Viridescent - the Asian Turfgrass Center blog

Sunshine, Zoysia, and Grass Performance in Asia

There are four grasses in the image above (click on it to get a larger view). We are looking at Tifeagle and Novotek (both are Cynodon hybrids), Sea Isle Supreme (Paspalum vaginatum), and a fine-bladed zoysia, probably Zoysia pacifica. This is a test on a shaded green in Manila. The green is maintained for seashore paspalum. The seashore paspalum can handle this shade, although it has a relatively coarse leaf blade compared to the zoysia. Both types of Cynodon fail to produce an acceptable putting surface in this type of shaded condition under which both seashore paspalum and zoysia can produce a good stand of turf.

In fact, this zoysia produces a really superb putting surface, as seen at right, a photo I took on the 18^th green at Wack Wack Golf and Country Club during last week's Philippine Open. It requires very little in the way of fertilizer, few pesticides, and is able to tolerate the low sunshine levels and tree or building shade that can cause Cynodon, with its higher light requirement, to fail. Wack Wack recently underwent a renovation and the Club made a wise choice to keep the native zoysia on greens and the native carpetgrass everywhere else. There are beautiful mature trees across the property, and other grasses would not produce such fine surfaces in these low light conditions, but the zoysia and Axonopus thrive.

Many people ask me "what type of zoysia is that?" My best answer is that it is probably a type of Zoysia pacifica (previously called Zoysia tenuifolia), and I base that on a paper published in 2005 by Akamine et al. in volume 33 of the Journal of the Japanese Society of Turfgrass Science entitled "Morphological Characteristics of Zoysia tenuifolia Willd." In the research project reported in that paper, Akamine et al. found that Z. pacifica leaves are folded in the sheath, as compared to Z. matrella leaves which are rolled in the sheath. Upon close inspection, I found that the fine-bladed zoysia from the greens at Wack Wack has folded leaves, while the leaves of a typical Zoysia matrella from Japan were rolled.

For more information about sunshine, shade, turfgrass performance in Asia, and links to a lot more information about assessing the sunshine hours close to your location, here is a video I've recorded with Dr. Larry Stowell from PACE Turf about light.

Calcium for Turfgrass: is there enough in the soil?

The answer, almost certainly, is yes. These calculations of how much calcium the grass uses, compared to how much plant-available calcium is in the soil, leave little doubt that there is almost always more than enough calcium in the soil to meet the needs of the grass.

How much calcium does grass use?

Let's take a turfgrass site at which clippings are removed, and estimate how much calcium is removed, or harvested, in one year. A reasonable estimate for annual clipping yield of maintained turfgrass is about 400 g m^-2. A reasonable estimate for calcium in the dry matter of turfgrass clippings is about 4500 ppm = 4.5 g kg^-1 = 0.45%. So if we harvest, over the course of a year, 400 grams of clippings from each square meter, and if those clippings contain on average 0.45% calcium, then the mass of calcium harvested from one square meter each year is:

400 g x 0.0045 = 1.8 grams of calcium removed each year

How much calcium is in the soil?

We've just calculated that in the situation where we remove the clippings from a maintained turfgrass area, we may be removing about 1.8 grams of calcium from each square meter each year. Let's now imagine that our root system is 10 cm deep, and that the bulk density of the soil is 1.5 g cm^-3. In one square meter, then, to a depth of 10 cm, we have a volume of 100 L, and a mass of 150 kg. Let's say this is a sandy soil, with a relatively low cation exchange capacity, and that the plant-available calcium (the calcium that is in soil solution and on cation exchange sites) is at a concentration of 400 ppm = 400 mg kg^-1. How much calcium is that?

150 kg of soil x 400 mg/kg = 60,000 mg of calcium = 60 g of calcium

Three Decades

That's how long it would take, 33.3 years, to be precise, for the grass to use 60 grams of calcium if harvested at the rate of 1.8 grams of calcium per year. There is much more calcium in the soil than is required for healthy turfgrass, even in soils that have relatively low amounts of calcium.

World Cities Plotted by Climatological Normals, February

February is another good month, on average, to grow grass in Bangkok, Chennai, Colombo, and Mumbai. Why? With average temperatures more than 25°C and sunshine well above 200 hours for the month, the growth of warm-season grasses can easily be controlled by turfgrass managers through adjustments in the amount of water and nitrogen applied. 

Hainan Island is sometimes referred to as the "Hawaii" of China, but Sanya is considerably cooler and has a lot less sunshine than does Honolulu in February. For about six months of the year, Sanya is a lot more like Hilo than Honolulu, and that means slightly cooler temperatures and significantly less sunshine. 

Research, Teaching, and Speaking in Tennessee

I visited Tennessee this month, speaking at the packed Tennessee Turfgrass Association conference, meeting with faculty in the Plant Sciences Department at the University of Tennessee (of which I am an adjunct faculty member), learning about some of the turfgrass research projects now underway at the University, and teaching this semester's first session of the Turfgrass Rootzone Construction and Management course.

I participated in a panel discussion with Rodney Lingle (Memphis CC), Matt Shaffer (Merion Golf Club), and Chris Hartwiger (USGA Green Section) in which we discussed ultradwarf bermudagrass management, preparation for the 2013 US Open, cold tolerance of bermudagrass, and heat tolerance of creeping bentgrass. I gave three other presentations at the conference, on topics ranging from course preparations for the Open Championship, fertilizer for sand rootzones, and turfgrass management in Asia. The attendance at the conference was superb. In fact, for many of the presentations it was standing room only, and the trade show was bigger than I had expected too.

At the University of Tennessee I saw the now completed Center for Athletic Field Safety with some really great looking synthetic surfaces along with natural turf. This impressive facility is being used for some cutting-edge research about sporting surfaces, biomechanics, and athlete safety.

I saw a lot of other research as well -- zoysia trials, lots of weed control work, many with the new herbicide indaziflam, rooting experiments, seedhead control of zoysia -- suffice it to say that there is a lot of interesting information being developed by the turfgrass team at the University of Tennessee.

We also discussed turfgrass educational programs in Asia and weed control in India for upcoming sessions of the Indian Golf Union's Greenkeeper Education Programme.

At the end of my week in Tennessee, I taught the Plant Science 442 course, Turfgrass Rootzone Construction and Management. I talked about sand rootzones, why we do core aerification (coring, hollow-tine aerification), and what some of the challenges are in managing turf in sand rootzones. I spoke, basically, about these topics:

• Managing the rootzone (handout from Sustainable Turfgrass Management in Asia 2010)
• Managing the rootzone (presentation slides from Sustainable Turfgrass Management in Asia 2010)
• Do fairways need a sandcap? (article from Asian Golf Business)

Chemical Fertilizer Programs for Sand Based Rootzones - the 1 minute version

Last week at the Tennessee Turfgrass Association conference I gave a 30 minute presentation with the title Chemical Fertilizer Programs for Sand Based Rootzones. But this topic doesn't always require 30 minutes to explain - I like to distill this topic into the most important principles. There is plenty of experimental and empirical evidence to show that these four principles, if followed, will give excellent results.

1. Apply the right amount of nitrogen
2. Ensure soil pH is more than 5.5 and less than 8.3
3. Ensure soil potassium (as measured by the Mehlich 3 extractant) is kept above 50 ppm
4. Ensure soil phosphorus (as measured by the Mehlich 3 extractant) is kept above 35 ppm

The End (of the 1 minute version of this topic)

If you are especially interested in mineral nutrition for turfgrass or soil nutrient analysis for sand rootzones, you may want to read or watch some of these more lengthy expositions.

Simple Fertilization: Use the Nutrients Already in the Soil, from the Hawaii GCSA newsletter

PACE Turf Potassium Sufficiency Video, on Youtube

Soil Testing: It Does Not Have to be Difficult, on Youtube

Creating an Excellent Playing Surface: Managing the Plant, especially section 2 regarding nitrogen application

Does Potassium Fertilizer Really Increase Roots?, from TurfNet Monthly

And for those who really want to reduce P and K, consider the implications of The Park Grass Experiment and the Fight Against Dogma, written with Dr. Frank Rossi and published in the USGA Green Section Record

Potassium for Turfgrass: interview with Dr. Larry Stowell of PACE Turf

Dr. Larry Stowell and I recorded this video interview about potassium fertilizer for turfgrass. How much potassium is enough? How should you decide how much potassium to apply to meet the plant requirements, without wasting money by applying too much? Is potassium fertilizer necessary at all? Watch this video to find out, and check out PACE Turf for a wealth of valuable turfgrass information.

Cynodon, Paspalum, and Zoysia at Putting Green Height

Golf course putting greens in Southeast Asia are usually planted to either hybrid bermudagrass (Cynodon dactylon x C. transvaalensis), seashore paspalum (Paspalum vaginatum), or zoysia (Z. matrella or Z. pacifica). I saw this test recently at a golf course in Southeast Asia. This is a putting green in an area with extensive cloud cover for much of the year. Can you identify the species being grown here? Which are bermuda, which are paspalum, and which are zoysia?

This green is being maintained at about 4 mm, the test plots have been established for more than three months, and there are obviously some differences in how the grasses perform at this mowing height. This test corresponds exactly with what I have observed on the performance of these grass species at low mowing heights across a broad swath of Asia.

World Cities Plotted by Climatological Normals, January

This chart shows a selction of world cities, plotted by average temperature, sunshine, and precipitation for the month of January. Bangkok, Chennai, Colombo, and Mumbai look like splendid places this month, at least for the growth of warm-season grasses. It will normally be warm, sunny, and dry in these cities, allowing turfgrass managers to control the growth with fertilizer and water applications, without concern for a lack of sunshine. 

World Cities Plotted by Annual Climatological Normals

On these charts, a selection of world cities are plotted according to their average annual temperature and average annual sunshine hours, with the size of the bubble for each city proportional to the average annual precipitation. The display of information in this way allows us to identify quickly some differences between the normal climate in different locations. Miami and Honololu, for instance, are very similar in average annual temperature, and almost the same in sunshine, but Miami has much more rainfall than Honolulu. 

The charts are shown with the x and y axes going to zero in the plot above, to get some sense of the range of variation in the data, and in the chart below the data are plotted to fit the chart, so that we can more easily identify the location of the cities. Atlanta has a similar annual temperature to Osaka, and similar precipitation, but there are about 40% more sunshine hours in Atlanta each year than in Osaka. That difference is clearly something to consider if we think about how, for example, ultradwarf bermudagrass greens would perform, or should be managed, in those different locations. 

Photosynthesis is affected by temperature, light, water availability, and leaf nitrogen content. Turfgrass managers control the nitrogen by judicious application of fertilizer, and the water availability is controlled partly through precipitation and partly through supplemental irrigation. Light and temperature, then, stand out as the uncontrollable influences on photosynthesis. In the warm-season areas of the United States, there tends to be relatively high sunshine. It is normal to have 2500, 3000, or even 3500 sunshine hours in a year. So in the United States, much of the grass selection, when it comes to warm-season (C₄) grasses, is just a matter of temperature -- "is this a warm-season area, by temperature, or not?" 

In Asia, there tends to be less sunshine. If we compare Hong Kong with Miami, we see that Miami is slightly warmer, and Hong Kong has a bit more precipitation, but there is a huge difference in sunshine hours, with Miami having on average about 70% more sunshine hours than at Hong Kong. Does this have an affect on turfgrass performance? Yes! We see Zoysia matrella thriving in Hong Kong, and Singapore, and Tokyo, all cities where the sunshine hours are relatively low. Bermudagrass, on the other hand, performs relatively poorly in these same cities, and requires special care to keep in a playable condition. 

ATC in 2011, by the Numbers

As we come to the end of another year, it is interesting to look at some of the numbers related to the work done this year, particularly in comparison with the previous years (2009 report, 2010 report). In 2011, I'm especially glad to see that we continue to provide more people with turfgrass information through our websites and training programs.

• Visitors from 119 countries visited this website, Viridescent, for which I wrote 60 new posts in 2011. Both are a substantial increase over 2010, and we saw a 22% increase this year in unique visitors to the Asian Turfgrass Center, Asian Turf Seminar, and Viridescent websites.
• Volume of soil and water analyses for select clients in Asia were up by 70% this year as turfgrass managers see the value in a scientific approach to plant nutrition.

• I made about 35 presentations at universities, educational conferences, and golf course superintendent meetings at Japan, Australia, China, Thailand, India, United States, and the Philippines. The highlights include keynote talks about plant nutrition at the Australian Turfgrass Conference in Adelaide in June and conducting the India Greenkeeper Education Programme at Kolkata, New Delhi, Mumbai, and Bangalore in November and December.
• My work took me to fifteen countries in 2011.
• I flew 94 times, an average of one flight every 3.9 days.
• Fourteen articles were published in 2011 including the cover story from the January Greenkeeper International and the story I wrote with Dr. Frank Rossi about the endlessly fascinating Park Grass experiment, published in April by the USGA Green Section Record.
• I made ten posts at the Turf Diseases website - newly redesigned this year - for which I am an occasional contributor on international topics.
• Visitors to the Asian Turfgrass Center website were from 70 countries and the top ten countries sending visits were, in this order: Japan, United States, Thailand, Australia, Malaysia, India, United Kingdom, Singapore, Philippines, and China.
• I made nine interactive bubble charts of climatological data and fourteen static charts; these data graphics are useful in predicting which grasses will perform well in specific geographic regions and in preparing maintenance calendars for different grass types.
• Data were collected from 220 putting greens in six countries growing seven species of grass. This ongoing project characterizes the playing performance of different grass species and establishes normal values for different grass species in Asia. 
• This year ends, as did 2010, with plans for a number of upcoming seminars, advisory work for great clients, travel to salubrious places, and a long list of exciting writing projects.