Precision and blanket aerification effects on spatial variability of surface hardness in turfgrass sports fields

Abstract

Sports field surface hardness is spatially and temporally variable, and evidence suggests this variability can influence athlete perceptions, performance, and injury risk. Management strategies addressing within‐field variability, rather than mean hardness alone, are therefore needed. This study evaluated blanket and precision aerification programs for reducing spatial variability in surface hardness of two Tifway 419 hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] recreational sports fields with loamy sand and sand‐capped rootzones in College Station, TX in 2021 and 2022. Treatments included an non‐treated control, annual blanket, annual precision, triannual blanket, and triannual precision aerification programs using solid tines. Blanket aerification was applied to entire plots, while precision aerification targeted areas exceeding the median surface hardness, identified using Bayesian kriging of weekly georeferenced Toro Mobile Tester data. Spatial variability was assessed using the coefficient of variation and geostatistical total sill, each modeled with mixed‐effects frameworks. On the loamy sand, the annual precision and triannual blanket aerification treatments reduced mean surface hardness relative to the control, whereas no treatments significantly affected mean surface hardness on the sand‐capped rootzone. No coefficient of variation comparisons reached significance on either field. Treatment effects on spatial variability were more evident in the geostatistical analysis, where precision treatments reduced total sill on the loamy sand, while on the sand‐capped field only the triannual blanket treatment reduced total sill, and triannual precision increased spatial structure relative to other aerification treatments. Treatment responses were inconsistent across rootzone types, suggesting rootzone characteristics may matter more than application strategy in aerification program design.