Soil conditions for the best turf today

These slides were used in my presentation at the Oregon GCSA fall meeting. With Larry Stowell and Wendy Gelernter from PACE Turf, I helped to conduct the Global Soil Survey (GSS). This project invited turfgrass managers from around the world to submit samples from good-performing turf at their facilities. Based on an analysis of the properties of these samples, I have many interesting things to explain and to suggest about turfgrass nutrient management.

This is a different project than the well-known MLSN, although I’ve heard some people use the GSS and MLSN interchangeably. I explain exactly what the GSS is, what the results were, how the results compare to MLSN, and what the implications are for fine turf management in the current era.

Transcript

1. What kind of soils produce the best turf today? Micah Woods Chief Scientist Asian Turfgrass Center www.asianturfgrass.com November 6, 2019
2. 1. Which data will we look at? 2. How will we look at the data? 3. Implications for pH, OM, K, P, Ca, Mg, salinity, micronutrients, and N
3. Which data will we look at?
5. GSS kit, good performing turf
6. GSS sample locations, 2013 to 2016
7. Samples collected from good performing turf
8. How will we look at the data?
9. Golf scores as an example Ile aux Cerfs Golf Club, Mauritius
10. 87 92 86 81 87 83 86 91 86 84 82 84 86 88 90 92 18 hole score 10 random golf scores
11. 82 84 86 88 90 92 18 hole score Dotplot of 10 random golf scores
12. 0 1 2 3 80 82 84 86 88 90 92 18 hole score count bin width = 1 Histogram of 10 random golf scores
13. 0 1 2 3 4 5 80 82 84 86 88 90 92 94 18 hole score count bin width = 3 Histogram of 10 random golf scores
14. 87 92 86 81 87 83 86 91 86 84 88 86 81 84 87 86 87 80 88 81 81 89 87 89 75 81 86 85 87 81 90 82 83 84 87 94 84 92 81 85 88 93 80 83 82 81 92 85 79 89 81 83 87 80 96 79 83 82 87 84 86 82 85 89 88 87 81 76 86 84 91 82 84 81 74 78 84 81 83 91 88 87 91 84 86 88 83 87 87 87 86 89 81 78 82 78 91 89 90 83 74 76 78 80 82 84 86 88 90 92 94 96 18 hole score 100 random golf scores
15. 74 76 78 80 82 84 86 88 90 92 94 96 18 hole score Dotplot of 100 random golf scores
16. 0 5 10 74 76 78 80 82 84 86 88 90 92 94 96 18 hole score count bin width = 1 Histogram of 100 random golf scores
17. 0 10 20 30 74 76 78 80 82 84 86 88 90 92 94 96 98 18 hole score count bin width = 3 Histogram of 100 random golf scores
19. Implications for pH, OM, K, P, Ca, Mg, etc.
20. median: 6.5 min: 4.6, max: 8.2 0 5 10 15 20 25 5 6 7 8 Soil pH in 1:1 H2O count pH
21. median: 1.76 min: 0.17, max: 10.15 0 5 10 15 20 0.0 2.5 5.0 7.5 10.0 Soil organic ma er percent by weight count OM, all samples Loss on ignition at 360 C
22. median: 1.44 min: 0.17, max: 4.69 0.0 2.5 5.0 7.5 10.0 0 1 2 3 4 Soil organic ma er percent by weight count OM, pu ing green samples Loss on ignition at 360 C
23. ▶ Soil organic matter is about 5% N. From 1 to 4% of that N is expected to become plant available each year. ▶ That gives an estimate of about 0.4 lbs N/1000 ft2 expected release each year from the top 4 inches of soil for each 1% of soil organic matter. ▶ With the average OM in putting green soils, N release is expected to be about 0.6 lbs N/1000 ft2.
24. median: 60 min: 10, max: 296 0 5 10 15 20 25 0 100 200 300 Soil K in ppm count Potassium Mehlich 3 extraction
25. median: 60 min: 10, max: 296 86 percent below 0 5 10 15 20 25 0 100 200 300 Soil K in ppm count Potassium Mehlich 3 extraction
26. Soil K about 60 ppm
27. median: 68 min: 6, max: 450 38 percent below 0 10 20 30 0 100 200 300 400 Soil P in ppm count Phosphorus Mehlich 3 extraction
28. median: 585.5 min: 125, max: 2844 58 percent below 0 5 10 15 20 0 1000 2000 3000 Soil Ca in ppm count Calcium Mehlich 3 extraction, calcareous samples removed
29. median: 74 min: 23, max: 516 79 percent below 0 10 20 30 0 100 200 300 400 500 Soil Mg in ppm count Magnesium Mehlich 3 extraction
30. median: 0.66 min: 0.5, max: 1.5 100 percent below 0 10 20 30 40 0.0 0.5 1.0 1.5 2.0 Soil salinity (EC) in dS/m count Soil salinity saturated paste equivalent from 1:2 soil:water
31. median: 6.7 min: 0, max: 26 98 percent below 0 5 10 15 20 25 0 10 20 Nitrate + ammonium in ppm count Available nitrogen
32. Micronutrient median values • Iron: 198 ppm • Manganese: 27 ppm • Zinc: 6 ppm • Copper: 3 ppm • Boron: 0.4 ppm
33. www.asianturfgrass.com