Prediction of soil stresses and compaction due to agricultural machines in sugarcane cultivation systems with and without crop rotation

One strategy to eliminate or minimize occurrence of soil compaction in sugarcane production is through modelling, which can identify the risk associated with different operations and machine equipment. Soil damage resulting from the passage of machines can be than reduced through preventive measures which focus on the soil-machine relationship. In the present study, the magnitudes and distribution of the stresses produced in the soil through the loads carried by the axles of the machines used in sugarcane cultivation systems were analysed and modelled. The Tyres/Track and Soil Compaction (TASC) tool took the soil and machine data, estimated contact areas and mean contact pressures at the soil-tyre/track interface, and associated with preconsolidation stress data obtained in the uniaxial test modelled the propagation of the applied stress into the soil. The traffic light after conventional tillage promotes soil compaction, while on areas with less intensive soil tillage, as the soil has greater load bearing capadty, the stress dissipates in the surface layers. There was a severe risk of soil compaction for three operations before sugarcane harvesting: crop rotations planting, harvesting of the peanut rotational crop, and planting of the sugarcane billets, with subsoil compaction extending down to 0.33 m. On harvesting, trailer has the higher potential to cause soil compaction, with a compressive stress of 157 kPa, at 0.21 m depth, greater than the preconsolidation pressure of all cultivation systems tested. Crop rotation systems associated with soil tillage that promote intense soil disaggregation increase the risk of soil compaction, which is not compensated by other advantages of such systems, and the soil is easily compacted by the subsequent agricultural machine traffic. The results indicate strategies to avoid soil compaction by machines used in sugarcane cultivation systems, including adjustments on machine loads and changes in tillage and management design. (C) 2019 Elsevier B.V. All rights reserved. (AU)