myth may have something to do with the fact that a large
amount of water is used immediately after the sod is installed.
Watering will ensure close contact between the sod roots
and soil, and will prevent the sod from drying out. Once
the sod roots have firmly grown into the soil, then less
water is needed. This usually takes about two to three weeks.
In comparison, seeding requires very high quantities of
water to achieve germination and establishment. Multiple
daily applications are needed to maintain adequate moisture
to prevent the seed from drying out quickly on bare soil.
Seeding usually takes several months to establish a turf
and thus more water is needed before the turf matures. Therefore,
sod has the lowest overall water requirements of all lawn
Dr. Peacock (2001) studied minimum irrigation requirements
for establishing turf from sod, seed, and hydro-seeding
methods during the spring (Figure 1). He found when sod
received 1.3 inches of irrigation and was then not watered
for two weeks, that it maintained acceptable turf quality.
The seeded and hydro-seeded turfs never showed acceptable
quality without irrigation during the same period.
Figure 1. Irrigation requirements for seeded
sodded cool season turf to have same quality.
less chemicals are used with sod, compared to using seed.
Sod is a professionally grown, healthy and mature turf that
is free of weeds and disease-causing pathogens. Less fertilizer
is needed to root sod than is needed when establishing turf
from seed. Properly grown sod has minimal amounts of weeds,
therefore there is no need to apply herbicides. When establishing
turf from seed, weed invasions occur because the soil is not
free of weed seeds. Immature seedlings are also more susceptible
to disease-causing bacteria and fungi than mature plants.
Therefore, you will need to apply chemicals more often on
seeded areas. Sod has less weeds and less disease therefore
requires less chemicals.
Figure 2. Percent weed cover as affected by
irrigation volume at nine weeks after establishment in the
Dr. Peacock (2001) demonstrated that weed pressure during
spring establishment was severe in seeded and hydro-seeded
turfs (figure 2). When 0.9 inches of irrigation was provided,
sodded turf had few weeds, but seeded and hydro-seeded turfs
had more than 30% weed cover. With this much weed cover, herbicides
should be applied to control them.
is certainly more costly than the amount of seed that is needed
for the same area. However, even the best seeding methods
do not guarantee a uniform high quality turf. Higher management
and maintenance costs, compounded by increased water and chemical
applications, as well as delay of use, poor visually unappealing
terrain are trade-offs for the lower initial seed costs. In
the long run, seeded lawn costs are approximately the same
as sod lawns. The costs of overseeding and reseeding washouts,
more chemical applications to control weeds and disease and
higher fertilizer needs all add to this. Seeding of golf courses
delays the opening of the course for play. Golfers will not
pay top dollar for a sparsely covered playing surface, and
they will not accept stones and rocks near the surface that
may damage their golf clubs. With turfgrass sod, you can begin
play on a fairway in a relatively short time, usually, four
to six weeks. Compared to seeding, this could mean hundreds
of rounds of golf earlier, giving owners a quicker cash flow.
Athletic fields can be used up to 11 months earlier when sod
versus seeded fields are compared. Soil erosion cleanup is
generally required with seeded turfgrass areas. Sod has immediate
visual impact, quickly stabilizes soil and is enjoyed up to
11 months earlier than areas prepared by seeding methods.
large grass areas enhances the environment. Grass has long
been part of a healthy environment. Sod reduces runoff and
sediment loss better than any man-made materials, such as
wood excelsior, jute fabric, coconut fiber blanket, etc.
(Krenitsky et al., 1998; Table 2). With today’s ecological
concerns, many more people are considering sod for its environmental
benefits. Turf cools and cleans the atmosphere by reflecting
the sun’s heat and absorbing noises, carbon dioxide
and other harmful pollutants. It releases valuable oxygen
and moisture into the air we breathe. Turfgrass limits wind
and water erosion. Turf acts as a natural filter, reducing
pollution by purifying the water passing through its root
zone. Grass areas provide a safe place for fun and games.
As it grows, grass silently contributes to a healthier
Sod production is viewed by
some people as a form of strip mining and a waste of a natural
resource. An immediate impression is that topsoil is depleted
with each harvest. The facts do not substantiate these concerns.
The lower portion of harvested sod may appear to be soil,
but is really a leafy portion attached to a thatch/
root layer that normally measures ½ to ¾ inches
thick containing a bit of soil. Turfgrass production improves
farmland soil by adding organic materials and nutrients.
Grass roots are continually developing, dying off, decomposing,
and redeveloping. Organic matter keeps soil microbes active
and improves soil chemical and physical properties. Dr.
C. Richard Skogley’s research at the University of
Rhode Island showed that when sod is harvested, most of
the grass root system is left in the soil. He found that
sod fields contained an average difference of 1.9% more
organic matter. Work by Skaradowski and Sullivan found that
sod production fields increased in organic matter with time.
Assuming that a 6-inch depth of soil on an acre weighs 1,000
tons, then this represents 19 tons per acre return to soil.
Based on a five-year study, it could be concluded
that the sod operation had added the equivalent of nearly
four tons of organic matter to the soil each year.
|Krenitsky, E.C., M.J. Carroll, R.L.
Hill, and J.M. Krouse. 1998. Runoff and sediment losses
from natural and man-made erosion control materials.
Crop Science 38:1042-1046.
Peacock, C.H. 2001. Irrigation requirements for turf
establishment under supraoptimal temperature conditions.
International Turfgrass Society Research Journal Volume
Skaradowski, S. and W.M. Sullivan. 1995. The Effects
of Commercial Sod Production on Soil Dynamics. American
Society of Agronomy. Madison, WI. R.I. Agricultural
Experiment Station #3186.
Skogley, C.R. and B.B. Hesseltine. 1978. Soil Loss and
Organic Matter Return in Sod Production. University
of Rhode Island, Kingston, RI FIVE MYTHS OF USING SOD
The New England Sod Producers Association would like
to acknowledge Dr. W. Michael Sullivan & Dr. Zhongchun
Jiang of the University of Rhode Island for researching
organizing the information for this brochure.
| 5 Myths About Sod | Natural
Grass Brochure | Sod Producers
Spec Book |
Copyright © 2005,
New England Sod Producers Association. All rights reserved.