Road Tires Use inAgricultural Areas is Possible by Maintaining Soil Biomass

Brazil has a robust agricultural sector; however, the mechanization of crops causes several problems in the physical soil structure, including surface compaction. Compaction reduces crop productivity and producer profits. The intensity of compaction varies depending on the wheelset model used, tire type, water content, and soil load applied. Recent studies have shown that soil compaction in sugarcane can be attenuated by maintaining the vegetation cover (straw biomass) on the surface after harvesting. The present study used different tire models to evaluate the interaction between wheelset-soil as a function of different amounts of biomass left over from the sugarcane harvest. A physical simulation system (fixed tire testing unit) was used for the tests. The wheelsets were subjected to controlled loads on tanks with confined and standardized soil samples. The treatments consisted of 3 tire models (p1: road radial, composed of double wheelset - 2×275/80R22.5; p2: agricultural radial - 600/50R22.5; and p3: agricultural diagonal - 600/50-22.5) and three contact surfaces (s1: without vegetation cover; s2: soil with straw cover equivalent to 15mg ha^-1; and s3: soil with 30Mg ha^-1 vegetation cover), considering three replications. We performed principal component analysis (PCA) and regression analysis to results. We verified tire-soil contact area (CA) increased with the increase straw coverage and was inversely proportional to soil resistance penetration (PC). The highest resistance to soil penetration was obtained with the p1 tire on uncovered soil (s1). Road tires cause intense impact when no vegetation covers. We verified that intensity impact caused by the wheelsets in the crop would be determined by cover straw and tire model. For better results to soil preservation, it must maintain a minimum of 15Mg ha^-1 of coverage biomass.