Contents lists available at ScienceDirect Geoderma journal homepage: www.elsevier.com/locate/geoderma Impact of permanent traffic lanes on the soil physical and mechanical properties in mechanized sugarcane fields with the use of automatic steering Diego Alexander Aguilera Esteban a, ⁎ , Zigomar Menezes de Souza b , Reginaldo Barboza da Silva c , Elizeu de Souza Lima a , Lenon Henrique Lovera a , Ingrid Nehmi de Oliveira a a University of Campinas (UNICAMP) – School of Agricultural Engineering (FEAGRI), Av. Cândido Rondon, 508, Campinas, SP 13083-875, Brazil b Department of Water and Soils, University of Campinas (UNICAMP) – School of Agricultural Engineering (FEAGRI), Av. Cândido Rondon, 508, Campinas, SP 13083- 875, Brazil c São Paulo State University (UNESP), Experimental Campus of Registro, Street Nelson Brihi Badur, 430, Registro, SP 11900-000, Brazil ARTICLE INFO Handling Editor: Cristine L.S. Morgan Keywords: Controlled traffic Soil compaction Tensile strength Preconsolidation pressure Soil friability ABSTRACT The randomized traffic during all crop cycles in the Brazilian sugarcane production system enhances soil compaction. The use of automatic steering in controlled traffic farming represents an alternative to minimize soil compaction in the sugarcane fields. Our research aimed to evaluate the changes in the soil physical and me- chanical properties under permanent traffic lanes, after three years of sugarcane mechanized harvesting, with the use of automatic steering. The experiment was carried out in the municipality of Nova Europa, state of São Paulo, Brazil, in a sugarcane area, under the following treatments: sugarcane planted in a single-row spacing (1.5 m) with conventional traffic, sugarcane planted in a single-row spacing (1.5 m) with automatic steering, and sugarcane planted with double-combined row spacing (1.50 × 0.90 m) and with automatic steering). The bulk density, soil porosity, soil penetration resistance, aggregate stability, and tensile strength of aggregates, were assessed in the inter-row center and seedbed. Soil load-bearing capacity was also included in this study by modeling of preconsolidation pressure at 0–0.1 m and 0.2–0.3 m of depth. After three years of mechanized operations, with controlled traffic using automatic steering, in a sugarcane field, the soil compaction was higher on the inter-row center (i.e. higher bulk density, tensile strength, and preconsolidation pressure and, lower macroporosity) than on the seedbed. The load-bearing capacity allowed to detect the pronounced effect of the machines’ traffic management systems on the soil compaction. The use of automatic steering reduced the load- bearing capacity in the seedbed in relation to the inter-row center, indicating that such management system preserves the soil physical quality in the ratoon region. Moreover, the lowest soil compression index values observed in the inter-row center, using management systems with automatic steering, indicates a lower sus- ceptibility to undergo additional soil compaction. 1. Introduction Sugarcane cultivation involves a range of mechanized operations, from the soil tillage to the harvesting, scheduled once a year, which causes heavy traffic on the soil and compaction issues. The upscaling of the size and weight of the agricultural machinery employed in these activities aggravates the soil compaction issue and increases energy requirements, CO 2 emissions and the difficulties in soil tillage, while it reduces plant emergence and growth, and productivity (Bochtis et al., 2010). The machines used in the harvesting can cut one sugarcane row at a time, which implies the need for heavy traffic in a certain area to complete the process. Additionally, it may promote the accumulation of traffic near the planting row, or occasionally directly on the row (Braunack and McGarry, 2006). Hence, the degradation of the soil physical properties that results from soil compaction by continuous machine traffic, is a major negative https://doi.org/10.1016/j.geoderma.2019.114097 Received 1 July 2019; Received in revised form 21 October 2019; Accepted 15 November 2019 Abbreviations: σ p , preconsolidation pressure; BD, bulk density; DRAS, sugarcane planted with double-combined row spacing (1.5 x 0.9 m) and management with automatic steering; IRC, inter-row center; LBCS, load-bearing capacity of the soil; LL, liquid limit; Cc, compression index; MaP, macroporosity; MiP, microporosity; PL, plastic limit; PR, soil penetration resistance; R, planting row; S, seedbed; SL, shrinkage limit; SR, sugarcane planted with single-row spacing (1.5 m) and management with no automatic steering; SRAS, sugarcane planted with single-row spacing (1.5 m) and management with automatic steering; TP, total porosity; U, soil water content ⁎ Corresponding author. E-mail address: aguilerae.soilres@outlook.com (D.A.A. Esteban). Geoderma 362 (2020) 114097 0016-7061/ © 2019 Elsevier B.V. All rights reserved. T