment was carried out in order to evaluate the effects of soil compaction on the physical characteristics of two soils: a oxidic-gibbsitic Red Yellow Oxisol (LVA) and a caulinitic Yellow Oxisol (LA). The experiment consisted of eight levels of pressure applied to compact the soil (0, 60, 120, 240, 360, 540, 720 e 900 kPa). The experimental unit was composed of a PVC pipe with 6 cm in height and 4.55 cm of internal diameter to evaluate: hydraulic conductivity, microporosity, macroporosity, total porosity, soil penetration resistence and water-stable aggregates. Soil water retention at 0.01 and 1.5 MPa was evaluated using the samples compacted in the PVC pipe with 1.9 cm in height and 4.55 cm of internal diameter. The caulinitic soil was more sensitive to soil compaction than the to oxidic-gibbsitic soil. The increase of microporosity with soil compaction increased the soil water retention at 0.01 and 1.5 MPa, however it did not affect available water holding capacity. The properties of soil which have higher sensibility to effects of soil compaction were hydraulic conductivity and penetration resistence.
hydraulic conductivity; soil porosity; penetration resistence; soil water retention
