If turfgrass growth were a recipe, these are the ingredients

In this presentation, I discuss the four environmental factors, or ingredients, that have a controlling effect on turfgrass growth. These are light, specifically the photosynthetically active radiation; the temperature; the plant water status; and the leaf nitrogen content. All of these factors influence the growth rate of the grass, and I discuss how greenkeepers can understand, measure, and monitor these factors.

Transcript

1. If turfgrass growth were a recipe, these are the ingredients Micah Woods Asian Turfgrass Center www.asianturfgrass.com 28 September 2015
2. The 4 “ingredients” of growth One can either control or measure all of the “ingredients.”
3. The 4 “ingredients” of growth One can either control or measure all of the “ingredients.” ▶ Temperature
4. The 4 “ingredients” of growth One can either control or measure all of the “ingredients.” ▶ Temperature ▶ Water
5. The 4 “ingredients” of growth One can either control or measure all of the “ingredients.” ▶ Temperature ▶ Water ▶ Light
6. The 4 “ingredients” of growth One can either control or measure all of the “ingredients.” ▶ Temperature ▶ Water ▶ Light ▶ Nitrogen
7. Fukuoka prefecture
8. Shimane prefecture
9. Obihiro, Hokkaido
10. Fukuoka prefecture
11. Tomakomai, Hokkaido
12. -10 0 10 20 30 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 Temperature (°C) Sapporo 2014
13. The turfgrass growth potential (GP) Cool-season grass is expected to have its best growth when mean temperature is from 16 to 24℃. GP = e−0.5(t−to var )2 GP = growth potential, on a scale of 0 to 1 e = 2.71828, a mathematical constant t = average temperature for a location, in ℃ to = optimum temperature, 20 for C3 grass, 31 for C4 grass var = adjusts the change in GP as temperature moves away from to ; I suggest 5.5 for C3 and 7 for C4
14. 0.00 0.25 0.50 0.75 1.00 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 Growth potential (GP) Sapporo 2014
15. 0 20 40 60 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 Daily precipitation (mm) Sapporo 2014
16. 0 250 500 750 1000 1250 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 Cumulative precipitation (mm) Sapporo 2014
17. 0 2 4 6 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 Daily ETo (mm) Sapporo 2014
18. 0 200 400 600 800 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 Cumulative sum of ETo (mm) Sapporo 2014
19. -60 -40 -20 0 5 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 Daily ETo - precipitation (mm) Sapporo 2014
20. -400 -300 -200 -100 0 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 Cumulative sum of ETo - precipitation (mm) Sapporo 2014
21. PAR, PPFD, DLI What do these mean? ▶ PAR is photsynthetically active radiation. It is the light with wavelengths from 400 to 700 nm. ▶ PAR is measured instantaneously as a flux of photons within those wavelengths on a surface of 1 m2. ▶ Instantaneous PAR is the photosynthetic photon flux density, (PPFD). ▶ Adding together all the PAR from each second of the day gives the daily light integral, DLI.
22. 0 20 40 60 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 Max possible DLI Sapporo 2014
23. 0 20 40 60 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 Actual DLI Sapporo 2014
24. 0.25 0.50 0.75 1.00 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 DLI index Sapporo 2014
25. 0.00 0.25 0.50 0.75 1.00 Jan 2014 Apr 2014 Jul 2014 Oct 2014 Jan 2015 shade index Sapporo 2014
26. Nitrogen ▶ Nitrogen is the one factor influencing growth that greenkeepers can control. ▶ The nitrogen supply to the grass will be proportional to a combination of temperature, plant water status and light, adjusted for the site-specific requirement for growth.
27. Thank you. speakerdeck.com/micahwoods