Soil compaction caused by traffic is a limiting factor to obtain high agricultural production. A study was carried out on experimental area of Soil Science Department, Federal University of Santa Maria, state of Rio Grande do Sul, Brazil, in a Typic HAPLUDALF with objectives of evaluating the effects of different traffic levels on soil physical alterations in no-tillage system. A front buck loader of 10Mg weight with radial tires, 0.35MPa inflated, causing a tire/soil pressure of 0,11MPa were used to induce the compaction levels over all plot area. The treatments were: T0 - without additional compaction; T1 - compaction caused by double pass of 10Mg loader and; T3 - compaction caused by four passes of the 10Mg loader. The tractor traffic induced the reduction of total porosity and macroporosity, and the increase of microporosity, bulk density and soil resistance to penetration. The soil resistance to penetration was the measurement that better separated the traffic level effects on soil physical properties.
density; porosity; penetration; resistance
