Propriedades físicas do solo após tráfego da viatura blindada de transporte militar M113 BR no campo de instrução de Santa Maria, RS

Abstract

The physical properties of the soil can be changed after vehicle traffic, especially in high humidity conditions. The persistence and intensity of soil changes promoted by vehicle traffic are mainly dependent on factors such as texture, moisture, organic matter content and its stress history. The Santa Maria Instruction Field (CISM), where the experiment was carried out, is currently the instruction field for armored vehicles in Brazil with the highest use intensity, with the M113 BR being the most used armored vehicle. The objective of this work was to verify the effects of different traffic configurations of the M113 BR on the physical mechanical properties of an Abruptic Alisol. The study was conducted in a completely randomized design, independently evaluating the effect of straight and pivoting traffic in three soil layers (0.00-0.04, 0.10-0.14 and 0.20-0.24 m). For the straight-line traffic, were evaluated traffic intensities (TI) with one (TI1), two (TI2) and five (TI5) passes on the same trail. For the pivoting traffic, were evaluated TI with one (TI1P) and two (TI2P) pivots. Both studies had two non-traffic treatments (NT). It were made the analysis of the soil bulk density (Bd), total porosity (TP), macroporosity (Ma), microporosity (Mi), saturated soil hydraulic conductivity (Ks), soil penetration resistance (PR), soil bearing capacity, preconsolidation pressure, gravimetric water content, particle size distribution, total organic carbon, morphological description, general botanical composition and dry mass of the vegetation. In the straight-line traffic, prevailed the cases with no significant differences in TP, Ma, Mi and Ks. The highest TP, smallest Bd and largest Mi were observed in the 0.10-0.14 m layer. In the pivoting traffic, one pass was sufficient to increase Bd and decrease TP, Ma, Mi and Ks in the 0.00-0.04 m layer and the increase from one to two pivotings had significant difference only in Mi in this same layer. Both types of traffic intensity did not affect the PR in any layer. The Abruptic Alisol supports the loads resulting from M113 BR vehicle traffic when it occurs in a straight line. The pivoting maneuver promoted additional compaction to the topsoil, increasing its degradation. The preconsolidation pressure was not an adequate parameter to verify the soil's ability to support the loads applied by pivoting traffic