Testing Your Mix - What Do the Results Mean? - SILT-TO-CLAY-RATIO
This is the fourth of 4 posts explaining in detail what each part of an infield mix test result includes and what it means to your infield.
Today we discuss silt to clay ratio (SCR). SCR is a basic way to allow a ratio to better forecast how a material will perform. How do you obtain a SCR? Simply divide the silt into the clay. A SCR for any infield mix at any level of play should fall within the .5 - 1 range. Along with sand sizing of your infield material, the SCR or the material will determine how well the infield mix will play in all weather conditions. Let’s look at 3 different types of SCR’s and how the infield perform.
Low SCR .1-.5 - A low SCR is common in mixes in Florida. Since silt is the “bridge” that holds/binds the sand and clay together, low SCR infield have a tendency of “blowing apart” or separating during play. If you are managing an infield that has large “chucks” of infield mix when the players are playing on the infield it is probably due to a low SCR.
Balanced SCR .5-1.0 - A balanced SCR has slightly more clay than silt or equal part clay and silt. Due to this, the infield is “balanced.” Simply, this infield provides a surface that will allow for a cork board type feel while also allowing for “cleat in cleat out” play.
Elevated SCR Higher than 1.0 - An elevated SCR can lead to a number of different playability issues for infields. A slightly elevated SCR (1.0-2.0) can often play well if managed properly. When materials have a SCR above 2.0 issues set in. Keep in mind a SCR at 2.0 means there are two times the amount of silt to clay in the material. Infields with high SCR have a dust layer and on the surface and a hard pan underneath. Is your infield very dusty when dragging? Does your infield look like this after a rain event?
If so you have a high SCR.The infield will play “well” only for a short period of time.Often end users think a high silt infield is very high in clay.When they get the results back they a surprised to say the least!
As you can see a 70/30 infield mix can mean many different things. Make sure to TEST THOSE INFIELD MIXES!
Co-founder and partner of J&D Turf. A sportsturf junkie, I cut my teeth at Victory Field with the Indianapolis Indians maintaining the playing surface at what has been dubbed "The Best Minor League Ballpark in America." From intern, to assistant to head groundskeeper over 10 seasons, I was director of operations for the team before realizing sportsturf was my passion, baseball was merely the game.
My bachelor’s degree in sports management from Marian University and a degree in turfgrass science from Purdue University serve as the initial credibility with clients ranging from university to K-12 administrators, parks and rec officials, and maintenance crews to my friends with their own fields in the Major Leagues.
The "Smart Turf" blog is my way of sharing my experiences as consultant, groundskeeper and business owner with the larger sportsturf community. There was a day early in my career that I'd joke that I live to make tall grass short. Given the expanding horizon of this profession over the last decade, I've come to realize and respect it as much more.