One of the limitations for sustainable forest development is related to wheel traffic during harvest operations and wood transport, which can cause soil structure degradation. Seeking a solution for this problem, this study aimed to: a) propose a sustainability model of the structure of the soils cultivated with Eucalyptus spp., in Peçanha-MG as a function of the preconsolidation pressure (sigmap) and moisture content (U) and b) determine, throught the use of this model, the effect of the harvest operations using Feller Büncher and Skidder (tire 30.5L.32), Feller Buncher and Skidder (tire 66.43.00.26) and Harvester and Forwarder on the soil structure. This study was conducted on a Red-Yellow Latosol under Eucalyptus, using undisturbed soil samples collected before and after harvest operations at 0.10-0.125 m depth. The undisturbed soil samples were used in the uniaxial compression tests. Particle size distribution and particle density were also determined. The soil sustainability model for the RedYellow Latosol structure obtained for the projects in this study is expressed by the equation sigmap = 10(2,72-1,29 U). The use of the soil structure sustainability models and the preconsolidation pressure determined after wheel traffic allowed to quantify the effects of Feller-Büncher and Skidder (tire 30.5L.32), Feller-Büncher and Skidder (tire 66.43.00.26) and Harvester and Forwarder on the Red-Yellow Latosol structure. In the Buriti and São Leonardo Projects, the operations with Harvester and Forwarder degraded the soil structure the most, while in the Dourado Project the operations with Feller-Büncher and Skidder (tire 30.5L.32) and Feller-Büncher and Skidder (tire 66.43.00.26) caused more soil structure degradation.
Soil compaction; preconsolidation pressure; Eucalyptus spp.; sustainability; mechanical operations
