ESTABLISHMENT OF FOOTBALL TURF
ISSUED: 3-79
REVISED:
A.J. Powell, Jr.
Department of Agronomy
Turf on all athletic fields should provide
playing safety, good footing, and a pleasing appearance. It should be resilient
enough to cushion falls and prevent abrasions, but also firm enough to
permit good surface stability. In order to establish a quality field, proper
construction and establishment are necessary.
There are many construction techniques
used in building athletic fields, depending upon available capital and
intended use. The following would be considered minimum recommendations.
Orientation
In most situations, the field should
be orientated with the main or long axis running approximately north and
south.
Excavation
Before the area is graded or contoured,
the top 12-18 inches of topsoil should be removed and stockpiled nearby.
If the topsoil is unsatisfactory, the field may be built over the existing
soil level. Avoid working soil while it is excessively wet.
Contouring the Subgrade
In order to remove excess water from
the playing field, it is absolutely essential that an 18-inch crown be
established down the center of the field, along with necessary drainage
down both sidelines (see Figure 1). In order to remove excess water from
the sidelines, corregated plastic drainage lines with pea gravel backfill
or catch basins should be constructed. The drainage lines should be placed
within slight swales running lateral to the sidelines.
With a properly constructed 18-inch
crown, a tile drainage system under the entire field is not necessary unless
underground seepage is a problem. Surface compaction usually renders a
general tile system ineffective. (Since the high center crown of football
fields makes side shots in soccer difficult, it is not advisable to use
the same field for both sports. Soccer fields should not have more than
a one percent grade from the center of the field to the edges.)
Irrigation Installation
Although irrigation is not an absolute
necessity, it is a prime consideration in maintaining a quality, dense
turf. It should be installed immediately after the subgrade is contoured-not
after the topsoil has been replaced. Irrigation systems vary from padded
pop-up types of sprinklers, spaced uniformly over the entire playing area,
to occasional outlets placed near the sidelines. Traveling sprinklers with
hose connections to perimeter outlets provide very satisfactory irrigation.
These apply water over rectangular areas and can easily be adjusted to
conform with wind direction and velocity. Lower initial costs of perimeter
outlets may prove more expensive in the end if considering efficiency and
additional labor.
Selecting and Spreading the Topsoil
Since soil compaction is the most common
cause of poor turf on athletic fields, a sandy loam topsoil is preferable
(but is not always available). If the topsoil that was removed initially
was a sandy loam (or even a silt loam), it should be evenly spread (by
the use of grade stakes) over the subgrade to depths of approximately 12
inches. This may require 2000 cubic yards of suitable soil.
Trying to make good topsoil from existent
heavy clay soils is generally not economically feasible. Such modification
requires uniform incorporation of large amounts of specially selected sand.
If the wrong soil-sand combination is utilized, the mixture may set up
like concrete and be very unsuitable for an athletic field. Various types
of organic materials are somewhat effective in reducing soil compaction.
Raw or cultivated reedsedge peats are helpful when 1 to 2 cubic yards (per
1000 sq. ft. of surface) of the peat is thoroughly mixed into the surface
3-4 inches. Sewage sludge, seed hulls, and well-rotted sawdust are somewhat
less effective and should be applied at much higher rates, depending upon
their moisture content and other factors. However, there is no easy or
cheap substitute for a good topsoil.
Fertilization and Liming
Lime and fertilizers should be added
just prior to final seedbed preparation. Soil samples should be taken from
8 to 10 locations throughout the field. One to two pints of the composite
sample should be taken to the local agricultural Extension Agent for analysis
and recommendations. (in situations where this is not possible, apply approximately
one to two tons of lime per acre and 800 pounds of 10-10-10 fertilizer.)
The lime and fertilizer should be worked into the surface 3-4 inches.
Final Seedbed Preparation
The field should be smoothed and contoured
to meet the 18-inch crown specification. This may be accomplished by dragging
the field with a section of chainlink fence or steel drag mat. Be very
careful not to drag soil away from the crown. The soil should be firmed
with equipment such as a cultipacker prior to planting.
Selection of Grass
There are no grass species that will
provide a trouble-free turf in the transitional climatic zone of Kentucky.
Our best choice appears to be Bermuda grass or tall fescue. Some limited
use of Kentucky bluegrass is often feasible.
Bermuda grass
Because of its ability to be mowed
very close, and its very tight, sod-forming characteristics, Bermuda grass
is probably the most resilient of the grasses that can be used in Kentucky.
There are several major problems with Bermuda grass: (1) The biggest problem
is its tendency to winterkill. (2) It becomes dormant (turns brown) during
the football season. (3) Bermuda grass is very wear-tolerant during its
normal growing season (May-September), but can be severely damaged by late
season wear. (4) In order to repair most varieties of Bermuda grass, vegetative
re-establishment is necessary. This can be a very time consuming job every
spring if winterkill or heavy fall use has severely damaged the turf.
Varieties which may be considered for athletic field use include:
Quickstand and Vamont- are to be more winterhardy than other
commercially available varieties. Their texture is slightly finer than
common Bermuda grass. It must be vegetatively planted as sprigs or sod.
Common Bermuda grass- can be seeded but it is very likely to
winterkill. It spreads rapidly and generally has good sod-forming characteristics.
Tall Fescue
This is probably the best adapted turf
specie in Kentucky. Winterkill and fall dormancy are not problems of tall
fescue; furthermore, it can be seeded. Major problems with tall fescue
include: (1) Because it is basically a bunch-type grass, it does not have
great resiliency. (2) Its minimum mowing height is between 1 1/2-2 1/2
inches. (3) It has very slow lateral spread and will not fill in areas
previously damaged.
Varieties- Many new turf-type
varieties of tall fescue are available. They have a finer texture, a darker
green color and more dense cover than KY 31 and other pasture varieties.
Kentucky Bluegrass
Because it is slow to establish and
does not have good wear tolerance, Kentucky bluegrass is not generally
recommended for athletic fields. However, in situations where an immediate
turf is needed within four to six weeks, Kentucky bluegrass may be sodded.
A two to three year old Kentucky bluegrass sod is much more resilient and
wear-tolerant than a one year old seeded stand of Kentucky bluegrass. As
the sod is thinned by traffic, the new fine-leaved perennial ryegrasses
may be easily inter-seeded in order to obtain quick aesthic quality and
increase the overall wear-resistance of the turf.
Planting
Football fields are established by
seeding, sprigging (of Bermuda grass), or sodding.
Tall fescue sod is not always availableor
affordable in Kentucky, and therefore it is usually seeded. Use a seeding
rate of 200-250 lbs. of Certified seed per acre. (The playing area between
goal posts is approximately 58,000 sq. ft., or 1.3 acres.) The best time
to seed tall fescue is between mid August and mid September. Heavy traffic
should not be permitted on the young turf until the following fall. Tall
fescue can be seeded in late February or March but it will not mature in
time for heavy fall traffic.
Common Bermuda grass sod is generally
not available. Although not very winter-hardy, common Bermuda seed is available
and it should be seeded at approximately 80 lbs. per acre (hulled seed).
Seeding should be done in May or early June and traffic should not be allowed
on the turf until fall.
Quickstand and Vamont Bermuda grass
may be established by sod or sprigs. When sprigging, approximately 400-600
bushels of sprigs per acre are necessary in order to obtain quick and satisfactory
cover. The sprigs may be uniformly broadcast over the surface and then
lightly disked into the top inch of soil. Sprigs should not be covered
deep. Sprigs may also be planted with a specially designed sprig-planter
or a hydro-mulching machine. Regardless of planting method, after the sprigs
are in good soil contact, the seedbed should be firmed with a cultipacker
or roller. It is of utmost importance that the soil surface must be kept
moist for 14-21 days after planting. This may require two to four light
irrigations per day. The sprigs should be planted during May or early June
and traffic should be eliminated until September.
If play is to begin soon after the
field is completed, sodding may be the only choice. A good sod, properly
placed and managed, will "knit" and be ready for use in four to six weeks.
Sod, rather than seed, should be used for patching thin or disturbed areas
unless the field can be kept out of play for several weeks. Seedbed preparations
for sodding should be the same as for seeding or sprigging.
Kentucky bluegrass sod is generally
available throughout Kentucky but should be carefully selected in order
to get a dense, weed-free turf. (The playing area between goal posts requires
approximately 6,400 sq. yds. of sod. Most often, however, additional sod
is needed for the sidelines.)
Mulching
Mulching with a weed-free straw helps
new seedings by preventing erosion and preserving soil moisture. It should
be applied at an approximate rate of 40-60 bales per acre. Other wood-fiber
mulches are suitable but must be applied with a hydro-mulcher. Do not remove
the mulch after germination.
Irrigation
Regardless of the establishment method,
the seedbed (or sodbed) should be kept moist until the grass is well established
and rooted.
Weed Control
It is almost impossible to establish
a good turf without chemical weed control. After a late summer seeding,
a late fall or early spring application of a broad-leaf weed herbicide
and a spring application of a crabgrass preemergence herbicide is usually
needed for tall fescue establishment. Two or three repeat treatments of
a postemergence crabgrass herbicide are almost always needed when establishing
Bermuda grass from seed or sprigs. If not applied, the crabgrass will often
outgrow the Bermuda grass.
For information on proper weed control
in turf, request AGR-72 from your local Extension agent.