Evaluation of the Structure of Dry Soil, Subjected to Dynamic Load in Different Managements

The structural evaluation of agricultural soil is essential for the performance and quality of production. Soils suffer surface consolidation when subjected to agricultural machinery traffic and alter their physical characteristics according to the management to which it is subjected. Therefore, this work aimed to evaluate the physical indices and surface consolidation of a red oxisol subjected to different loads and types of management. Undeformed soil samples were collected from three areas with different management systems- no-tillage, crop-livestock--forest integrated system (CLFI), and pasture area. Traffic simulations were conducted with application of dynamic loads, using 0 pass, 1 pass, and 2 passes (0, 108, and 216 kpa), evaluating the physical indices of the soil's natural specific weight (yn), dry apparent specific weight (yd), void index (n), and porosity (e). Subsequently, the samples were subjected to uniaxial compression tests using loads (108, 216, 432, 864, and 1500 Kpa) to verify the surface consolidation. The experiment was conducted in a completely randomized design, with a 3x3x5 factorial scheme in sub-subdivided plots. Thus, we verified that the no-tillage management system has a more porous soil due to its characteristics, presenting lower resistance and being better for planting. CLFI was characterized as a management that allowed the soil to be more resistant to the application of loads and, therefore, less porous. Pasture has an intermediate behavior.