Spatial Variability of Soil Physical Properties Across Golf Course Fairways

Water management in turfgrass systems is critical in semi-arid regions, where groundwater, such as that from the Ogallala Aquifer, sustains both agricultural and recreational landscapes, yet faces depletion challenges. Water quantity and quality concerns are elevated in urban areas that experience increased population and higher potable water demand. Precision technology applied across agriculture production systems have altered management of key plant inputs by recognizing the specific rates and locations of highest demand. Turfgrass systems are intensively managed with similar inputs, but it has not been common to utilize precision techniques to prescribe application of inputs to optimize sustainability. This study investigated the spatial variability of Plant Available Water Content (PAWC) and the S index (a soil physical quality indicator) across select golf course fairways, specifically at the Rawls Golf Course and Amarillo Country Club located in the Southern High Plains of Texas. Using principles of Precision Turf Management (PTM), this study aims to assess spatial variability in soil physical properties that impact water retention and distribution, offering insights into site-specific irrigation strategies that enhance turf performance without compromising playability. Through extensive sampling across three golf course fairways, we calculated PAWC and derived the S index using water retention curves modeled via the van Genuchten equation. Additionally, laboratory techniques were used to determine bulk density, texture, organic matter, and near saturated conductivity of soil samples. Field-based measurements of volumetric water content, penetration resistance, and normalized difference vegetation index were also collected. Ordinary kriging was employed to spatially analyze and interpolate PAWC and S index distributions, revealing notable patterns. While Rawls Golf Course 14 exhibited a pure nugget effect for the S index, indicating a total absence of spatial correlation, other fairways were well fitted with spherical variograms and exhibited with low nugget variance and ranges of spatial dependence between 25 and 28 meters. Bulk density (negative) and soil porosity (positive) were highly correlated with both PAWC and S index for most sampled fairways. Furthermore results showed strong positive correlation between PAWC and the S index. This work highlights the importance of spatial variability analysis in PTM, providing a foundation for efficient water management strategies within turfgrass systems. Findings underscore the potential for tailored interventions that maintain fairway quality while conserving water resources, crucial in regions with limited and declining groundwater reserves.