W
ater is central to every-
thing that happens in turf
management. However,
water is an inherently
finite resource and its use
in the turf industry is coming under
increased scrutiny in parts of the west-
ern United States. In California, for
example, sports turf managers are being
mandated to reduce water use by as
much as 25% in the face of continuing
severe drought conditions.
As you know, too much or too little
can water can significantly alter playing
surfaces, complicating a turf manager's
already tough job and putting athletes
at increased risk for injury. So how do
turf managers balance the need for a
uniform, safe playing surface against
a mandate to use less water? Wetting
agents (or soil surfactants) can help.
IMPROVE
IRRIGATION EFFICIENCY
To understand how wetting agents
work, we first have to understand what
happens when water is applied to a
playing surface. It is our natural inclina-
tion to think that water applied on the
surface will penetrate uniformly and
without issue. However, the study of soil
science has shown that this is not always
the case. Over time, all soils develop
water repellency to some degree. Water
repellent coatings form on soil particles
from root exudates, fungal hyphae,
and decomposing organic matter—all
byproducts of growing healthy plants.
These water repellent coatings on soil
particles act as a barrier, making it
harder for water to penetrate and move
through soil evenly.
In highly managed turfgrass envi-
ronments such as sports fields, water
repellency tends to be more severe at
the surface and declines farther along
the soil profile. Typically, the top 3
centimeters of a coarse textured soil are
the most hydrophobic. This top 3 cm
is enough to significantly disrupt water
movement. Water repellency at the sur-
28 SportsTurf | October 2015 www.sportsturfonline.com
WETTING AGENTS
AND SPORTS TURF
S
FIELD SCIENCE
Editor's note: This article was supplied by Aquatrols.
A soil core shows varying degrees of water repellency
throughout the soil profile.
