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June 2016
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July 2016

A hypothesis about the most sustainable grass

I've written about zoysia growing faster than bermuda. Mike Richardson asked "is that better? Slow growing has always been one of my favorite traits of zoysia."

I answered that it is better, and that I would explain my hypothesis later. Here it is:

The most sustainable grass for a given location is the one that has the most growth per unit of N and per unit of H2O applied.


  • most sustainable grass is the one that requires the fewest inputs to produce the desired surface
  • location is the temperature and light combination. For more about this see


  • one considers all the grasses that could possibly produce the desired surface at that location
  • from those, one selects those that don't die when N and H2O are reduced

It follows that of the remaining grasses -- those that don't die -- the one with the fastest growth rate will require the fewest inputs to produce the desired surface, because one can supply low amounts of N and water to that grass. The one with the fastest growth rate also gives the most maintenance options, because one can adjust the growth rate across a wider range.

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."


Soil temperature and fairway management from 1980

I don't recall what I was searching for, but I stumbled fortuitously across this article by Oscar Miles from the Green Section Record in 1980:

Soil temperature and related fairway management practices -- northern turfgrasses

It's a great read, and quite interesting to see how he anticipated so much of the maintenance as conducted today.

"The additional data, I believe, will help us set up a program that a data processor or computer can maintain for us. I feel it is inevitable that mini-computers will make their way into golf course management systems. This is not as far-fetched as you might think."


p.s. Now I recall. I probably was searching for something related to soil water content and nighttime soil temperatures in summer.

Turfgrass and shade: daily light integral (DLI) in Sydney

The Australian Government Bureau of Meteorology (BOM) provide satellite-derived global solar radiation data. I downloaded 2015 and 2016 data for station number 66120 (Gordon Golf Club). The data are in energy units of megajoules per square meter per day. I multiplied by 2.04 to convert to daily light integral (DLI) units of moles per square meter per day.


This is the DLI in full sun, adjusted for clouds. Any tree or structural shade will result in a lower DLI.

Looking at monthly summaries of DLI, one can see the median and the normal range in each month since January 2015.



I downloaded temperature data from the Sydney Airport (SYD) and used those to calculate an estimated DLI using the Hargreaves equation, as described in Estimating daily light integral in 4 Tennessee cities. I did not make any corrections to the estimate from the Hargreaves equation, and SYD is about 25 km south of Gordon. Still, the uncorrected Hargreaves equation gives a decent estimate of DLI.


Monthly Turfgrass Roundup: June 2016

Here's a roundup of turfgrass articles and links from the past month:

Kreuser with a cool video of syringing to cool turf:

Silvertown on Agatha Christie and Park Grass.

MLSN data and code.

The preprint about the MLSN guidelines was published.

Sand as a finite resource in the NY Times.

TPC Piper Glen with decades of aerification holes:

99 articles titles from Golf Course Seminar (Japan).

Robertson showed how to double cut and triple roll:

Does soil water content affect nightime soil temperatures in summer?

Six Shiny apps for making turfgrass calculations.

Daily light integrals (DLI) for warm-season putting green grow-in.

For more about turfgrass management, browse articles available for download on the ATC Turfgrass Information page, subscribe to this blog by e-mail or with an RSS reader - I use Feedly, or follow asianturfgrass on Twitter. Link and article roundups from previous months are here.