Cultivo mínimo: efeito da compactação e deformação abaixo da atuação da ponteira do subsolador

A B ST R A C T Soil compaction at the depth of mobilization by tillage implements may occur under some soil conditions. The objective of this study was to verify the existence of compaction under the working depth and evaluate the effect of chisel plow in soil under determined levels of compaction. The treatments in study were 13 years of no-tillage and no-tillage with additional compaction. Horizontal force (F H ), Draught (F T ), vertical forces (F V ), and moment (Mo) associated the chisel tool, operation specific resistance, mobilized area, elevation area, swelling, soil penetration resistance, and physical properties of soil were determined. The additional compaction showed an increment of 18.9% in the horizontal force and draught. The greatest contribution of additional compaction was in vertical force, which provided an increment of 78.2%, showing that the load action is mainly in the vertical direction. No-tillage demonstrated smaller draught demand per mobilized soil area compared to additional compaction treatment. Instead of occurring compaction under the chisel action depth, there was soil mobilization, resulting in smaller soil mechanical penetration resistance in this layer.