Water Retention and Availability in an Ultisol Under an Integrated Crop–Livestock–Forest System in the Matopiba Region, Brazil

Soil water retention and availability are influenced by intrinsic soil properties, management practices, and climate regimes. This study aimed to evaluate water retention and availability in an Ultisol under different integrated production systems in the Brazilian Cerrado. The systems analyzed included Crop–Livestock Integration (CLI), Livestock–Forest Integration (LFI), Crop–Forest Integration (CFI), no-tillage (NT) and native Cerrado vegetation (NV). Disturbed samples were collected for physical and chemical characterization, while undisturbed samples were used to determine water retention curves at depths of 0.00–0.10, 0.10–0.20, and 0.20–0.40 m. From these curves, water availability, pore-size distribution, differential log-pore-radius curves, most frequent pore radius, and relative hydraulic conductivity were estimated using the Mualem–van Genuchten model. Confidence intervals were used to evaluate differences between retention curves. The CLI system showed lower water content at saturation (14–30%) and field capacity (10–20%) compared to CFI, LFI, and NT. The NT system exhibited higher water availability across all layers (28, 48, and 46%, respectively) than CLI. Alterations in pore structure, likely due to the short integration period and monoculture history in CLI, resulted in lower water retention. Conversely, CFI, LFI, and NT showed higher retention and availability, attributed to higher organic matter content and more stable structural pores. Integrated production and no-tillage systems, especially when adopted long-term, enhance soil water retention and availability in the Brazilian Cerrado.