Too much of anything is rarely a good thing — this is the certainly the case with turfgrass irrigation.
Healthy stands of turfgrass rely on just the right amount of water. With that being said, too much water can be just as bad as not enough, albeit for different reasons. According to Dr. David Gardner, assistant professor of turfgrass science at Ohio State University, “not enough water is a problem that can be dealt with pretty easily if you have access to irrigation. Too much water is also an issue and a bit more complicated to deal with. Of course, this is more of an issue on soil-based fields, particularly those with heavy clay.”
The amount and frequency of water needed to supply an athletic field depends on several factors, including the type of turfgrass being used, soil texture, soil structure, climatic conditions and degree of compaction.
According to the Sports Turf Managers Association (STMA), overwatering causes:
- Rapid turf growth
- Shallow rooting
- Decreased tolerance to weed and pest invasion
- Reduced tolerance to heavy traffic
- A surface that is more prone to compaction by athlete traffic and mowing equipment
- Increased leaching of nutrients
In addition, maintaining a wet soil is only acceptable under certain conditions, such as on newly seeded areas.
Further reading: SFM talked to several experts about how sports turf managers can implement efficient irrigation practices.
“Whenever possible, a field that’s too wet should be closed,” Gardner says. “Many of the techniques attempted by sports turf managers to accelerate drying only exacerbate the issues that caused the problem. For example, when dealing with standing water, it may be tempting to try to sweep or push it onto an adjacent surface. But this can be very damaging to the soil structure, which makes it drain even more slowly. A pump can be used to remove standing water, but this only accelerates drying. The field will remain saturated for a period of time, and use under these conditions degrades the soil structure.”
When evaluating irrigation practices, it’s imperative to evaluate the system that delivers the water. Not all systems are created equal, and even the best irrigation system needs to be supplemented with hand watering. If you aren’t hand watering at some point during the growing season, you’re likely overwatering. The performance of irrigation heads should be monitored over time to be sure that water is applied as efficiently as possible. One way to ensure that your irrigation system is doing its job is to conduct an irrigation audit.