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Helping You Have Healthy Turf Issue 1 2003
This
newsletter is the last of our series on understanding the physical test reports
you get from our lab and others. In
this series we have tried to explain some of the testing methods performed and
results obtained. We hope these
newsletters help our clients to become better informed users of our data. Water
release characterization is one of the least known of the physical testing
procedures. It
is used for moisture release and retention evaluation.
Water release testing is a performance evaluation technique that is
valuable in diagnosing turf system problems, guiding turf management practices,
and evaluating the potential usefulness of soils and amendments.
Water
release characterization is somewhat analogous to the USGA performance
evaluation testing suite. However,
the USGA procedure only provides information on the rootzone at a single
tension. The water release test can
provide information on the rootzone at multiple tensions.
Water release characterization
testing is especially useful for determining the water holding and drainage
capabilities for non - USGA type rootzone systems, such as, native materials
construction and straight sand systems. The water release test applies incremental amounts of
pressure to a compacted and saturated core.
This simulates the suction energy (tension) that occurs as a soil dries.
The 0 centimeters (cm) tension is the saturation point and suction energy
levels are near 0 cm. At this
tension, water would move by forces of gravity.
At 30 cm of tension we are at the value of energy used to assess
materials for a USGA perched water green concept with a rootzone depth of 12
inches (30 cm). The water release procedure is capable of producing a
range of soil tensions from the permanent wilt point to field capacity for a
continuous soil profile to saturation. Any
range of soil tensions points between 15 bars (approximately 15,000 cm) and 10
cm can be tested. The data obtained from the testing procedure includes
degree of saturation and volumetric water content (capillary porosity) at the
tested tensions. A series of
moisture release points is then plotted to determine at which pressures a soil
or amendment product releases moisture. Figure 1: Water release curve showing existing soils that are holding excess moisture, and a potential topdress material that releases water more rapidly.
Water release characterization testing results can be
used to evaluate the suitability of a soil or amendment to a particular turf
system. For example, if a designer
wants to determine what depth is optimum for a sports field rootzone; this
testing can help to guide that decision. Likewise,
water release testing can be used to determine proper fairway topdressing
depths, and types of slopes/contouring that is needed.
Water
release testing is also an excellent diagnostic technique.
Undisturbed core samples are evaluated, and the resulting data can be
used to make recommendations concerning turf management, as well as, whether
there is a need for renovation. Laboratory
results can also be directly related to moisture readings taken in the field. A
comparison of water release data to field moisture measurements can provide
useful information for water management practices. Are
you tired of hard to read faxes? Many
of our customers prefer to receive their Turf Diagnostics and Design reports via
the internet. These “electronic
reports” can be printed on your own printer, and they look great.
They even include our letter head and electronic signatures. If you have access to the internet, you can have secure access to your lab data. Give us a call or send us an email, and we’ll set up a web page where you can access your data. SandFinder.com
is the place to find
information on rootzone products. Be sure to check it out at www.SandFinder.com Field hardness or gmax testing by
ASTM F355 is now available from Turf Diagnostics & Design.
If you’re putting in an artificial turf system, contact us about our
quality control programs. As
most of the readers of this newsletter already know, Turf Diagnostics and Design
(TD&D) is a physical evaluation laboratory and agronomic consulting company.
Our laboratory is accredited by the American Association for Laboratory
Accreditation in the area of geotechnical testing. There has been
considerable concern in the construction industry about the infiltration rate
test (KSAT). While we appreciate
these concerns, we feel you should know that our tests are performed with a high
amount of attention to detail and extensive quality control checks.
We believe that our KSAT testing provides accurate, reproducible testing
results that are a useful tool for evaluating rootzone amendments.
We also want to let you know that we are constantly evaluating, updating,
and improving our testing procedures. All labs are
not the same. For fast, reliable
data and dependable lab consultations, you need Turf Diagnostics & Design! To enlist our cost effective services, or for more information, contact Sam or Duane at: Turf Diagnostics and Design, Inc.
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