Compactação do solo e estratégias de manejo no sistema de produção de grãos: interações solo x planta x clima

Abstract

In Minas Gerais, soybean and common bean cultivation stand out within grain production systems, especially in areas managed under the no-tillage system (SPD), which contributes to soil conservation, nutrient cycling, and more efficient water use. However, despite the agronomic and environmental benefits of no-tillage, increased soil compaction has been observed, a phenomenon that impairs water infiltration, aeration, root development, and, consequently, crop productivity. This compaction is mainly caused by the repeated traffic of increasingly heavy agricultural machinery over time, as well as by difficulties in maintaining adequate crop residue and implementing crop rotations. Among mitigation strategies, mechanical interventions such as subsoiling and the use of cover crops stand out, as they promote the formation of stable soil aggregates and improve soil structure. In this context, the present study aims to evaluate the effects of soil compaction on soybean and common bean productivity under no-tillage, investigate its impacts on soil water conditions and micrometeorological variables within the plant canopy, and identify the most efficient decompaction strategy, considering the interactions among soil, plant, and environment. The field study was conducted in an experimental area in Lavras, Minas Gerais, with common bean (2024 season) and soybean (2024/2025 season). A factorial design was used, with three levels of compaction intensity and nine decompaction strategies. Growth, physiological, micrometeorological, and yield measurements were carried out at different crop growth stages. The results indicate that decompaction strategies and compaction intensity had distinct effects depending on the crop. Common bean was more sensitive to compaction compared to soybean, showing greater variations in growth, micrometeorological conditions, and yield. The combination of subsoiling with cover crops improved soil physical properties, increasing macroporosity and aeration, reducing bulk density and penetration resistance, resulting in higher productivity and water-use efficiency for both common bean and soybean, particularly under the treatment without additional compaction. For grain producers in Minas Gerais, adopting combined practices of subsoiling and cover cropping represents a promising strategy to mitigate the effects of soil compaction and enhance the performance of common bean and soybean under adverse climatic conditions.