Field Conditioners & Mound Clay

Field conditioners are unique soil mixes that help keep the skinned areas of baseball and softball fields safe, level and playable. They manage moisture, prevent compaction and provide players with an even surface to run, slide and field on.

Mound clay is heavier, high-clay material for pitcher’s mounds, hitter’s boxes and bullpens. This post details what field conditioners are, why they’re important, the different kinds one can get, and how to decide which is best for the needs on the mound, in addition to how one would prepare mound clay for the season, and maintain it throughout the year.

Field Conditioners

Infield mixes are blended with field conditioners to control moisture and stability. They soak up additional moisture after a rowdy rain, but also release it back into the soil as things begin to dry, limiting puddles and dust. They even maintain the surface soft enough that it reduces injuries, but firm enough to retain its shape even after heavy use.

Proper moisture management keeps play on time and fields safe. When the skin dries all the way, it gets hard and dusty and breeds bad bounces, and clouds the air. If it remains too wet, the surface gets slippery and there is a danger of creating holes. Field conditioners level water so grounds crews can keep moisture depths even at two to four inches.

Main Types of Field Conditioners

There are four basic types of conditioners. All of them perform best in various climates, budgets and maintenance schedules.

• Calcined Clay: Black tops use calcined clay, which is clay that has been heated to a really high temperature. It forms porous granules that soak up water and retain it until the field dries. This variety is the standard choice for professional and collegiate use as it yields moisture retention over several days, all without the use of artificial additives.
• Expanded Shale and Clay: Shale and clay are fired together to create lightweight, ceramic-like pellets. The pellets are non-compressing and remain loose while providing stability under foot after extensive compacting foot traffic. They provide for natural colors that complement infield skin, with added benefit for drainage in wetter climates.
• Brick Dust: Ground brick can also be used as a low-cost conditioner. It accepts water well and yet can become quite firm when too much is applied. Its best use is as a quick fix or in lower-play areas.
• Diatomaceous Earth: It’s a soft siliceous, rock-like mineral, ground into powder. It absorbs water readily but deteriorates with heavy use. The surface needs to be replaced often to preserve its stability.

Mound Clay

Mound clay is a specialized conditioner with a 20% clay content. It is screened to eliminate extraneous stones, and the resulting gritty, stiff blend is used as a medium. When dampened and compacted, a mound makes a firm, durable hill that will not crumble even when players make sharp, aggressive slides.

Benefits of Mound Clay

Mound clay has its own unique benefits for high-wear areas:

1. Firmness: It packs well to forestall deep footprints and ruts.
2. Moisture Retention: Clay goes in wet, stays in place and insists that water not run off.
3. Shape Holding: After being set and compressed, it holds the exact slope and height required for mounds and batters boxes.
4. Repair Ease: Low areas and holes can be patched by scattering new, wet clay on top and re-compacting.

Choosing the Right Mound Clay

The clays are not all the same as the mound clays. Field management needs to come to terms with:

• Clay Content: The more clay, the better compaction and the slower the drying.
• Particle Size: Granules are equal in size so avoid loose pockets.
• Color Options: Available in red or brown to match existing infield skin.
• Supplier Support: Reputable suppliers offer technical data sheets, coverage calculators and application diagrams.

Preparing Mound Clay for Use

The better the preparation the more stable the mound is:

1. Hydration: Sprinkle a little on any dry clay a minimum of 24 hours before applying the build-up. Mix the paste around to even out the moisture.
2. Mixing: Break up lumps and mix until it’s the texture of wet beach sand, too wet and it will slump; too dry and it will crumble.
3. Screening: Sift the material through a 1/4″ screen and discard large pieces.

Building and Compacting the Mound

Layering and compaction are key to a long-lasting mound:

• Only put in clay in 1–2-inch lifts, not all at one time.
• Compact each lift evenly, with a hand tamper or small plate compactor.
• Use a hoe and straightedge for shaping the slope to regulation after it has been compacted.
• Spray the top surface lightly before each game to maintain workability and avoid cracking.

Regular Maintenance Practices

Ongoing care keeps the mound clay in top condition:

• Inspect after each practice or game for low spots, tears or washouts.
• Patch holes in untilled soil with small amounts of moist clay and reconsolidate them.
• Keep the edges of the pitcher’s plate and batter’s box clean and well defined in order to prevent the accumulation of mud.
• Rebuild or resurface prior to heavy use seasons to ensure proper slope and firmness.

Storage and Handling Tips

Correct preservation of the pile clay keeps it in usable condition for:

• Keep in closed bins or pallets under a tarp with no caking or mold.
• Dated resources should be used before new resources and should be kept sealed until used.
• If the clay has taken in rain or moisture, spread it out to dry or mix with new material.

Environmental and Safety Notes

Mound clay products are generally nonreactive and free of toxic substances. However:

• Stir under moist conditions or spray with water during application to lower aerosol production.
• Workers should use gloves and a basic dust mask if the levels of dust are too high.
• Do not wash a bunch of clay into the storm drain, sweep it back into the storage mound or mix mounds.

Conclusion

Field conditioners are a must for high traffic skinned areas of the field. When properly selected and installed, mound clay forms a solid, level and stable surface that resists wear and tear from game play. Knowing the different types of conditioners, how to properly prepare and compact the clay, and effective storage and maintenance techniques can help grounds crews maintain pitcher’s mounds, batter’s boxes, and bullpens in top condition throughout the season.