The Balancing Act

What you are seeing here are earthworm castings in the 5th fairway. You probably have noticed these tiny patches of soil on fairways, 2,4,5 & 6.
If you remember your biology classes in school, you remember that earthworms are good for the soil and plant growth.They benefit the soil by providing simple aeration as they feed on organic matter. Organic matter is typically found close to the surface in the thatch or mat layer. When the worm processes the soil, it leaves behind these castings of soil. This is where they can be detrimental to a golf course.
These castings can impede ball roll and playability. They can also create problems to mowers when the soil cakes on and disrupts their operation.
Managing these holes is certainly a balancing act. There is so much rock beneath these fairways that the root structure is limited in depth. These fairways require light and frequent irrigation as well as carefully timed fertilizer applications. We also use growth regulator chemistry to promote lateral growth and increase density.

When conditions become dry on the course these castings can become more noticeable. Balancing irrigation is certainly a challenge. Often times these areas require hand watering to efficiently irrigate where it is absolutely necessary. Pictured here are two staff members watering drier areas on the course. When hand watering, the staff will probe the soil to determine if the soil needs moisture or not. The new irrigation system has certainly helped decrease hand watering, but if you are not hand watering, you are over watering.

How do you prevent earthworm castings and why don't you see them on the greens? Studies have shown that earthworms are very sensitive to sandy soils. The soil profile in greens mostly consist of sand and some organic matter. The sand is abrasive and is uncomfortable as they move through the profile. Greens typically have less organic matter to feed on compared to a fairway.