A former concern related to agricultural soil, under no tillage systems, might be the state of compaction due to farm machinary traffic. Two treatments corresponding to two different tillage systems (disk plowed, LC, and no tillage, SD) included four traffic subtreatmets (0; 80; 160, and 240 Mg km ha-1) on a Typic Hapludert. Cone index (IC) and dry bulk density (DA) were the experimental dependent variables asessed. Soil reology under traffic had a different behaviour in both treatments. In both treatments for the higher traffic intensities (160 and 240 Mg km ha-1) statistical significant difference (P < 0,05) were measured when compared with the control plots, when the IC was considered. Considering LC treatment and the higher traffic intensities, the dry bulk densities values measured arised to 1.83 Mg m-3, the disk plowed, and no tillage under traffic soils reologies are different. If the depth of the maximum response in terms of IC measurements is considered, a direct relationship between traffic intensities and depth, could be stablished.
soil compaction; agricultural traffic; no tillage system
