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January 2011

December 2010

Plant Available Nutrients in Sand Rootzones

Golf course putting greens and other high-use turf are generally grown in a sand rootzone. In Asia, many courses also have tees, fairways, and sometimes even rough areas plated with sand as well. This poster, which I prepared for the Oregon State University turfgrass field day in 2005, shows some interesting results on the measurement of plant-available nutrients in sand rootzones. In this poster I showed data looking specifically at calcium, magnesium, potassium, and sodium. Download the poster in PDF format by clicking here (1.6 MB).


The soil nutrient analysis (soil testing) procedures used at commercial laboratories were developed for soils that contain clay and silt particles. The sands used on golf courses and other fine turf areas are expressly selected to be relatively free of clay and silt. The data in this poster show that conventional soil test extractants such as Mehlich 3, normal ammonium acetate, and sodium acetate (Morgan extractant) overestimate the available nutrients in sand rootzones.

For the purpose of making fertilizer recommendations, it doesn't really matter whether the extracted nutrients are plant available or not, as long as the fertilizer recommendations are accurate. But for estimating cation exchange capacity (CEC), it is clear that conventional soil tests overestimate the CEC of sand rootzones. Sand has an effective CEC of zero. Therefore, we can use an empirical relationship based on the contribution of soil organic matter to CEC. For a quick and accurate estimate of the CEC of a sand rootzone, use this equation:

CEC = (-311 + (268 × pH)) × (OM ÷ 1000)


CEC units will be cmolc kg-1 which is equivalent to meq/100 g

pH is the sample pH

OM is the organic matter percentage of the sample, in %

In tests conducted at Cornell University on sands collected from golf course putting greens around the world, we found that the simple equation above is a more accurate predictor of the sample CEC than are conventional soil tests. So if you really want to know how many nonacid cations (calcium, magnesium, potassium, and sodium) can be held in a sand rootzone, use that equation. All you need to know is the soil pH and organic matter content.

Turfgrass Science Seminars at Tokyo and Osaka

On 14 and 15 December I gave seminars at Tokyo and Osaka, respectively, to audiences of greenkeepers who came for a full-day seminar about turfgrass science. It wasn't just greenkeepers from those cities, in attendance, however; some greenkeepers traveled all the way from Niigata, Mie, and Yamaguchi to spend a day learning about new developments in turfgrass science that can be applied in their day-to-day work.

Woods_ueno The translator for these seminars was Mr. Yukio Ueno who also translates the monthly article I write for ゴルフ場セミナー magazine. The cost of putting on these seminars is offset by generous support from Syngenta, Toro, and Simplot. The fourteen page seminar workbook for the December seminars can be downloaded here.

Additional seminars in this series will be held at Tokyo on 19 January and 22 February, and in Osaka on 20 January and 24 February. Register for those seminars by clicking here.

Seminar_osaka The January seminars will discuss turfgrass growth potential, fertilization, turfgrass stress, management of soil water, and a number of other topics that will be of interest and practical use to turfgrass managers in Japan.


Chiba University Seminars

I gave two lectures at Chiba University this week, one on Ten Things Every Horticulturist Should Know About Turfgrass, and another on Turfgrass Selection and Management in Asia. These lectures were for Masters and Doctoral students in the graduate school of Horticulture.

Shinkansen_fuji_view It is a great time of year to be at Japan, and it is always fun to speak with students about turfgrass. Chiba University has an innovative expert program within the Graduate School of Horticulture and attracts students from Japan, Europe, Africa, and many countries in Asia. The students in my lectures were from Vietnam, Uganda, India, Cambodia, Thailand, Japan, Germany, China —that is what I recall!

Most of my seminars are for professional turfgrass managers, but it is fun to speak with students at the university. In 2009 I spoke at seminars at University of the Philippines Los Baños and at National University of Singapore. Next March I have a seminar at University of Tennessee, and hopefully there will continue to be opportunities to speak with students at universities in Asia. As I mentioned to the students at Chiba University last week, Asia is a particularly difficult part of the world to grow grass, because of the climate, and the thousands of jobs in the turfgrass industry across Asia require people with a good technical understanding of turfgrasses and their management.

Registration Open for March 2011 Turfgrass Conference

Registration is now open for the Sustainable Turfgrass Management in Asia 2011 conference, to be held at Pattaya, Thailand, on 14 to 16 March. Registration forms, speaker profiles, and the program schedule are all posted at the conference website,

Seminar_room The 2011 event includes sessions with renowned turfgrass expert Dr. Don Loch from Australia, Dr. Jim Brosnan who heads the turfgrass weed science program at the University of Tennessee, and a new session with talks on successful techniques used by golf course superintendens at Thailand. Philip Russell from The R&A will open the conference with a talk on Understanding Sustainable Management with a special emphasis on the economic benefits that accrue from such an approach.

Field day The conference has been approved by GCSAA for 1.0 education points. And the classroom seminars are combined with the 5th Asian Turfgrass Field Day, this year looking especially at weed control in all types of grass, different species of zoysiagrass and their management requirements, along with other field demonstrations at golf courses near Pattaya.

Conference_dinner The conference venue is the Amari Orchid Pattaya, a 5-star beachfront hotel with a superb dedicated conference facility, as the hundreds of delegates from the 2009 and 2010 conferences can attest.

Organized for the Thailand Golf Association by Asian Turfgrass Center and the Thailand GCSA with support from The R&A, this event provides a wealth of practical information in a fun learning environment.