Improvement of Baseball Infield Mixes

By Dr. Andy McNitt and Mr. Evan Mascitti

Intro: Much of a baseball game is played on the infield skin. Players expect the bare soil to provide firm footing and consistent ball bounces. An ideal infield soil retains a firm yet forgiving consistency across a wide range of moisture levels. This trait allows the game to continue during rain and prevents the field from getting too hard as it dries out. It also gives the field manager a wider target to hit when hand-watering. Players’ cleats can easily penetrate the soil, but the cleats do not remove chunks and leave only small indentations. This is known as the “cleat-in, cleat-out” effect (Fig. 1)

FIGURE 1 A: Clean cleat-in, cleat-out

FIGURE 1 B: Chunk-outs

Objectives: Our research goal is to measure the “cleat-in, cleat-out” phenomenon with a novel lab device (Figure 2). The intent is to develop mixes with fewer “chunk-outs” and extend the range of water content where the mix holds together without becoming too soft. In addition, the project will determine which clay minerals are best suited for this use and allow the properties of a sand-clay blend to be predicted from lab testing.

This project is being funded jointly through grants from the Pennsylvania Turf Council, the Keystone Athletic Field Manager’s Organization, and a competitive grant from SAFE, the Foundation for Safer Athletic Fields www.safefields.org

FIGURE 2: Chunking device under construction