Penetration resistance: An effective indicator for monitoring soil compaction in pastures

•Soil penetration resistance can be effectively estimated by the field penetrometer.•Nitrogen fertilization increases soil load bearing capacity through animal trampling.•Preconsolidation pressure can be estimated by penetration resistance. Compaction, often promoted by animal trampling and loss of forage plants, is a main cause of soil degradation in pastures. Our objectives were to evaluate various pasture management strategies for maintaining soil physical quality and to evaluate penetration resistance as an indicator of soil compaction in pastures. For each strategy, the goal was to maintain or extend least limiting water range (LLWR) and soil compressive behavior. Three treatments [Brachiaria (Br); Br intercropped with forage peanut (Arachis pintoi) (Br + L); and Br fertilized with 150 kg N ha−1 (Br + N) were compared to a native forest reference (Ref) in four pasture areas in Brazil. Pasture management strategy did not significantly influence LLWR, but the Br + N treatment resulted in greater soil degradation evidenced by a lower LLWR. These results are useful for improving pedotransfer functions and decision aides that predict physical–mechanical soil quality, impact on vegetative cover, and the appropriate animal carrying capacity for specific pasture areas. They also confirm that soil moisture and penetration resistance are effective for calculating load carrying capacity, factors that help with decision making regarding implementation of new management practices in pasture areas.