I discussed grass responding to P at establishment, but not at maturity, as a function of soil P combined with rootzone volume. 

Posts discussed are:

• https://www.asianturfgrass.com/post/rootzone-volume-and-p/
• https://www.asianturfgrass.com/post/algae-sand-fertilizer/
• Find a suite of decision-making tools at https://www.paceturf.org/
• Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/
• Get free newsletters at https://www.asianturfgrass.com/newsletter/

Find out more about soil tests with ATC at https://www.asianturfgrass.com/project/soil-tests/

The topic of nutrient availability and extractable vs. exchangeable vs. available nutrients used to come up a lot, and I'm glad I haven't been asked this question as frequently in recent years. Fortunately, I have a long list of blog posts about this topic, and a good starting point is the one reviewed in this episode : https://www.asianturfgrass.com/post/its-not-really-about-extractable-or-available/

• Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/
• Find a suite of decision-making tools at https://www.paceturf.org/
• Get free ATC newsletters at https://www.asianturfgrass.com/newsletter/

Find out more about soil tests with ATC at https://www.asianturfgrass.com/project/soil-tests/

This episode discusses Grime's definition of stress as "external constraints which limit the rate of dry matter production" and how this is related to nutrient supply/demand/requirement for fine turfgrass.

• The post discussed is https://www.asianturfgrass.com/post/does-stressed-turf-require-more-or-fewer-nutrients/
• Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/
• Find a suite of decision-making tools at https://www.paceturf.org/
• Get free ATC newsletters at https://www.asianturfgrass.com/newsletter/

Find out more about soil tests with ATC at https://www.asianturfgrass.com/project/soil-tests/

I looked at sand particle sizes at the top of putting green rootzones, and compared those particle sizes to what is in the sand topdressing. The average results of this analysis are presented in this episode.

• The chart discussed is available at https://www.paceturf.org/gallery/detail/particle-size-change-from-topdressing-to-om2
• Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/
• Find a suite of decision-making tools at https://www.paceturf.org/
• Get free ATC newsletters at https://www.asianturfgrass.com/newsletter/

Find out more about soil tests with ATC at https://www.asianturfgrass.com/project/soil-tests/

I looked at the temperatures and dew points for a range of cities around the world during the first month of the most recent meteorological summer. June 2026 in the northern hemisphere, and December 2025 in the southern.

The blog post discussed is: https://www.asianturfgrass.com/post/first-month-of-summer-dew-point-depression/

Also see the day in that month with the highest average dew point: https://www.paceturf.org/gallery/detail/first-month-of-summer-2026-maximum-dew-point

• Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/
• Find a suite of decision-making tools at https://www.paceturf.org/
• Get free ATC newsletters at https://www.asianturfgrass.com/newsletter/

Find out more about soil tests with ATC at https://www.asianturfgrass.com/project/soil-tests/

The firmness of putting greens varies with the surface organic material. More organic material in the top 2 cm (0.8 inches), and greens are softer. I discuss terminology, the relationship between firmness and organic material, and what you can do about this.

• The blog post discussed is https://www.asianturfgrass.com/post/om2-and-firmness/
• Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/
• Find a suite of decision-making tools at https://www.paceturf.org/
• Get free ATC newsletters at https://www.asianturfgrass.com/newsletter/

Find out more about soil tests with ATC at https://www.asianturfgrass.com/project/soil-tests/

I've updated my recommendation for the sand quantity to apply for every unit of clipping volume harvested, if your goal is to keep surface organic material constant. Bjarni and I discussed topdressing by this method and the new equation that finds this sand amount.

• We discussed this post: https://www.asianturfgrass.com/post/sand-topdressing-ratios-clipping-volume/
• The PACE Turf table of sand rates based on surface organic material is at https://www.paceturf.org/public/sand-and-clipping-volume
• Bjarni and I discussed the spring green-up and growth from adding sand: https://www.asianturfgrass.com/post/turfgrass-mystery-the-case-of-the-greener-grass/
• Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/
• Find a suite of decision-making tools at https://www.paceturf.org/
• Get free ATC newsletters at https://www.asianturfgrass.com/newsletter/

Find out more about soil tests with ATC at https://www.asianturfgrass.com/project/soil-tests/

This is about partitioning the growth flush after a rain. What's causing that growth flush? I made some calculations, using New Forest GC in the UK as an example. The increased soil water content from a 20 mm rain, in this example, would increase daily clipping volume from 10 mL/m2 to 22 mL/m2, a 12 mL increase.

• The blog post discussed is https://www.asianturfgrass.com/post/nitrogen-in-rain-or-nitrogen-from-the-soil/
• See also https://www.asianturfgrass.com/post/how-much-n-is-in-rain-and-snow/ for information on atmospheric deposition of N
• Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/
• Find a suite of decision-making tools at https://www.paceturf.org/
• Get free ATC newsletters at https://www.asianturfgrass.com/newsletter/

Find out more about soil tests with ATC at https://www.asianturfgrass.com/project/soil-tests/

It sounds counterintuitive at first, that you can maintain a lower average water content in the soil, and a higher air content in the soil, by applying irrigation every day. Once upon a time, I thought the way to keep soils drier and with more air was to implement deep and infrequent irrigation. 

• The blog post discussed is: https://www.asianturfgrass.com/post/deep-and-infrequent-or-light-and-frequent-irrigation-which-is-better/
• I also mentioned John Jordan's research, see: https://tic.msu.edu/tgif/flink/RECNO/59354
• Paul Johnson article about irrigation frequency: https://usgatero.lib.msu.edu/v02/n06.pdf
• Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/
• Find a suite of decision-making tools at https://www.paceturf.org/
• Get free ATC newsletters at https://www.asianturfgrass.com/newsletter/

Find out more about soil tests with ATC at https://www.asianturfgrass.com/project/soil-tests/

Brian Whitlark joined me to talk about sand topdressing of putting greens and especially about sand amounts.

• The blog post we discussed is: https://www.asianturfgrass.com/post/standard-sand-amounts/
• Listen to Brian's recent appearance on the Frankly Speaking podcast: https://podcasts.apple.com/lt/podcast/firm-fast-desert-with-brian-whitlark/id1793571091?i=1000743219832
• OM246 calculator web app with sand quantity conversion calculator: https://asianturfgrass.shinyapps.io/om246/
• How to measure topdressing rates: https://youtu.be/6LurONpyg5M?si=LW4IPwzzXbVAOn-m
• Managing salinity in putting greens article by Brian: https://www.usga.org/content/usga/home-page/course-care/green-section-record/64/issue-08/managing-salinity-in-putting-greens.html
• Terminology of turfgrass organic matter: https://youtu.be/tMfby5xR2IM?si=8aOQ-Ju6A_cLib8M
• Whitlark and Thompson article from 2019 on topdressing: http://gsrpdf.lib.msu.edu/ticpdf.py?file=/article/whitlark-thompson-light-5-3-19.pdf
• Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/
• Find a suite of decision-making tools at https://www.paceturf.org/
• Get free ATC newsletters at https://www.asianturfgrass.com/newsletter/

Find out more about soil tests with ATC at https://www.asianturfgrass.com/project/soil-tests/