Where Do The Roots Go When There Is Too Much Water?
By Ty McClellan, agronomist, Mid-Continent RegionMay 19, 2011
Prolonged wet conditions in the spring hinder deep root development. A root system like this provides a lot of insurance for warm and cool season grasses prior to the stress of summer.
Talk about a case of the extremes! Much of the upper Mid-Continent Region experienced three days in the 90 degrees last week (including some portions of Kansas topping 100°F). This warm-up stimulated cool-season turfgrass growth in the northern areas of the region as soil temperatures finally rose into 60 degree range. Those with bermudagrass or zoysiagrass observed the first significant growth of the season. Fast forward to this week and nighttime lows have plummeted to produce consecutive mornings of frost slamming the brakes on warm-season turfgrass growth.
However, this update is really about another extreme occurring in the region – H20 (water). Portions of Illinois and Missouri have been inundated with rainfall during April and early May resulting in historic flooding. This certainly puts the decisions we make in the golf and turf industries into perspective. Meanwhile, most of Kansas and portions of Nebraska are in the early stages of drought. From a golf course maintenance standpoint, the preference is to control the water applied to a course so drier is nearly always better. For golf courses, the effects of drought can really only be seen in non-irrigated areas.
Since wet conditions cause many more turfgrass maladies than dry, this update focuses on courses suffering from too much H20. Briefly, waterlogged soils lead to:
- Lack of soil oxygen (i.e. anaerobic)
- Root dieback / shallow root system
- Reduced root uptake of nutrients and water
- Accumulation of toxic soil gases
- Reduced rate of natural organic matter decomposition
- Greater fungal disease pressure
- Increased compaction proneness to traffic
The most practical solutions to improve saturated soils: drainage and soil cultivation. The saying goes that there can never be enough drainage, and in sites where turf conditions chronically suffer from saturated soils improving drainage is key. Short-term, however, soil cultivation is needed as deeply and as soon as possible to improve soil oxygen content and promote rooting. Core aeration is generally best, but deep solid tining is effective as well.
For cool-season grasses, autumn and spring are the seasons to develop a strong root system, in part as preparation to survive summer heat stress when root mass declines naturally. So a shallow root system in mid-May only further jeopardizes its ability to survive summer. Even though mid-May generally marks the end for spring aeration of cool-season grasses, if turfgrasses on your course exhibit poor root development , aerating now while cooler weather persists is needed. Soil cultivation efforts performed now will increase the odds for cool-season turf survival come the dog days of summer. Fortunately, with warm-season grasses there is much less concern from stunted root systems in May because rooting will only improve as summer is their primary growing season and ideal timing for aeration.
SPECIAL ANNOUNCEMENT: Earn GCSAA education points for Turfgrass Advisory Service (TAS) visits. Golf course superintendents and assistants that subscribe and participate in a USGA TAS visit will earn 0.3 points for ½-day visits and 0.6 for full-day visits.
If you would like more information about a Turf Advisory Service visit, do not hesitate to contact either of the Mid-Continent regional offices: Ty McClellan at firstname.lastname@example.org or (630) 340-5853 or Bud White at email@example.com or (972) 662-1138.