Crop succession mitigates cumulative soil compaction and preserves soil physical quality under silage maize production

Brazilian silage maize production relies on intensive machinery traffic, which may progressively impair soil physical quality under continuous monoculture. This study evaluated whether soybean succession mitigates cumulative soil compaction and preserves soil physical quality in tropical Oxisols managed under silage maize over two consecutive crop seasons. Despite the widespread adoption of silage maize in tropical regions, little is known about how crop succession modifies the temporal evolution of soil compaction and soil physical quality under repeated machinery traffic in these systems. A quasi-experimental time-series design was adopted. Soil samples were collected from the 0–5 and 20–25 cm layers on four sampling occasions. Initial samples were used to develop load-bearing capacity models (LBCM) and identify the initial soil properties, followed by three successive samplings before and after harvest in each crop cycle. Bulk density (Bd), pre-consolidation pressure (σp), total porosity (Tp), microporosity (Mic), macroporosity (Mac), and organic matter (OM) were determined. LBCMs were developed and fitted to a regression model of the type σp = 10(a + bθ). Other soil properties were analyzed using linear mixed models. Crop succession reduced the proportion of compacted samples throughout the study and improved key indicators of soil physical quality, including Bd and Mic. In contrast, continuous silage maize monoculture promoted progressive subsurface compaction, increased microporosity, and reduced Mac. The σp proved more sensitive than Bd for detecting management-induced changes in soil mechanical behavior. Overall, soybean succession mitigated the cumulative effects of repeated machinery traffic, preserving soil physical quality under continuous silage maize production. These findings highlight load-bearing capacity models as valuable tools for monitoring soil compaction and supporting sustainable soil management in tropical production systems.