Turfgrass Information

A couple new things, and a reminder of an old one

When I saw that Brad Revill had started a blog, I was intrigued, because there are not many blogs written by turf managers in the tropics. I was even more intrigued when I saw that the title of his very first post was The start of something new -- MLSN!!. He wrote:

For years I have been following the recommendations from soil testing laboratories trying to create the "ideal soil" with the correct ratios of nutrients. After each soil test I would follow the recommendations, most of the time adding more and more calcium. After each test my ppm values would increase along with the "target" ppm values which kept getting higher and higher until it seemed I would never reach it. I grew frustrated with the recommendations and after reading article after article and research papers online, I came across the MLSN guidelines produced by Pace Turf and Dr. Micah Woods.

That's a new blog that I expect will be quite interesting to read.

Now for my annual reminder of an excellent resource, the Golf course management blogging world site. This site aggregates blogs from around the world and shows the most recent updates at the top.


The site administrators sometimes make manual updates to confirm the feeds are correct and the code is updated. I'm hoping they will do a refresh on the site again this winter to make sure all the feeds are active.

And one more thing. If you are really wanting to read about turf, I have updated my last blog post about an eclectic reference list, so that each article or book that I cited now has a link to the item. I cited articles from 1859 until 2012, and you can get the full text of most of the items for free. Have a look, and see if you find anything interesting.

High expectations


I've rarely been so excited to read an article. Last week when I saw Energy use and greenhouse gas emissions from turf management of two Swedish golf courses, by Tidåker et al., I immediately dropped what I was doing and read it.

If you've talked with me about turfgrass management sometime in the past 18 months, our conversation may have touched on differences in energy use, and the difference in carbon emissions, caused by differences in grass selection and maintenance practices. In fact, this is one of the topics Dave Wilber and I discussed as part of our wide-ranging conversation during episode 14 of the Turfgrass Zealot Project. I don't know how to make these calculations yet, but finally with this article I've read something that provides the calculations, and that I can study so I can figure out how to do this myself.

Gelernter et al. wrote in 2014 about quantifying sustainability on golf courses. We suggested measuring and tracking the annual:

  • quantity of fertilizers applied
  • quantity and toxicity of pesticides applied
  • quantity of water used
  • fuel volume
  • labor hours
  • electricity used

One can keep track of those quantities, together with the associated costs, and from that one can check the efficiency of the operation. These quantities also serve as some of the basic data requirements for the GEO OnCourse program.

But the quantities we wrote about in the GCM article are all different: kg of N, kg of fungicide, L of water, L of diesel, kWh of electricity. By expressing all the turf maintenance activities in units of greenhouse gas emissions (expressed as CO2 equivalents) or energy use, one then has a single number for the entire course, or for an area of the course, or per square meter, that can be used to compare to other courses next door or around the world. And the use extends well beyond comparisons to other golf courses; one can use these units to compare the maintenance of a golf course to anything that has greenhouse gas emissions or energy use.

I had high expectations for the article, and I wasn't disappointed. The authors described the fertilizer rates, topdressing rates, water use, mowing frequencies, and much more, for the two courses, and then expressed those units in GHG or energy use. N rates were up to 22 g/m2, as were K rates (I think the rates for golf course turf in Sweden should usually be less than reported in the article -- using precision fertilization, or temperature-based growth potential and MLSN, will lead to lower recommended amounts of fertilizer). Sand topdressing on greens was about 10 mm/year. Irrigation of greens was about 300 mm/year. Mowing of fairways was about 85 times/year, and greens were mown about 180 times/year.


I think this is fascinating because one can consider Sweden to have relatively low inputs. If you're familiar with golf course maintenance in a tropical environment, let's say in Phuket, you might expect fairways to be mown more than 150 times a year, greens more than 300 times, about double the fertilizer, and more than twice the water use. Now imagine what happens when comparing irrigated vs non-irrigated rough? Seashore paspalum wall-to-wall vs. manilagrass? A 60 ha sandcapped golf courses vs. one with drainage and 2 cm of sand topdressing? Overseeded vs. not? The differences in energy use and greenhouse gas emissions will be huge.

What did Tidåker et al. find in their analysis? The entire paper is worth a careful study, but in summary they found mowing was the most energy-consuming activity, and mowing together with the production and application of fertilizers (especially N) contributed the most to greenhouse gas emissions. They suggest:

Appropriate measures for reducing energy use and carbon footprint from lawn management are thus: i) reduced mowing frequency when applicable, ii) investment in electrified machinery, iii) lowering the mineral N fertiliser rate (especially on fairways) and iv) reducing the amount and transport of sand for dressing. Lowering the mineral fertiliser rate is of particular importance, since GHG emissions originate from both the manufacturing phase and from N turnover after application.

Jason Haines has some interesting reads about how turf condition can be improved while at the same time reducing inputs:

Both of these are worth your time

One is an article, another is a podcast, and you won't regret the time spent reading the first and listening to the second.

First, the 4 November issue of the Green Section Record contains Managing Organic Matter in Putting Greens by Adam Moeller and Todd Lowe.

This article explains that "there are many agronomic programs that influence the playability and health of putting greens, but organic matter management is arguably the most important." It goes on to explain the standard practices in 2016.

Moeller and Lowe conclude that "traditional programs", and by that they mean programs that include core aeration, "still provide the most consistent results for managing organic matter and improving putting green conditions."

This is a really good article for referencing what is standard in 2016, but I'm not in full agreement with their conclusion. I used to think that coring was essential, but over the past few years I've changed my thinking. More about that in the footnote.

The second item is the recent TurfNet Radio podcast with Frank Rossi and Chris Tritabaugh about managing for the Ryder Cup. If you listen to this, you will find that they discuss organic matter on putting greens (and a lot of other interesting things), but if you haven't heard, there has been no core aeration on the greens at Hazeltine since 2013.

The article says coring provides the most consistent results, and the podcast explains how greens are managed to a high standard without coring. It's good to be informed about this topic, so that you can be sure to make the right choices for any turf that you manage.

Footnote: I used to recommend the removal of 20% of the putting green surface area by coring each year and the annual addition of at least 12 mm of sand topdressing. I don't make that recommendation anymore.

Rossi and Tritabaugh talked about the grass yield and growth rate. How much was the grass growing? The idea being that one can match the quantity of sand applied to the rate of grass growth, thus avoiding coring by maintaining a consistent organic matter content at the soil surface. But they did not put a number to the growth rate. I think it is possible to put a number to the growth, and from that to make a site specific plan for organic matter management.

Consider the "new" bentgrasses with high shoot density, or ultradwarf bermudagrasses, widely considered to be prolific thatch producers. Please consider now how much thatch bentgrass will produce in Bangkok, or how much organic matter Miniverde will produce in Moscow. None, right? Now please continue that thought experiment a step further, and consider how much thatch (or organic matter) grasses produce when they grow slowly, supplied with just enough nitrogen and just enough water to produce the desired growth rate. Supply no N and no H2O to ultradwarf bermudagrass and there won't be any organic matter to manage. Is it possible that there is a level of growth at which minimal topdressing and no coring produce the desired surface? That's the goal, and I think it is possible with careful attention to the growth rate.

And that avoids (or at least minimizes) the putting surface disruption associated with coring too.

For more about this, see:


New paper on variability of hybrid bermudagrass used on putting greens

If you work with warm-season grasses, you will want to have a look at this new paper by Reasor et al. on the variability of hybrid bermudagrasses used on putting greens.


Ever see anything like this? Off-types growing in a green? Wondered if the off-types are contamination by a completely different grass, or if the grass has mutated?


This paper explains what can happen, what has happened, and why. Plus it has a historical review of these hybrid bermudagrasses used on greens. Find out where they came from and how the grasses are related.

ReasorSometimes I write about papers that are behind a paywall and most people can't read (or at least don't want to pay the high fees to purchase). I'm glad there won't be that problem with this article, as Reasor et al. have published this open access so everyone can read it.

I've just spent a couple weeks with the lead author Eric Reasor (pictured at right in Japan) collecting data from bermudagrass putting greens in Asia.

He's been doing a lot of interesting research about ultradwarf bermudagrass, off-types within those grasses, and the management of putting greens to minimize problems with off-types. Watch out for more interesting research from him on this topic.


Two fine articles about two important topics

When I visit Japan, I like to try the various flavors of soft ice cream as I go to different places. This is peanut soft cream in Chiba prefecture.


Another thing I like to do is browse the magazines to find interesting articles. I had a chance to see recent issues of Monthly Golf Management this week, and I was pleased to see two articles that I recommend in English are now available in Japanese.


If you are in Japan, read them in the magazines. For the original versions, if you haven't read them yet:

How to develop a water budget for your golf course: "How much water does your golf facility need each year to keep the turf healthy?"

Turfgrass fertilization: "supplemental nutrition is typically necessary to strengthen critical plant components so turf can provide desirable playing surfaces ... This article covers several aspects of turfgrass nutrition, such as determining how much fertilizer is actually needed, fertilizing for enhanced playability, the economics of turfgrass fertilization, and dispelling some of the myths surrounding fertilizer applications."


99 article titles


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

How to save 82% on fertilizer cost

There is another good article in the Green Section Record, this one by Blake Meentemeyer and Brian Whitlark on Turfgrass Fertilization. You'll want to read the full article. It talks about the overall goals of fertilizer application, soil tests, some myth busting, fertilizer and playability, and more. It's a modern article with a lot of historical references too.

The most interesting part of the article for me was the economic case study. A course reduced the putting green fertilizer cost by 82% and the result was "the putting greens have never been healthier."

For more about this topic, see How to save 60% or more in turfgrass fertilizer cost.

Every spring when the snow melts ...

I look forward to some photos from Doug Soldat. For the past three years, he's had some fascinating photos to share of snow mold on creeping bentgrass. And each year, there was more snow mold where potassium fertilizer was applied, and less snow mold where potassium wasn't applied.

Spring of 2014

In the spring of 2014, there was more snow mold where K was applied.

Spring of 2015

Last year, there was also more snow mold where K was applied.

Spring of 2016

This year, it happened again. There was more snow mold where K was applied.

Doug will be talking about K in a TurfNet webinar in April: Is Your Potassium Program Hurting or Helping Your Turf?

On those creeping bentgrass plots in Wisconsin, adding K increases snow mold. No K had less snow mold.

At Rutgers, annual bluegrass plots deficient in K have had more anthracnose in summer and more winter injury. Eliminating the deficiency reduced those problems.

Then there is the MLSN guideline for K of 37 ppm. I recommend keeping the soil K above 37 ppm (Mehlich 3 extractant).

And there are hundreds of other studies about K. Some show a benefit from adding K, and some don't. I haven't read all of them, but I have read a lot of them. This sounds like it could be pretty complicated.

Actually, I don't think it is. Here's what seems to be the case, for both warm-season and cool-season grasses:

Ensuring the grass is supplied with all the K it can use will provide all the benefits associated with K. Adding more than that usually has no effect, other than wasting time and money, but sometimes has a negative effect.

As a turfgrass manager, all one has to do is ensure the grass is supplied with all the K it can use. This can be accomplished in 2 ways. One is by keeping the soil K above the MLSN guideline. A second is by applying N:K in a 2:1 ratio for cool-season grasses, a 1:1 ratio for seashore paspalum, and a 3:2 ratio for other warm-season grasses. I wrote about that in the final chapter of A Short Grammar of Greenkeeping and in The (New) Fundamentals of Turfgrass Nutrition.

Note that I do not recommend tissue testing for K (or any other element).

If you want to read more about K specifically, and about how the benefits of K come from correcting a deficiency, I recommend:

"Which products and technologies are truly beneficial and cost-effective?"

This is an article I've recommended before, and share again here. It is Purchasing new products and technologies: an ethical and common-sense approach by Dr. Robert Carrow.


Dr. Carrow explains a procedure for golf course superintendents who want to stay on the cutting edge of advancements to make "wise decisions about purchasing new products/technologies." He explains the ethical aspect, the need for information, and the application of common sense.

Regarding ethics of purchasing, he writes:

Specific science-based information is often limited or lacking for many new products/technologies. Substituted for testing and evaluation may be manufacturer claims, testimonials, and psuedoscience (claiming a product can theoretically provide a response while knowing that the magnitude is very small, or providing "selected" data to support a claim while withholding data that proves otherwise).

Why is this an ethical issue? He explains it like this (italics his):

The ethical point is that golf club officials assume that the golf course superintendent is making science-based decisions on new products/technologies when spending their money ... Thus, expending large amounts of club funds for testing a new technology is an ethical issue when the decision is based on "I hope" rather than "I know" and the club bears the total cost if the technology fails to perform.

For information, Carrow gives seven questions that superintendents should ask themselves:

  1. Is this product needed in my situation?
  2. Are there better "alternatives"?
  3. Is the positive response due to the "active ingredient" or to an added material?
  4. How important is the response?
  5. Are valid, unbiased "test results" available?
  6. Should I try this item on a trial area or basis?
  7. Do the "benefits" justify the costs?

He gives lots of examples too -- read the article to see the types of products he mentions, like humic acid and humate products, acidifying soils or water, the addition of Fe and N to many products, microorganism addition, water treatment devices ...

He says the bottom line is whether the benefits to the golf facility justify the cost. Ask this question to yourself, he suggests, concerning the cost and benefit: "Would I purchase this product or technology with money from my personal bank account if I were the owner?"

Take ethics and information, add in a little common sense, and you'll be on the cutting edge.