This week I spoke to a full room of turfgrass managers at Bangkok's Thana City Golf and Sport Club about an important topic: understanding data for use in turfgrass management. I've recorded this video of the presentation slides in which I discuss the two classes of data that can be collected – data about playing surface performance, or data about plant growth – and then I go into some detail about soil moisture and photosynthetically active radiation (PAR), with a brief mention of salinity and soil pH at the end.
There were many questions and an active discussion in this seminar and in fact lunch time arrived before I could speak about salinity and soil pH, so this video provides the narration of what I would have talked about had there been more time.
David Lau from Spectrum Technologies, pictured with me at right, gave an interesting presentation in which he talked about a broad range of meters and software that can be used to collect and analyze information for improving turfgrass performance. This is part of what PACE Turf call Precision Turfgrass Management (PTM), which is a systematic effort to provide optimum turf performance using minimum resources. As David mentioned, we cannot manage something if we do not measure it.
Today was an especially hot day at Bangkok. I went out for lunch, and when I was driving home I noticed that the thermometer on my dashboard was indicating an outside temperature of 42°C. Upon arriving home, I checked the official temperature, found it to be 38°C, and I promptly went outside with my infrared thermometer to measure the surface temperature of concrete and of grass. See the above image at full size here.
These measurements were made at 14:00. The concrete measured 53.6°C, about 15°C above the air temperature. Manilagrass (Zoysia matrella) wilting in the sun had a similar temperature, 48.8°C, more than 10°C above the air temperature. Meanwhile, manilagrass and carpetgrass (Axonopus compressus) in the same lawn, in areas with adequate water so the grass could transpire, had leaf temperatures ranging from 1.8°C below to 1.2°C above the ambient air temperature.
As part of a putting green performance data research project, I've collected leaf temperature data from hundreds of greens across multiple grass species in many countries. As of today, I've measured the surface temperature 802 times. If you are interested in reading more, these data are summarized beginning on page 21 of this report. It has been my observation that in conditions of full sun, minimal wind, and adequate plant water status, meaning the grass leaves are not wilting, no matter how hight the ambient air temperature, the leaf temperature will generally be within 1°C or 2°C of the air temperature. Have you ever measured anything different?
It is a well-known phenomenon that application of nitrogen favors grasses and reduces species diversity (i.e. reduces the number of weedy species), while increasing the soil pH through addition of lime, and adding potassium fertilizers, as an example, can increase the prevalence of weeds. In a brief exchange on twitter last week, we discussed this, and decided to make this subject the focus of the upcoming Turf Chat.
Dr. McElroy says that this phenomenon is already known, while I would argue that despite it being noticed more than 150 years ago, and the mechanisms of this worked out more recently, among turfgrass managers, there is not universal knowledge of these principles.
Have a look at this image. It is an aerial view of Wack Wack Golf and Country Club, a 36 hole golf course in Manila. The West Course is on the left side of the image, and the East Course is on the right side. Do you notice a difference in the grasses?
To me, the grass on the East Course looks greener and healthier than the grass on the West Course. And the grasses are different. The East Course has broadleaf carpetgrass (Axonopus compressus) fairways and manilagrass (Zoysia matrella) greens; the West Course is all hybrid bermudagrass.
Trees on the East Course (see below) throw shade everywhere, but the carpetgrass and manilagrass still thrive in these conditions. The bermudagrass does not.
Just down the road at Manila Golf Club, there is some incredible shade thrown across the course each morning by a row of 55 story buildings on the east side of the property.
In such heavily shaded conditions, manilagrass performs the best, then seashore paspalum, with bermudagrass (Cynodon) not doing well at all. In the photo below, I identify the manilagrass with my nose, and the bermudagrass test plots identify themselves - they are basically dead.
In tree shade or in building shade in Southeast Asia, manilagrass performs exceptionally well as a fine turfgrass. But there is another type of shade, one that can block up to 75% of photosynthetically active radiation. That is the shade that comes from clouds.
Last week, I took this photo at 10:51 in the morning. The sun was behind a cloud and the quantum meter has a reading of 498 micromoles of photosynthetically active light per square meter per second. That is less than 25% of full sunlight. The effect of clouds is not terribly important for cool-season grasses, and most textbooks ignore it, but this is a big issue for warm-season grasses.
I've studied and written about this and its relevance particularly to the conditions so common in East and Southeast Asia.
From Indonesia in the south to Japan in the north, we see that manilagrass, and in the areas with average annual temperature above 22°C, carpetgrass as well, perform extremely well. Particularly in shaded conditions, which can be caused by trees, buildings, or clouds, these grasses outperform bermudagrass and seashore paspalum.
In the My View section I've written about grass selection for greens and fairways in Asia. My view is that when it comes to putting greens, because they occupy such a small area of the course and no matter which grass is chosen the greens will always receive intensive maintenance, a high maintenance grass is often the right choice. And my view for fairway turf, because fairways occupy such a large area of the course, is that it is best to choose a grass that won't die. When the grass won't die, then turfgrass managers are able to modify the playing conditions to create almost any type of surface. In Southeast Asia, these grasses that don't die are manilagrass (Zoysia matrella) and broadleaf carpetgrass (Axonopus compressus).
To those eleven species, I can add Stenotaphrum secundatum (above), which we saw thriving as a lawn grass in some parts of Catalonia, and also Zoysia matrella, which we saw on a few traffic circles.
At the Semillas Fitó turfgrass experimental station we saw seeded kikuyugrass and seeded Cynodon dactylon along with a variety of cool-season turfgrass varieties. I was especially interested in the Playa seed mixture which looked great on the research plots and contains seed from four different species: Cynodon dactylon, Festuca arundinacea, Poa pratensis, and Lolium perenne.
And at Golf Platja de Pals, the first course on the Costa Brava, designed by Fred Hawtree, and site of the 1972 Spanish Open, the turf is almost all Poa annua, and one can even find pink snow mold (Michrodochium nivale) in the shaded areas there.
I think it is pretty amazing to see thirteen turfgrass species, all performing pretty well, and even in early December to see green Stenotaphrum secundatum and green Zoysia matrella and green Cynodon dactylon alongside Poa trivialis and Poa annua. If I had a lawn in Catalonia, I think I would plant the Playa mixture from Semillas Fitó myself, just for the novelty of having a mixture of warm- and cool-season grasses in the same lawn, and because the other types of Festuca arundinacea that I saw were performing very well.
In Southeast Asia, there are just a few species of grass that work well as a lawn or as a sports turf. In northern Europe, there are just a few species that work. At Catalonia, I saw thirteen species, all growing, to some extent, very well. In Sydney, or in Brisbane, or in San Diego, or in Atlanta, we can have a wide range of species, but I don't think I've ever been anywhere where such a wide range of grasses were growing.
I visited Gran Canaria and its seven golf courses this week, choosing this island in particular because of its many microclimates and consequently the chance to study a variety of grasses in different environmental conditions.
Location (in blue) of the 7 golf facilities on Gran Canaria
I also have friends (*see below) on this island, which made it an even more appealing place to visit. The north side of the island sees more clouds, and the south side of the island has more sunshine, and in general, it is a rather dry island. At the airport, near Telde in the East, the average annual rainfall is 134 mm. Contrast this with Bangkok, where grasses, many of them the same as at Gran Canaria, grow in a climate with almost 1,500 mm average annual rainfall. In fact, at Bangkok, there are six months of the year, each of the months from May through October, that have average rainfall more than the 134 mm annual average at Telde.
That lack of rainfall makes irrigation crucial to the performance of any turfgrass as a sporting surface at Gran Canaria, and because almost all of the courses are irrigated with treated wastewater, which is rather high in salinity, careful attention to water quality is just as important as water quantity, as is choosing the grass species that can tolerate such salinity.
At the seven golf clubs on the island, there are nine courses. Salobre is 36 holes, and Anfi Tauro has a short course. The grass breakdown is this. On greens, four courses are creeping bentgrass, four are seashore paspalum, and one is bermuda. Through the green, one course is kikuyugrass, four are bermuda, and four are seashore paspalum.
There is some Poa annua growing, mixed in with bentgrass on some greens, and as a weed in some fairways. I also saw some perennial ryegrass, although it was not thriving. And there was Stenotaphrum secundatum (St. Augustingrass in the USA, buffalograss in Australia) growing well in a few parks, but I did not see it on any golf courses.
At Real Club de Golf de Las Palmas, some unirrigated picon areas between tees and fairways have drought-tolerant bermudagrass growing in these dry conditions. The tees and fairways, which receive irrigation, are covered with kikuyugrass. A collection of photos are posted at Flickr (and below) where you can see the grasses and the golf courses of this diverse island.
*Alejandro Rodriguez Nagy, who arranged the schedule this week and introduced me to the greenkeepers at each course; Daniel Carretero, who played on the golf team at the University of Portland (my hometown) and worked at Augusta National GC where I met him during the 2011 Masters Tournament; and Oscar Sanchez, who I caddied for at Waverley CC when he played in the 1993 USGA Junior Amateur Championship.
I used to call myself the Research Director of the Asian Turfgrass Center. Then I decided that Chief Scientist would be a fun (or a more rakish?) job title, and I am glad that I did, because Científico Jefe has a nice ring to it. At the invitation of La Asociación Española de Greenkeepers, I'll be speaking at the 34 Congreso Anual de Greenkeepers (Spanish Greenkeepers Congress) in Madrid at the end of this month on the topic of Nutrición y Requerimientos reales para greenes en España (Nutrient Requirements for Putting Greens in Spain).
I'm also giving a seminar for the Thai GCSA on 13 November. The topic on that day is putting green performance and will go into some detail about soil moisture, surface hardness, and how the organic matter in sand rootzones can be managed to optimize surface conditions. That seminar will be translated into Thai.
In February, I'll be giving seminars at Tokyo and Japan about ultradwarf bermudagrass management and in India about techniques that can be used to improve course conditions. Then in March at Thailand I will be teaching about turfgrass nutrient requirements, and I'll also be providing an online seminar (webcast) about seashore paspalum for GCSAA.
That is a lot to prepare for, on various topics, and we will see materials translated into Spanish, Japanese, and Thai. I'll share these slides and handouts as much as possible once they are available.
For a list of upcoming seminars and conferences that may be of interest to those who work in the turf industry in Asia, see the ATC Calendar. I keep that calendar updated with relevant industry and educational events and although I'm not speaking at all of these events, I will be at some of them.
A few days ago I read a post on the Golfdom Daily about soil pH in which it was suggested that it was important to maintain soil pH in the range from 6.5 to 7.0. The reason was given "that most nutrients (whether applied or in the soil) are readily available to the plant in this pH range. Outside of this range many nutrients (both macro- and micro-nutrients) are not readily available to the plant."
That dogmatic statement about pH is not correct. The truth is that most turfgrass species grow well, with ample nutrient availability, in a pH range from 5.5 to 8.3. In some cases we can have excellent turf even with soil pH less than 5.5. In fact, at the Asian Turfgrass Center's research facility in Thailand, many grasses were maintained as a fine turf in soil with a pH of 3.7. Compared with the same variety grown at pH 7, we could find no visual difference.
So what is the real story about soil pH? The superb article Farming with Acidity by Sumner and Yamada explains just what the issues are. They start by explaining that the supposed optimum range for soil pH is an artifact of the soils and cropping systems used when the pH meter was first introduced:
In many parts of the world notably the US Midwest and Europe, soils have been limed to a particular target pH (6.5–7.0) according to the crop. Because plants do not directly respond to the activity of H+, it is pertinent to enquire why this approach to liming has enjoyed such widespread popularity. Among the reasons, the original near-neutral pH of many of the soils was no doubt a consideration and the use of acid-sensitive legumes to supply N in rotations in the early stages of agricultural development also played a part. The introduction of the pH meter at about the same time as N fertilizers found widespread popularity replacing legumes in rotations facilitated the measurement of soil acidity and removed the focus from the real problems of soil acidity, namely, toxic levels of Al3+ and Mn2+ and deficiencies of nutrients such as Ca, Mg, N, S, P and Mo. Even after legumes disappeared from the rotations, the high target pH values were retained. (Sumner and Yamada, Communications in Soil Science and Plant Analysis, 2002)
The article reviews scores of experiments and concludes that:
There seems to be little merit in liming soils to pH values greater than 5.5 at which exchangeable Al is effectively neutralized. Additional benefits accruing to this strategy are: (a) reduced costs of lime, (b) reduced nitrification and attendant pollution of surface and ground waters, (c) control of diseases and pests, (d) improved infiltration and water use efficiency, and (e) increased nutrient availability. (Sumner and Yamada, Communications in Soil Science and Plant Analysis, 2002)
For some distinctly non-dogmatic information about fertilizer, pH, and turfgrass nutrient requirements, see:
This short video will be of interest to golf course architects, superintendents, and anyone involved in the management or development of golf courses in tropical and sub-tropical Asia. Cut to just eight minutes in duration, it is a narrated walk along 5 km of Ishigaki island coastline, describing the grasses encountered and showing the ecological setting in which these grasses grow naturally.
