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Archive for May, 2015

Submitted by: Rob Witherspoon, Director, Guelph Turfgrass Institute, robwith@uoguelph.ca

green rolling

Rolling does more than just increase green speed.

A few years ago, I was reviewing the task-scheduling program of a golf course in western Canada and came across a spring task called flintstone greens. Curiosity got the better of me and I contacted course staff to find out just what flintstoning was. It turns out that they had inherited a heavy asphalt roller from a contractor who had done work on their cart paths and found that it was ideal for smoothing out their greens after a hard Alberta winter. (Note: For those of you who didn’t wile away their youth watching Flintstones cartoons, or have wisely avoided seeing the John Goodman movie, here is a video illustrating the source of this reference https://youtu.be/2s13X66BFd8).

The practice of rolling has come and gone and come again in turf management. For many years aggressive rolling of turf areas was generally discouraged other than after seeding to firm up the seedbed or after sodding to improve sod to soil contact. In recent years, rolling has become a much more common practice on turf surfaces and specialized machines and machinery attachments have been designed for green, fairway and sports field rolling. Lawn rolling remains a lucrative spring service in the lawn care industry. Sod growers often roll in advance of harvest to increase the yield and quality of harvested sod. Let’s take a look at some points related to the role of rolling in turf management beyond seeding and sodding.

Smooth out heaving from the freeze/thaw cycle. This is the main reason we see rollers moving around residential neighbourhoods in the spring but it also applies to greens, tees, fairways and sports fields. On low-mown turf soring rolling can reduce mower scalping and improve ball roll early in the season.

Reduce localized dry spot and improve soil moisture retention. Rolling reduces the incidence of localized dry spot, increases soil moisture retention and turf root mass.

Disease Reduction. Dollar spot begins to appear around the same time as lilacs are in early to full bloom and iris are in early bloom. Both research and practical experience have shown that regular rolling results in a reduction in dollar spot severity and an extended period of protection from fungicide applications. Rolling is generally considered a superior method of dew removal and may contribute to reducing other diseases through reduced leaf wetness.

Lower the apparent height of cut without lowering the actual height of cut. On greens and fairways, turf managers claim that rolling allows them to provide faster greens and tighter lies at a higher height of cut than would be possible without rolling. Green speed measurements support this claim. Higher mowing height generally equates with healthier turf. Golf course superintendents may roll as a periodic substitute for a mow or add rolling to increase green speed especially for special events. There is also the practice of target rolling in the vicinity of the hole that increases golfer perception of green speed without rolling the entire putting surface.

Thatch reduction. When combined with sand topdressing, regular rolling is thought to reduce thatch accumulation by the grinding action of the sand particles on the thatch. The improved surface moisture retention may also facilitate the activity of thatch degrading microorganisms.

Smoothing greens and helping core holes close after aerification. Many superintendents routinely roll their greens after aerification to smooth the surface and speed up aeration hole closure. To the casual observer, rolling after aerating would seem counterintuitive as one of the reasons for aerating is to alleviate compaction and regular rolling would likely increase compaction. Recent research by Dr. Thomas Nikolai at Michigan State University indicates that rolling five times per week both improved green speed (2 feet faster after two weeks) and helped the aeration holes close faster. Soil cores taken at the end of the study showed no difference in soil compaction on the rolled versus unrolled plots.

Sustainability. As indicated above, a well-planned rolling program can be part of a money saving, pesticide reducing, sustainable turf management program by allowing higher and less frequent mowing, improving the conditions for growth and reducing disease pressure.

Rolling is not without risks. Avoid rolling during wet conditions especially on fine textured soils. Water acts as a lubricant for soil particles and rolling when the soil is wet can result in serious compaction issues. Routine rolling can also cause wear damage to turf particularly on the edge of greens with tight turning areas. Rolling should be avoided during times when the turf is under stress.

Do you flintstone your turf? What role does rolling play in your management program? Leave a reply/comment and let us know.

Further reading on rolling:

Binder, Nick. 2014. Rolling with the cool kids. Sports Turf Manager. Summer. 27(2): 1, 4-5. 30-37.

Nikolai, Thomas A. 2015. Weighing in on rolling after aerification. Golf Course Management. March. 83(3): p. 82.

Shaffer, Matthew G. 2014. Fairway management at Merion Golf Club. 2014 GCSAA Education Conference: Conference Session Presentations. p. [1-74].

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Its Not Too Late To Get Back to School!!!
Summer 2015 online horticulture, landscape and turf programs begin today and we still have space in a variety of these courses.
Its not too late to join us!!!
• If you register today you will be able to access your course within 24 hours
• Any required course material will be sent to you by courier the same day that you register.
• Your course can be accessed 24 hours a day… seven days a week

You still have time to get organized and participate in the summer 2015 semester. Register until Friday, May 15, 2015.

Visit www.Guelphhort.com for more information and to register now!

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Submitted by: Rob Witherspoon, Director, Guelph Turfgrass Institute, robwith@uoguelph.ca

Turf management has come a long way from the days when a manager would stick a spade in the ground and turn up the sod to examine turf and soil conditions. While fundamental observation skills, experience and intuition are still essential components of the profession, modern day turf managers have a much greater array of tools to monitor turf systems and inform critical management decisions. Let’s take a look at three examples of instruments that may merit a place in your decision-making toolbox.

Measuring Soil Moisture

 Not that many years ago, electronic devices used to measure soil moisture rarely were seen outside of turfgrass research plots. Over the past decade, hand held TDR probes have become almost essential tools for the management of high intensity use turf areas like sports fields and putting greens. They provide soil moisture information that can be used to make irrigation decisions and audit irrigation system performance quickly and accurately. TDR stands for time domain reflectometry and works from the basic premise that the more moisture there is in a soil, the faster an electrical impulse will move through it. When selecting and using a TDR probe to manage soil moisture, it is critical to have probe lengths that measure moisture within the depth of soil containing the majority of turf roots. It is also important to realize that the measurement is only made in the vicinity of the probes – a systematic approach with multiple measurements is needed to gain an overall picture of the moisture conditions on an expanse of turf. Here is a video from TPC Sawgrass Agronomy that describes how they use their TDR probe to manage soil moisture on greens for the PGA Tour’s Players Championship.

 

TDR probe on turg

Fieldscout TDR probe for measuring soil moisture content.

 

Determining Infiltration Rates

 

Double ring infiltrometers are the standard tool used to measure the rate at which water enters (infiltrates) a surface like a putting green or sports field. Knowing the infiltration rate allows you to schedule irrigation more effectively to insure applied water enters the soil and does not run off to adjacent areas. It also helps you assess the impact of various cultural practices like shallow and deep tine aerating, or the application of wetting agents, on the movement of water into turf areas and through the soil profile. Double ring infiltrometers work by having two open ended cylinders that are pressed into the soil. The smaller inner cylinder contains a float with a measuring rod attached. The outer cylinder helps eliminate error from water moving laterally in the soil during the test. Water is added to both cylinders, a float and timer are used to measure the infiltration rate (cm/hour). While a number of double ring infiltrometers are available commercially, if you are handy you could easily rig up a basic infiltrometer using a couple of different sized cans, a ruler and the stopwatch on your smartphone. Here is an example of a basic double ring infiltrometer courtesy of the Food and Agriculture Organization of the United Nations.

 

Measuring Surface Hardness

 

A variety of instruments are available for testing surface hardness of which the most well known is the Clegg Hammer. This instrument measures the deceleration of a free falling weight as it hits a surface that is a measure of the ability of the surface to absorb energy from falls or balls. Surface hardness is particularly important on sports field surfaces. The greater the ability of the surface to absorb shock energy, the less of the shock energy will be absorbed by a falling athlete’s body. Monitoring surface hardness allows turf managers to make decisions regarding practices on natural fields that alleviate hardness, most notably core aeration. The device is also useful for measuring changes in the surface hardness of synthetic fields over time. Surface hardness is also a factor in the playability of many other sports turf surfaces including golf greens, cricket pitches and tennis courts. Here is a link to a short video showing a Clegg Hammer in use.

 

New Turf Tools?

 

The following two devices are examples of the expanding array of high tech instruments that may have a future role in the turf managers toolbox.

The Sphero Turf Research App that claims to be able to use a smartphone controlled ball to simultaneously measure a variety of turf surface characteristics.

 

Aerial drones have been in the news recently for a variety of reasons from package delivery to privacy issues. Drones have also been used to create flyover videos for golf course websites. Greensight Agronomics adds an imager and software processor that provides whole property management insights through daily flyovers of the entire course.

Do you see yourself maneuvering a remote controlled ball around your greens or flying your property with drone-mounted sensors in the future? Do you have a favourite turf tool that has not been mentioned? Let us know in the comments below.

 

 

 

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