The objective of this study was to evaluate the chiseling effect duration in an Oxisol, based on the study of soil and planter shank relation. The treatments were: no-till for 13 years; four years since chiseling (2001); two years since chiseling (2002); and six months since chiseling (2005), where all treatments were submitted or not to traffic with agricultural machinery. Data about vertical force and moment associated to: shank, soil mobilized area, specific operational resistance, macroporosity, microporosity, total porosity and soil density, were collected, and draught on shank was calculated. Increasing of time since chiseling required increasing of the forces, and six months since chiseling showed the smallest demand. Four years since chiseling had similar behavior to the no-till treatment, resulting in the smallest soil mobilized area and the greatest operational resistance. Physical property differences occurred only in layer 0-0.10 m, and recent chiseling showed the greatest soil macroporosity, and the smallest soil microporosity and bulk density. After four years, chiseling effect was not found on soil-planter shank relations.
soil compaction; specific operational resistance; no-tillage; clay soils
