FieldScience | By Andy McNitt, PhDmela J. Sherratt
Issues and technologies used
on NFL playing surfaces
I
'VE HEARD IT OVER AND
OVER AGAIN from those in the
turf business: "If I could mow at
one inch, I'd be able to have pristine looking turfgrass like in all
these NFL stadiums." I politely reply that if
those kinds of skills and knowledge existed
anywhere, there would already be lots of
smart people using them to improve these
surfaces.
Let's review a few facts that aren't always
in our frontal lobe while we watch an NFL
game from the comfort of our homes on a
late November Sunday.
First, it's November. It's getting seriously
18 SportsTurf | July 2013
cold now and the light levels are extremely
low. Think about the effects of "winter
play" on a golf course.
Yes, most of the NFL's northern fields
have an ethylene glycol heating system running under the sand rootzone. The heating
systems provide some benefit by extending
the growing season further into the fall and
limiting frost development on areas that require painting; however, light is still limiting. The sun is low in the sky and the
stadium seating is being placed as close to
the playing surface as possible. This means
very steep seats and significant shade. Yes,
south facing endzones are sometimes built
lower or more open but there are many
fields where the sun never hits the field
from the endzone through the 20 yard line
in November.
In the fall direct sunlight is very limiting
and if the heating system is used to push
the turfgrass excessively, the turf becomes
severely etiolated. Also, the heating system
can push moisture to the soil surface. In
theory, the ideal set up for an NFL football
game on a sand rootzone is to have ample
moisture in the rootzone but have it a little
dry in the top half inch or so. When the
heating system is running during cold
weather, moisture in the rootzone is vapor-
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