Can you provide recommendations for those who are helping with the recovery of athletic fields following hurricanerelated flooding and damage ?

Q & A WITH DR . GRADY MILLER

– NC County Extension

As national news outlets have reported , there was significant personal and property devastation caused by recent hurricanes . Our thoughts go out to everyone impacted . This article is not intended to provide disaster recovery information for those most severely affected , but will offer advice for people who are managing less damaged fields .

The degree of turfgrass injury from flooding depends on turfgrass species , water temperature , duration of submergence and depth of submergence . Turfgrass can usually withstand submersion for up to 60 days when water temperatures are below 50 degrees , but may only survive a day or two when water temperatures are in the upper 80s or higher . If the turfgrass is submerged for more than a few days under water that is cloudy with silt , clay and debris , it is more damaging than if the water is clear . In addition , flood waters may contain toxic contaminants such as petroleum . These may cause longer-term problems because the contaminant may linger in the soil , impeding regrowth . And although it may seem minor , the lack of oxygen to the roots brought on by saturated soils may cause turf loss .

If the floodwaters deposited silts and clays on the surface , these should be removed with shoveling , scraping , power washing , etc ., as soon as possible . In some cases , debris and soil material can be blown off the surface with a blower . The airflow from the blower can also hasten the soil-drying process . If the grass does not begin to green up by the time the soil begins to dry out , it may be a sign that the turf is dead or so severely set back that regrowth is going to be very slow . Given enough time , bermudagrass will grow back from almost any flooding damage . But if the damage is more than just thin turf , and time is an issue , it may be better to start over completely .

The degree of turfgrass injury from flooding depends on turfgrass species , water temperature , duration of submergence and depth of submergence .

Since these conditions are occurring near the end of the bermudagrass growing season , it may be too late to get adequate new bermudagrass growth to cover severely damaged stands following renovation . If there are large bare areas , I would suggest that the fields be overseeded with ryegrass to stabilize the soil from further erosion and / or to provide a usable turfgrass surface in the spring . Overseeding with ryegrass will help absorb some of the extra moisture and the actively growing roots will help keep the soil pores open . If it was previously a tall fescue field , interseed with tall fescue seed rather than using ryegrass .

If the damage is not too severe , begin aerification once the ground can support an aerifier . This will help break up soil layers and get more oxygen into the rootzone . Do not expect much residual activity from previously applied fertilizer or preemergence herbicides . Fertilizer applications may benefit the turfgrass , but rates should be moderated due to the time of year . Floodwaters may have replenished your weed seed bank , which may translate to a need for greater postemergence weed control in the future .

If topsoil was eroded and replaced before renovation , there may be short- or longterm variation in turf growth and color due to differences in soil . Also , silt and clay deposits that were not removed may result in long-lasting visual and performance differences . Regular aerification and topdressing should address these problems over time . Turfgrass managers will need to honestly assess fields in late spring because field renovation may still be necessary . SFM

Grady Miller , Ph . D . Professor and Extension Turf Specialist North Carolina State University

Questions ? Send them to Grady Miller at North Carolina State University , Box 7620 , Raleigh , NC 27695-7620 , or e-mail grady _ miller @ ncsu . edu

Or , send your question to Pamela Sherratt at 202 Kottman Hall , 2001 Coffey Road , Columbus , OH 43210 or sherratt . 1 @ osu . edu

50 SportsField Management | November 2024 sportsfieldmanagementonline . com