Turfgrass growth potential and measuring clipping volume

These slides were used to introduce and explain the magic of a temperature-based turfgrass growth potential. One can get a starting point estimate of turfgrass nutrient use by what seems like magic, starting with high and low daily air temperatures and ending up with, for example, a daily or weekly or monthly expected magnesium use by the grass. I then went on to explain that one can measure what actually does happen by measuring the clipping volume of the grass as it is mown.

Transcript

1. Turfgrass growth potential and measuring clipping volume Micah Woods 13 December 2018 Chief Scientist Asian Turfgrass Center www.asianturfgrass.com
2. Temperature-based growth potential
3. Grasses can grow well when temperatures are close to an optimum for growth, and grasses grow more slowly as the temperature moves away from the optimum.
4. Temperature-based growth potential PACE Turf developed the Temperature-based GP to express the actual temperature in terms of its proximity to optimum temperatures for shoot growth. GP = e−0.5( t−to var )2 where, GP = growth potential, on a scale of 0 to 1 e = 2.71828, a mathematical constant t = average temperature for a location, in celsius 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
17. Implications and use of GP • mowing frequency • fungicide duration • heat-related stress • topdressing requirement • nutrient use
18. Measuring clipping volume
20. Use of clipping volume 1. Growth rate
21. Use of clipping volume 1. Growth rate 2. Green speed
22. Use of clipping volume 1. Growth rate 2. Green speed 3. Nutrient use and supply
23. Use of clipping volume 1. Growth rate 2. Green speed 3. Nutrient use and supply 4. Consistency
24. Use of clipping volume 1. Growth rate 2. Green speed 3. Nutrient use and supply 4. Consistency 5. Topdressing
25. 1. Growth rate
26. Old Course, St. Andrews
27. Kashima Soccer Stadium, Japan
28. Royal Bangkok Sports Club
29. Siam CC Plantation Course, Thailand
30. 2. Green speed
31. greenkeeper Andrew McDaniel (@drumcturf) at Keya GC, Japan
32. Keya GC, Japan
39. Keya GC, Japan
40. Keya GC, Japan
43. Eric Reasor project, photo at Koshigaya GC, Saitama, Japan
45. 3. Nutrient use and supply
46. Nichino Ryokka research center at Chiba, Japan
47. Chiba, Japan
49. For bentgrass, with every 10 mL/m2, expect a dry matter harvest of 0.6 g/m2.
50. Then resupply as desired For example, 200 mL/m2 of bentgrass ≈ 0.5 g N/m2. And 0.25 g K/m2. And so on.
52. 4. Consistency
53. Augusta National GC, USA
54. Keya GC, Japan
59. 5. Topdressing
60. Tifeagle, Thailand
61. “41% of members and players complain that sanded greens play poorly, according to turf managers who participated in recent GCI research.” GCI Magazine—April 2018
62. Kanto region, Japan
67. Table 1: Annual clipping volume at that location from 2013 to 2016 Year Volume Estimated dry weight N applied L/m2 g/m2 g/m2 2013 4.4 266 NA 2014 3.4 201 13 2015 2.9 172 10 2016 2.4 142 8.5
68. For more, please see www.asianturfgrass.com.