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Research Summaries For: The Construction
and Maintenance of Greens
By Dr. Mike Kenna (mkenna@usga.org)
Director, USGA Green Section Research
After years of investigation, the USGA Green Section introduced
its Specifications for a Method of Putting Green Construction in
1960. The method utilized sand as the principal component of the
root zone mix to provide adequate drainage and resistance to compaction,
and incorporated a perched water table in the profile to provide
a reservoir of moisture for use by the turf. When built and maintained
properly, USGA greens have provided good results over a period of
many years for golf courses in most regions of the United States
and the world.
During the past 10 to 15 years, changes have occurred in the way
greens are maintained and in the number of products and technologies
that have been developed. Play has increased, golfers have demanded
closer mowing and perfection in maintenance, new grasses have been
developed that have different maintenance requirements, and many
more golf courses are using recycled water or poor quality water
sources for irrigation. A wide array of organic and inorganic soil
amendments have been introduced, and ideas for new green construction
methods have been proposed. In addition to agronomic changes, the
cost of golf course construction has increased dramatically, threatening
to limit the growth of the game.
To take advantage of new ideas and technologies, and to address
the environmental and economic challenges of the coming decades,
the USGA will sponsor research studies on construction and maintenance
of golf course greens. The goal of this research will be to:
Identify the best combinations of construction, grow in
procedures and post construction maintenance practices that prevent
long-term problems, reduce environmental impacts, and produce high
quality playing surfaces. The reduction of maintenance costs and
resource inputs, and the simplification of construction procedures
were included among the research project objectives addressing this
goal.
During 1995, the USGA Turfgrass and Environmental Research Committee
selected ten putting green construction and maintenance projects
which will be conducted over the next five years at a cost of $870,000.
The Golf Course Superintendents Association of America (GCSAA) will
co-fund five of the projects with the USGA. The following is a brief
summary of the ten projects. Please note that the USGA has directed
over 14 million dollars to support a wide variety of research projects
including the development of new turfgrasses and the impact of golf
courses on the environment. For additional information regarding
the USGA's research activities link to the USGA's Homepage.
Michigan State University
Dr. James Crum
Dr. John Rogers, III
Why are some sands more stable than others? This project
will investigate the physical properties of sands and establish
relationships between strength and stability. The secondary objective
is to evaluate the short and long term effects of post grow-in maintenance
practices on putting greens constructed by three different methods;
USGA recommendations, a modified loamy sand over gravel, and an
unamended loam soil.
Pennsylvania State University
Dr. Charles Mancino
How does the shape (i.e., angular or round) of the sand
effect green performance? The project will first develop a simple,
inexpensive and quantitative procedure to give a reliable estimate
of sand shape without having to examine individual sand grains.
The effect of sand shape on the physical properties of rootzone
sands and whether the particle size distribution needs modification
due to differences in sand shape will then be examined.
Sports Turf Research Institute
Dr. Stephen Baker
Can the conditions for the removal of the intermediate
layer be less stringent? The migration of particles and water retention
will be closely examined where the rootzone layer directly overlies
the gravel drainage layer. Profiles of the rootzone and gravel layer
will be established with different combinations of gravel size,
gravel shape, rootzone mix and initial moisture content. Water retention
in the rootzone layer will be examined when it is placed over intermediate
layers of varying size and composition.
The Ohio State University-OARDC
Dr. Edward McCoy
How does the profile design, root zone composition, slope
of the green, drain spacing, profile depth, and irrigation protocol
impact water movement and the extent of water perching in a USGA
green? This research project will focus on water drainage, redistribution
and use by turfgrass as influenced by a variety of factors related
to modern putting green construction methods.
Rutgers University/Cook College
Dr. James Murphy
How do alternative putting green construction methods
stack up to the USGA Green Section recommendations? Over a five-year
period, recommendations for sand particle size distribution and
the depth of the root zone mix in response to the microenvironment
will be evaluated. A variety of organic composts and inorganic additives
for root zone mixes will be compared to commonly used peat sources.
The physical, chemical, and biological changes that occur as root
zones mature, and the factors which contribute to the success or
failure of greens will be determined.
North Carolina State University
Dr. Danniel Bowman
This research is designed to characterize the physical,
chemical and biological changes that occur in a sand-based golf
course green over the first five years. It proposes a novel two-phase
rootzone mix as an alternative to existing sand:organic matter mixes
and questions whether the incorporation of stabilized organic material
(i.e., sphagnum peat) is warranted over the long term. The research
also will address the question of the perched water table, specifically
regarding changes over time, and possible deleterious effects by
air injection and water evacuation.
University of Nebraska
Dr. Roch Gaussoin
Beyond the questions dealing with the chemical and physical
properties of putting green root zone mixes, how should they be
grown in and made ready for play? Are the high rates of nitrogen
used to accelerate growth a short term solution to meet opening
day, but a path to long term failures? What are the criteria for
allowing play on new greens? This project will evaluate grow-in
and post grow-in cultural practices and procedures and readiness
for play criteria. The long-term effect of these parameters on putting
green performance, depth and extent of turfgrass rooting, and root
zone hydrological, physical and chemical characteristics will be
determined. The project also will assess the influence of these
procedures on the microbes found in the root zone.
University of Georgia
Dr. Robert Carrow
The primary objective of this project is to determine
the effectiveness of selected fall/spring-applied cultivation practices
on the enhancement of bentgrass root development, water infiltration,
and soil oxygen. The effectiveness of selected summer-applied cultivation,
topdressing and wetting agent practices on bentgrass root growth,
water infiltration, and soil oxygen status during the summer months
when root decline occurs will be examined.
Cornell University
Dr. Gary Harmon
Dr. Eric Nelson
This research effort will investigate the nontarget effects
of fungicides used for disease control on golf course putting greens.
The nontarget effects on greens treated with fungicides potentially
include substantial changes in the soil ecosystem which may increase
disease susceptibility and affect nitrogen cycling and the health
of turf.
University of Florida
Dr. Monica Elliott
Auburn University
Dr. Elizabeth Guertal
Clemson University
Dr. Howard Skipper
What species of bacteria are found in new greens? Where
do they come from? How do microbial populations change over time?
This project will monitor the microorganisms in newly constructed
bermudagrass and bentgrass greens on golf courses in South Carolina,
Alabama, and Florida. Effects on bacterial populations will be examined
based on differences among organic material, fumigation, nitrogen
fertility, and clay minerals.
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