INFIELDS capacity , and decrease the stability of the infield profile . Calcined clay , expanded shale , or a combination of both should only be applied to the top surface of your infield profile at an 1 / 8-inch depth ( no more than 1 / 4 inch ) to improve the sliding surface and moisture management .
Using calcined clay and / or expanded shale as a topdressing has become recognized as a best management practice in recent decades . However , there are still stalwarts out there who cling to the old tilling method . Changing the process throughout an entire industry will not happen overnight . The use of the term “ conditioner ,” and the continuing message to use calcined clay and expanded shale as an “ amendment ” to improve your infield profile is still common . Recommendations of as much as 1,800 lbs ./ 1,000 ft 2 are still common . The question is how can calcined clay be marketed as a conditioner for both infield skin profiles and rootzones when the objective for the performance of each are opposite ?
If your goal is to improve your infield soil , the best approach is based upon science . Collect and submit a soil sample to a professional laboratory for a particle size analysis . This is the blood test for infield skin material . The results will show the proportion of sand , silt and clay in the infield skin . At this point , adding the right soil as an amendment can alter the makeup of the soil and correct any deficiencies in its texture . This approach permanently modifies the soil and can be measured . Tilling calcined clay or expanded shale cannot correct the soil texture in ways that are beneficial to the performance of an infield skin .
One common issue with calcined clay is the breakdown of the particles due to the abrasive actions of dragging , rolling , normal play and other maintenance tasks . Expanded shale resists breakdown due to the natural hardness of the raw material , which is further enhanced through the heating process of it during production of the product . When calcined clay does break down , it tends to turn to a powder that acts much like a silt layer on the
surface of the infield . As this “ silty ” layer accumulates on the surface , it can create very dusty conditions when dry and slimy conditions when wet . At this point , the only fix is to remove the top 1 / 2 inch to 1 inch of contaminated material and replace it with new infield mix .
Research the calcined clay products available on the market to find the most durable . The quality of calcined clay increases as you increase the temperature at which it is baked . Those that are baked just enough to calcine it are subject to more rapid breakdown on the field surface than those that are baked to the upper end of the calcining process . Those calcined clays will be more durable and break down at a slower rate — and therefore last much longer on the infield surface . You will find there are sizable differences between the brands on the market .
Sports field managers should look at topdressings as tools in a toolbox . Today ’ s various offerings of infield topdressing materials have distinct different modes of action , and sports field managers need to understand the benefits of each of these materials . They can then decide which material ( s ) they want to use — either alone or combined with each other to craft the performance they want for the surface of their infield . SFM
Luke Yoder and Paul Zwaska are members of the DuraEdge Products Business Development Team , which features more than 125 years of combined professional groundskeeping experience . Yoder is former head groundskeeper for the Pittsburgh Pirates and San Diego Padres , and Zwaska formerly served as head groundskeeper with the Baltimore Orioles . sportsfieldmanagementonline . com December 2023 | SportsField Management
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