Japan

99 article titles

GcSeminarCovers

I've been writing a monthly article for ゴルフ場セミナー (Golf Course Seminar) magazine since May 2008. That's 99 articles so far, and 118,518 words. The best of these will be published in English, sometime; for now they are only available in Japanese. The first 36 of these articles are available in PDF format here.

Starting in May 2008 (#1) and going up to July 2016 (#99), these are the article titles in English.

1. What is Greenkeeping? The 6 Basic Principles
2. Soil Water: How to Manage it in the Summer
3. Fertilizer for Grass: Soil, Leaves, and Growth Potential
4. 5 Maintenance Activities That May Increase Roots
5. Coring: Do it Right, and Get Better Greens
6. Simple is Better: An Amazing Experiment at Rothamsted
7. Sand Topdressing by Numbers
8. 2008 International Turfgrass Science Quiz
9. Why is Grass Green?
10. 2008 International Turfgrass Science Quiz - Answers & Discussion
11. Golf Course Maintenance Expenditures in 2009
12. Putting It All Together: summarizing the six points of greenkeeping
13. The most important thing to know about creeping bentgrass
14. The 2009 US Open, Bethpage Black, and Integrated Pest Management
15. Effective spraying: nozzles, water volume, and droplet size
16. The Critical Component of Putting Green Management
17. The Critical Moisture Content of Soils
18. Some New Turfgrass Research Results
19. The Optimum Level of Plant Nutrients in the Soil
20. A Christmas Gift List for the Turfgrass Scientist
21. Two Equations for the New Year
22. Old and New, from Scotland to China
23. Roll Three Times a Week for Better Greens
24. Turfgrass Maintenance by the Numbers
25. Current Trends in GC Maintenance
26. Thatch: Definition & Management
27. Does Phosphorus Cause Algae on Putting Greens?
28. Pebble Beach Putting Greens: Playing Condition vs. Appearance
29. One Good Thing About the Summer
30. The Foundation for a System of Golf Course Maintenance
31. Practical Application of Turfgrass Science Principles
32. Labor Analysis and Priority of Maintenance Work
33. A Scientific Guide to Turfgrass Maintenance this Year: Part 1
34. A Scientific Guide to Turfgrass Maintenance this Year: Part 2
35. A Scientific Guide to Turfgrass Maintenance this Year: Part 3
36. Data + Science + Technique = Better Grass Conditions
37. How Poor Greens Became Excellent Greens at Vietnam: a case study
38. Tublamu Navy Golf Course & the 2004 Indian Ocean Tsunami
39. Thai Country Club: Great greens with terrible water
40. An Almost Insurmountable Problem: nematodes
41. What’s in the irrigation water at the Home of Golf?
42. Converting to Ultradwarf Bermudagrass: why and how
43. Choosing Soil Moisture Meters
44. Using Soil Moisture Meters
45. Firm Putting Greens at Australia
46. Fertilizing Greens in the West Coast Style
47. Using Soil Test Data to Improve Turfgrass Conditions
48. A Common Cause for Putting Green Problems
49. Rolling Greens: What do the Data Show?
50. Green Speed and the Brede Equation
51. Cooling the Soil
52. Soil Moisture Content of Putting Greens in Japan
53. The Clegg Hammer and the “Hardness” of Putting Greens
54. Cooling the Soil at Night
55. Measuring Photosynthetically Active Radiation
56. Green Speed Variability
57. Green Hardness: Yamanaka Tester vs. Clegg Hammer
58. The Surface and Soil Temperatures of Putting Greens
59. The pH, N, P, and K of Putting Green Soils in 2012
60. The Ca, Mg, S, and Micronutrients of Putting Green Soils in 2012
61. Measuring the Reliability of Putting Greens
62. Putting Green Soil Moisture Content and Management in Summer
63. The Effect of Rolling on Green Speed and Green Hardness
64. Putting green surface temperatures and syringing
65. Fertilizer planning and nutrient mass balance
66. Green Speed Summary
67. Temperature-based growth potential: a study in 3 seasons
68. What is the effect of day length on turfgrass growth and nitrogen requirement?
69. Organic Matter Management in Putting Greens
70. When is the best time to core aerify putting greens?
71. A new way to look at turf nutrient requirements
72. A Method to Predict the Optimum Time for Overseeding
73. A counterintuitive approach to irrigation
74. An important note on the timing of growth regulator and nitrogen applications
75. Anthracnose and healthy greens in summer
76. New research about management of thatch and organic matter on putting greens
77. How many nutrient cations can a green hold?
78. Fertilizer, leaching, and cation exchange capacity
79. What do wetting agents really do?
80. Nitrogen fertilizer — when it is used by the grass?
81. Does nitrogen fertilizer increase or decrease roots?
82. Temperature, humidity, and combining them for summertime heat indices
83. Mowing and the 1/3 rule
84. Timing of nitrogen application to greens
85. Putting green performance tests: professional estimates
86. A new summary of putting green stimpmeter, surface hardness, and soil water measurements
87. Are summer nights getting hotter?
88. Fine fescue putting greens and tournament golf
89. Wind, tournament golf, and the 5 day Open Championship
90. Some useful things to understand about light
91. An analysis of three years of tournament green hardness data
92. An analysis of three years of tournament green speed data
93. What do P and K mean, exactly?
94. Two methods for precision water management
95. Course conditioning guidelines for PGA Tour tournaments
96. How much does water use vary from green to green?
97. The combination of temperature and sunshine to compare locations
98. What’s the irrigation water requirement?
99. Green speed, pace of play, and more green speed


A little more data to support an anecdote

Yesterday I wrote about soil organic matter decreasing over a 3 year period, even though the greens had only been cored twice in that time, and sand topdressing amounts had been reduced each year.

201305
17th green after coring in May 2013

When I think about reducing organic matter, I usually think of removal or dilution. Removal would be through coring or scarification; dilution would be by mixing sand with the organic matter.

Cored_dressed
12th green after 12 mm core aerification and topdressing in May 2013

But in this case, I think the organic matter in the soil is going down because the organic matter production is less than the organic matter decomposition. The reason I think this is simple. There hasn't been much removal or dilution of organic matter in the past 3 years, but the organic matter has still gone down.

2013_mow_14
The 14th green in August 2013

In the comments to yesterday's post, there was some discussion of layering if sand was not applied often enough. I agree that undesirable layering might occur, but only if the grass was producing organic matter faster than it was decomposing.

To put this into context, I added up the volume of clippings from the greens in 2015, to give some idea of the growth rate at which the maintenance work described yesterday has led to a decrease in soil organic matter.

Green_yield

Add that up for the year and it is 270 L/100 m2. Measurements of the fresh weight of clippings on these greens give 0.3165 kg for each liter of clippings, so that is 85 kg of fresh clippings per 100 m2. I expect these clippings are about 70% water and 30% dry matter, so I've estimated the dry weight of the clippings at 26 kg/100 m2.

That gives three estimates of how much the grass is growing at this location. Those numbers might be useful if you'd like to compare the growth of grass where you are.

As an aside, these types of calculations are how I estimate nutrient harvest. If you've been to one of my seminars about how to use the MLSN guidelines, I will have described that the use of the guidelines involves taking the amount the grass will use (I'll call that a), adding that to the amount I want to make sure remains in the soil, which is the MLSN guideline (I'll call that b). These values a and b, together, are the amount of an element we want to be sure is present. a + b represent the amount we want to have. The amount we actually have is measured by the soil test, and I call that c. It follows that the amount of an element required as fertilizer is the amount we want to have, minus the amount we do have, represented in an equation as a + b - c.


Data to support an anecdote

Last week I received the latest soil tests from Keya Golf Club, where Andrew McDaniel is the superintendent. I'm sharing the organic matter results from the greens, because I think they will be of general interest. This chart shows the soil organic matter % on the greens for samples taken in early 2013, 2014, 2015, and now 2016.

Om4years

Now for a bit of a tangent, and then back to the work that's been done at Keya since 2013. It would seem that not core aerifying, and not topdressing all the time, would be considered alternative maintenance. Another way to look at it is that the management of soil organic matter -- the amount of work required in that regard -- will be proportional to the growth of the grass.

I remember a conversation I had once during break time at a seminar in New Delhi. "Tifeagle and other ultradwarf bermudagrass varieties accumulate too much thatch," someone told me, "and will require almost constant and aggressive verticutting to keep it under control." I disagreed, pointing out that the amount of thatch (organic matter) control required will be related to how much the grass grows. "Tifeagle in Siberia won't produce any thatch at all," I said.

As an example, this is Zoysia japonica in late July in Yorkshire, surrounded by cool-season grasses. The zoysia is not producing much organic matter at all, and there's no need to verticut or topdress or core.

Zoysia

Another example: this is Penncross in Thailand. It germinates, but doesn't require mowing. If you can keep it alive, you certainly don't have to worry about organic matter management.

Penncross

Rather than prescriptive recommendations of surface area to be removed by coring (I've recommended this in the past) or the quantities of sand that should be applied as topdressing (I've also recommended this in the past), I now think it is more reasonable to consider the growth rate of the grass, and to manage the organic matter as required based on the growth rate.

Ideally, there will be no coring, minimal verticutting, and minimal topdressing. That's easier, and it causes less disruption to the playing surface. Such an approach may not be possible, but I prefer to have my ideal as great surfaces all the time, with minimal disruption, compared to the alternative ideal of great surfaces except when coring to remove x % of the surface area each year while applying a total of y mm of sand per year.

Back from that tangent to the greens at Keya, where the organic matter on greens has been going down since 2013.

18green

If one does a regression on these data, for each day that passes, the organic matter in the top 10 cm of the soil has gone down by 0.005 g per kg. In 365 days, the reduction is about 1.8 g/kg.

Here's where the data support an anecdote. The anecdote is, managing the growth rate allows one to minimize or eliminate coring.

The N rate on these greens in 2013, 2014, and 2015, respectively, has been 14.6, 9.5, and 10.6 g/m2. That is still enough to produce a dense korai turf (manilagrass or Zoysia matrella).

Tape

Coring and solid-tine aerification has been minimal and has decreased while the greens have only improved. 12 mm core in May 2013, 12 mm solid in July 2013, 12 mm core in June 2014, and 13 mm solid cross tine in July 2015. That's not much, and the organic matter is going down.

16green

Greens were verticut 3 times in 2013, 3 times in 2014,and 4 times in 2015.

Topdressing amounts have been 8 mm in 2013, 4.6 mm in 2014, and 3.8 mm in 2015.

You see the trend? Core aerification is done infrequently, sand topdressing is applied less and less, N fertilizer is applied at a reasonable rate, and the soil organic matter goes down. It's a viciously good cycle.


Animated charts showing photosynthetically active radiation for a year

I spoke at the Sustainable Turfgrass Management in Asia 2016 conference about light at different locations. The presentations slides can be viewed here, or embedded below. For more about the conference, which saw 278 delegates from 24 countries and 5 continents travel to Pattaya this year, see this post at the Asian Turf Seminar site.

Light is important. Without enough light, grass won't grow well. I suggested that "no-problem" daily light integral (DLI) values for putting greens of bermudagrass, seashore paspalum, and zoysiagrass, may be about 40, 30, and 20 respectively. And I showed what PAR is, and how PAR is measured in one second as the photosynthetic photon flux density (PPFD), and then how all the PPFD over the course of a day are added together to make up the DLI.

I showed charts for one day, and also animated charts that show PPFD and DLI for every day of the year. This chart shows the maximum expected PPFD by time of day, and maximum possible DLI by day of the year, at Tokyo and Bangkok if there were no clouds. You may need to click the browser's "refresh" button to play these animations.

Result

I wanted to visualize how these maximum possible values, on days when the sky is clear and about 75% of the extraterrestrial radiation reaches the earth's surface. To do that, I looked up the global solar radiation for Tokyo for every hour of 2015, converted those values to PAR units, and plotted them together with the maximum possible values assuming 75% transmittance of extraterrestrial radiation. That is plotted here.

Tokyo2015

I also explained that the global solar radiation has a large influence on the evapotranspiration (ET). I demonstrated this ET calculator that uses the Hargreaves equation to estimate the ET based on global solar radiation.


Burning grass

2015年度の「芝焼き」

今年の「芝焼き」は青空で風も少しあったので、とても良い芝焼き日和でした。様々な節分の行事が岡山県内であったようですが、約900人の方がご来園でした。昨日の雨で土が湿っていたので、蒸気が上がりやすかったようです。

Posted by 岡山後楽園 on Tuesday, February 2, 2016

Korakuen in Okayama is one the three great gardens of Japan, and I like it especially because of its expansive noshiba (Zoysia japonica) lawns. In early February every year, a shiba yaki (grass burning) ceremony is held at Korakuen, when the lawns are burned.

The video above shows the ignition of a lawn. The Facebook page of Korakuen has more photos of the shiba yaki ceremony this year.

今日は「立春」、昨日の芝焼きを終えて春を迎える準備がととのってきた岡山後楽園です。これから焼けた芝を掃きます。真っ黒な芝をみるのは、また来年です。

Posted by 岡山後楽園 on Wednesday, February 3, 2016

It is pretty amazing how strange it looks before the lawns start to grow again.

【後楽園広報スタッフ奮闘記】2月2日~4日、御南中学2年生が後楽園で職場体験でした。みんなの感想を、3人が選んだ写真とともに掲載します。~御南中学職場体験~<Wさん>実は私は鳥が苦手で、近くに行くのも嫌でしたが、ここに来てとて...

Posted by 岡山後楽園 on Wednesday, February 3, 2016

For more about grass burning in Japan, see:



A summary of photosynthetically active radiation for 1 year at Tokyo

image from www.flickr.com
This chart (download it here) shows the average photosynthetic photon flux density (PPFD) for each hour of 2015 at Tokyo. The daily light integral (DLI) is the number written in black at the top right corner of each facet in this chart.

One can get some idea of how the DLI changes seasonally and with cloudy weather; one can also see how the PPFD changes from sunny to cloudy days at different times of the year.


A chart of PPFD at two locations this year from January 1 through last Friday

The photosynthetically active radiation (PAR) changes through the day and through the year. The PAR is measured instantaneously for a duration of 1 second as the photosynthetic photon flux density (PPFD), and by adding up the PPFD for all the seconds in the day, one gets the daily total of PAR, which is called the daily light integral (DLI).

These charts show the average PPFD on an hour by hour basis. With a look at a chart like this, one can see:

  • how length of the day affects PAR, by looking at what time in the morning and what time in the evening the PPFD goes to 0.
  • how time of the day affects PAR, by looking at the change in PPFD hour by hour through the day.
  • how day of the year, and consequently sun angle, affects the PAR, by looking at the maximum values of PPFD at midday and seeing how they change through the year.
  • how clouds reduce the PAR, by comparing PPFD on sunny hours or days to PPFD on hours or days that don't have full sun. For more about sun and clouds and time of year, see these descriptive slides with data from 4 days in Tokyo this year: a sunny summer day, a very cloudy summer day, a sunny autumn day, and a partly sunny autumn day.

This chart shows, for every hour of this year through last Friday, the average PPFD for that hour at Tokyo (red) and at Watkinsville (blue). Each panel of the chart is a single day, and the DLI in units of mol m-2 d-1 is written on each panel, in red for Tokyo and in blue for Watkinsville.

image from www.flickr.com

There have been 296 days this year, through October 23. On one of these days, February 10, there were erroneous data at Watkinsville, so I don't have a DLI. That leaves 295 days with a DLI for both Tokyo and Watkinsville. These locations have similar temperatures, and similar latitudes. How do they compare for photosynthetically active radiation? There have been 115 days with a higher DLI at Tokyo than at Watkinsville, and 180 days with a higher DLI at Watkinsville than at Tokyo.

I've made a couple other similar charts. This one shows the average PPFD at Tokyo hour by hour this year through October 12. Because the chart shows data for only one location, I've used color to indicate the month.

image from www.flickr.com

And the next one is the same location and dates as the above, with the addition of the DLI written on each panel.

image from www.flickr.com

The Watkinsville data are from the US Climate Reference Network and the Tokyo data are from the Japan Meteorological Agency.


Why light is more important for ultradwarf than for bent: my presentations at the Japan Turf Show

I'm giving two presentations at the Japan Turf Show in Tokyo this week. In the first one, I explain why light, by which I mean photosynthetically active radiation (PAR), is more important for ultradwarf bermudagrass than it is for creeping bentgrass. I use data from Tokyo and from Watkinsville, Georgia, to demonstrate this and to point out the difference in PAR between Japan and the region of the USA with similar temperatures.

The slides for this presentation about light are available in English and in Japanese.

In a second presentation, I talk about management of ultradwarf bermudagrass greens, explaining how this species performs compared to creeping bentgrass in Japan, and how it should be managed.

The slides for this presentation about ultradwarf management are available in English and in Japanese.


"I'd be applying potassium all the time": Part 2

In Part 1, I explained that adding potassium (K) after every precipitation event of 25 mm (1 inch) or more at Minneapolis or Fukuoka would supply from 2 to 13 times more K than the grass could use. Since there is no benefit to adding more K than the grass can use, it doesn't seem that such post-precipitation applications are necessary.

How can one determine how much K the grass will use? This calculator does, predicting how much K is required as fertilizer, all while making sure plenty of K remains in the soil as a buffer even beyond the K that is used by the grass.

And now, this calculator is available in a Japanese version too.

Selection_033


Energy for growth, and weeds

Two things today are kind of related to this topic. One is this -- Jim Brosnan mentioned, and showed photographic evidence, that "weed pressure on Oahu never ceases to amaze."

And I had a conversation with a golf course designer about fine fescue as an infrequently mown rough, in what climates that species can work, and what happens when it is too hot for fine fescue. And I mentioned that one can plant a number of species other than fine fescue in a warmer climate, but the problem becomes one of "how can we find a ball" because there is a lot of energy for growth. Of course there are various techniques turf managers can use to solve that problem, but then the turf will be alive, but thin. It must be if one is going to find a ball in it.

Once there are voids, weeds have an opportunity to grow. Turf managers can solve this problem too, with herbicides, or with manual removal of weeds. But now comes another problem. That is erosion, in locations with substantial rainfall.

Anyway, it must be that the growth of plants (desired species, and weeds) is related to the energy available for the plants to grow. In general the hotter it is, the more energy there will be for weeds, so when one thins a low maintenance rough, the energy for weed growth or invasion is going to be more in a hotter climate than in a cool one. I looked up some data from Japan -- hour by hour data of temperature and global irradiance for 2014 at Sapporo, Tokyo, and Naha. Then I converted the irradiance to photosynthetically active radiation (PAR) using a factor of 2.04.

I looked only at day time, when the sun was above the horizon. And I arbitrarily cut the data to look only at those hours when the temperature was greater than or equal to 20°C. Then I added up all the light, and all the hours. This is a very rough index of how much energy there is for growth, especially for the weeds that will grow when it is hot. And it is a conservative estimate, because the night temperatures influence growth too, and so does the actual temperature. This is just a quick way to note the differences between locations.

At Sapporo in 2014, the cumulative sum of PAR for hours when the temperature was greater than or equal to 20°C was 3,781 mol m-2. Tokyo has 5,844, and Naha was 9,124. Oahu is considerably warmer than Naha, so it almost certainly would have more PAR than Naha at this cutoff value.

Just looking at the time, how many hours were there for weeds to grow well in these different locations, by looking at how many hours there were with a temperature at or above 20°C? At Sapporo, there were 1,365 of these hours; at Tokyo there were 2,503; and at Naha it was 3,805. Again, locations in Oahu would almost certainly be more than Naha.

That is a real quick estimate of how much energy there is for weeds to grow, or more specifically how the energy is likely to differ in magnitude from location to location.

And one more thing -- in Scotland where a fine fescue rough actually works well, how much energy would there be for weeds? I don't have the exact irradiance data for Scotland, so I won't try to compare it to exact measurements. But I can give some idea of just how much lower the energy is, or how much lower the duration of time would be for weeds to grow rapidly. Huge disclaimer is necessary here, because the species are different, so a C3 weed like Poa annua might grow relatively rapidly in Dornoch but I am considering more the C4 weeds like Paspalum dilatatum or Cyperus rotundus.

It still makes an interesting comparison. Of Naha, Tokyo, and Sapporo, Sapporo is by far the coldest. And in the hottest month of the year in Sapporo, the average low temperature is 19.1°C, and the average high temperature is 26.4°C. How about somewhere in Scotland where fine fescue grows well? I picked Leuchars, just north of St. Andrews. In the hottest month of the year in Leuchars, the average low is 10.8°C, and the average high is 19.2°C.