Physical properties of Oxisol under conventional corn cultivation and no-till management systems

Searches for soil management systems that aim at maintaining soil quality are fundamental, along with sustainable agricultural and farming management. Thus, the aim of the present research was to assess soil parameters such as porous system, soil resistance to penetration, aggregate stability, relative soil density and the S index of an Oxisol under the conventional and no-till sowing management systems of corn production. They soils of the experimental areas were classified as a typical Oxisol with medium texture (LVd1) and typical Oxisol of clayey texture (LVd2). The experimental design was completely randomized split plot, with six replications. The plots (60 m2) consisted of six soil management systems (1 - SD1LVd1 = after one year no-till sowing; 2 - SD8LVd1 = after 8 years no-till sowing; 3 - SD10LVd1 = after 10 years no-till sowing; 4 - CCLVd1 = conventional sowing; 5 - SD12LVd2 = after 12 years no-till sowing; 6 - CCLVd2 = conventional sowing) and the subplots consisted of three soil layers (0-0.10, 0.10-0.20 and 0.20-0.30 m deep). The results showed that in three analyzed layers, the no-till sowing on medium texture Oxisol had higher densities. Treatments of medium texture Oxisol showed higher values of maximum soil density. This occurred because the clay content influenced a larger quantity of surface charges and specific surface area which decreased the susceptibility to soil compacting. The 12-year-old no-till sowing yielded the lowest corn productivity (5.9 Mg ha-1), probably due to the formation of compact layers, mainly near the soil surface.