Propriedades mecânicas de solo franco arenoso sob distintos sistemas de preparo, tráfego mecanizado e resíduos vegetais

Abstract

The excessive mobilization of the soil causes losses to its structure. This is eliminated with the no tillage system, where mobilization only occurs in the planting line. However, considering that lately there was an increase in the use of the agricultural soils and of the mechanization, compaction problem in the surface soil layer in the system of no tillage has increased. The study had the objective of determining the effect of the compaction state which was accomplished in a Hapludalf, where in the first study soil sample were collected at two depths for the accomplishment of the tests, and in the second study samples were collected in four depths. In the first study, we determined uniaxial compression, direct shearing trials, penetration resistance, water retention curves, and soil density with the objective of evaluating different soil tillage changes in the physical properties of the soil. The results showed that the soil tillage did not have a significant effect on the soil physical properties evaluated. The second study had as objective the evaluation of the effect of the corn straw in the reduction of soil compaction in the field and in laboratory to verify the supposition that the corn straw absorbs energy with the traffic of agricultural machines. The laboratory tests showed that straw has a significant effect in the reduction of the soil compaction, but that did not have an effect when the soil was submitted to the traffic of agricultural machines in the field.