INFIELDS the plastic limit . Stiffness is a measure of the force needed to deform the soil . An ideal infield soil retains a plastic and stiff consistency , even under hot sun or during a rain game . Designing these types of mixes is a current research topic at Penn State . We recently created a laboratory method to measure the cleat-in / cleatout effect . We are using the method to test infield mixes containing various clay minerals , since these respond differently as the soil wets or dries . Thanks are extended to the PA Turfgrass Council , KAFMO , and the SAFE Foundation for supporting the project .
On a synthetic turf infield “ skin ,” surface deformation happens differently . The fibers ( rather than soil water ) reduce the rotating and sliding of infill particles . The sand : rubber ratio and particle size distribution of the infill may also affect performance .
SUMMARY Ball response can be managed intuitively , but it helps to consider the underlying physics . Consistency is most important . What infielders experience as speed is a combined effect of pace , bounce and spin . Conditioners reduce the effects of ball spin by lowering surface friction . The soil must be both stiff and plastic to achieve the coveted corkboard . Future research could define new playability measures and how to achieve them . SFM
Evan C . Mascitti is a Ph . D . candidate in soil science at Penn State . He previously worked for several years as a grounds manager in professional baseball .
Andy McNitt , Ph . D ., is a professor of soil science , and director of the Penn State Center for Sports Surface Research ( www . ssrc . psu . edu ).
REFERENCES
Adams , W . A ., S . W . Baker , D . M . James , and R . J . Young . 2005 . Measuring and Modelling the Bounce and Pace of County Championship Cricket Pitches . International Turfgrass Society Research Journal 10 ( 1021-1026 ): 1021 – 1026 .
Brosnan , J . T ., and A . S . McNitt . 2008a . Surface Conditions of Highly Maintained Baseball Fields in the Northeastern United States : Part 1 , Non-Turfed Basepaths . Applied Turfgrass Science ( April ). doi : 10.1094 / ATS-2008-0520-01-RS .
Brosnan , J . T ., and A . S . McNitt . 2008b . Surface Conditions of Highly Maintained Baseball Fields in the Northeastern United States : Part 2 , Synthetic versus Natural Turfgrass . Applied Turfgrass Science ( April ): 8 . doi : 10.1094 / ATS-2008-0520-02-RS .
Brosnan , J . T ., A . S . McNitt , and T . J . Serensits . 2011 . Effects of surface conditions on baseball playing surface pace . Journal of Testing and Evaluation 39 ( 3 ). doi : 10.1520 / JTE103215 .
Daish , C . B . 1972 . The Physics of Ball Games . The English Universities Press , London .
Goodall , S . A ., K . Guillard , W . M . Dest , and K . R . Demars . 2005 . Ball response and traction of skinned infields amended with calcined clay at varying soil moisture contents . International Turfgrass Society Research Journal 10 : 1085 – 1093 . sportsfieldmanagementonline . com March 2021 | SportsField Management
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