SOIL HEALTH
Building top-tier sports turf from the soil up
For insight into soil health, SportsField Management magazine recently spoke with Rebecca Knapp, CSFM. A Penn State Turfgrass alumnus, Knapp has prior experience in MLB, MLS, NCAA and MiLB. Knapp is also a member of the SFMA Editorial Committee.
SportsField Management( SFM): How can we effectively assess and monitor soil health in sports fields beyond standard soil nutrient testing? Knapp: Soil health goes far beyond NPK values. While nutrient testing is essential, we need to gain an understanding of what’ s happening below the surface if we want resilient, high-performing fields, especially under the stress of play and tight turnaround schedules.
One of the most critical challenges is soil compaction. Regular use of a penetrometer or a shear strength tester— especially in high-traffic zones such as goal mouths, position areas and sidelines— can provide real-time insights into rootzone resistance and whether aeration and topdressing programs are effective.
All photos provided by Arborjet | Ecologel
It is also important to monitor organic matter levels through annual physical soil testing not just for thatch, but for how it affects water infiltration and rooting. Caution must be taken when applying compost to sand-based fields. If organic matter exceeds 3 %, water infiltration and percolation rates will be restricted.
Soil biology deserves a greater focus. Microbial activity or biomass testing are available and will present soil respiration. Results will vary with seasonality because soil temperatures and moisture levels affect microbial activity. Inputs such as carbon-based fertilizers, biostimulants, and molasses-based fertilizers are solutions that can be implemented to support beneficial microbial life.
Develop a consistent visual inspection routine. In addition, use a soil probe to assess rooting depth and evaluate soil moisture. Smell the soil, as healthy soil will smell earthy. These observations can help validate lab data and assist with field management decisions.
SFM: What are the best practices for improving soil structure in high-traffic areas such as goal mouths and sidelines? Knapp: With high-traffic zones like goal mouths, sidelines and player bench areas, the key is being proactive and layering multiple strategies together.
Aeration remains an effective approach. Depending on available field recovery time, hollow- or solid-tine aeration can be effective. Aeration will relieve compaction and open up space for air and water to enter your soil profile and provide space for new root growth.
Topdressing complements this process, and is best managed through consistency. Use a sand blend that matches the existing rootzone. Light and more frequent applications tend to deliver the best results to maintain a uniform surface.
22 SportsField Management | December 2025 sportsfieldmanagementonline. com