Using the MLSN method for turfgrass nutrient requirements

I taught about MLSN using these slides in a presentation at the Czech Greenkeepers Association conference in Lednice. The presentation started with an explanation of how to use MLSN. I then explained why such an approach is necessary, and I closed with a quick explanation of how these guidelines were developed.

Transcript

1. Using the MLSN method for turfgrass nutrient requirements Micah Woods 12 December 2018 Chief Scientist Asian Turfgrass Center www.asianturfgrass.com
2. Nutrient deficiencies are avoidable disasters.
3. MLSN is designed to prevent nutrient deficiencies based on an analysis of the nutrients in the soil and the expected grass use of nutrients.
4. MLSN1 is a method for soil test interpretation. 1An initialism for minimum levels for sustainable nutrition.
5. Using MLSN
6. Let’s make sure we have enough beer
7. More specifically... One can express the quantity of an element required as fertilizer as Q. a + b − c = Q where, a is the quantity of the element used by the grass b is the quantity of the element kept in the soil c is the quantity of the element present in the soil Q is the quantity of the element required as fertilizer
8. a, site-specific estimate of plant use
9. Growth = nutrient use
10. 3 ways to get a number for growth 1. Estimate from clippings.
11. 3 ways to get a number for growth 1. Estimate from clippings. 2. Estimate from N applied.
12. 3 ways to get a number for growth 1. Estimate from clippings. 2. Estimate from N applied. 3. Estimate from temperature.
13. b, the quantity of element kept in the soil
14. c, the soil test result
15. MLSN newsletter: www.subscribepage.com/mlsn ATC newsletter: www.subscribepage.com/atcupdate
16. Why an approach like MLSN is necessary
17. Objective of turfgrass fertiliser applications Ensure the turf is supplied with just what it requires, while at the same time avoiding (or minimizing) overapplication.
19. 47 years ago …
20. “Fertilizer is the number one management tool. It is worth all the attention you can give it.” Madison, 19712 2Madison, J.H. 1971. Principles of turfgrass culture. New York: Van Nostrand Reinhold Co. p. 270
21. 40 years ago …
22. “A study was conducted to determine differences among soil testing laboratories … in fertilizer recommendations for turfgrass maintenance and establishment.” Turner & Waddington, 19783 3Turner, T.R. and D.V. Waddington. 1978. Survery of soil testing programs for turfgrasses. Comm. Soil Sci. Plant Anal. 9(1):71-87.
23. “Unfortunately, turfgrass recommendations appear to be based on research done with other crops, such as forages, results from turfgrass fertility studies not designed to relate to soil testing, and the best judgement of the agronomist making the recommendations.” Turner & Waddington, 1978
24. Seventeen years ago …
25. “In some cases, turfgrasses have been placed in a ‘high’ P and K requirement category … This decision was based on economics, not agronomics. The cost of fertilization was not considered of primary importance for turf.” Carrow et al., 20014 4Carrow, R.N., Waddington, D.V., and P.E. Rieke. 2001. Turfgrass Soil Fertility and Chemical Problems. Wiley. p. 164.
26. Five years ago … Surely these issues have been resolved?
27. “Calibration of … soil P with turfgrass growth and subsequent P fertilization recommendations is scant, and additional data is needed. Many current recommendations for P fertilizer for turfgrasses are based on forage- or field-crop calibration data.” Frank & Guertal, 20135 5Frank, K.W. and E.A. Guertal. 2013. Potassium and phosphorus research in turfgrass. In: Stier, J.C., B.P. Horgan, and S.A. Bonos, editors, Turfgrass: Biology, Use, and Management, Agron. Monogr. 56. ASA, CSSA, SSSA, Madison, WI. p. 493-519.
28. “Relationships between extracted soil K, K fertilization rates, and turfgrass response needs additional study. Such work is especially missing for the sand-based systems in which many turfgrasses are managed.” Frank & Guertal, 2013
29. Festuca, Iceland
30. Zoysia, Italy
31. Agrostis, Cynodon, and Festuca, Portugal
32. Poa annua, France
33. Reality: Conventional soil test calibration will never be done for even a fraction of the turf species, soil, and climate combinations.
34. Poa pratensis, Japan
35. Paspalum vaginatum, Thailand
36. Axonopus compressus, Indonesia
37. Digitaria didactyla, Sri Lanka
38. Two recent solutions 1. Fertiliser recommendations without soil test data.
39. Two recent solutions 1. Fertiliser recommendations without soil test data. 2. Fertiliser recommendations with soil test data.
40. Fertiliser recommendations without soil test data
41. In this case, it makes sense to apply—at least initially—all that the plant can use.
42. This is the STERF “Precision fertilisation” approach.6 6Ericsson, T., K. Blombäck and A. Kvalbein. 2013. Precision fertilisation—from theory to practice. STERF.
43. “Precision fertilisation is based on the assumption that during vegetative growth …, grass requires nutrients in constant relative proportions.” Ericsson et al., 2013
44. “By matching fertilisation to requirements during the season, it is possible to avoid undesirable fluctuations in grass growth and playing quality.” Ericsson et al. 2013
45. Fertiliser recommendations with soil test data
46. In this case, one wants to ensure the grass is supplied with all that it can use. If the soil can supply some—or all—of that amount, then the fertiliser recommendation accounts for the soil supply.
47. How we developed MLSN
48. Minimum levels for sustainable nutrition (MLSN) • Joint project7 of ATC (me) & PACE Turf (Wendy Gelernter and Larry Stowell, California) • Started with 16,163 soil samples collected from good-performing turf • Selected a subset of 3,683 with: • pH ≥ 5.5 & ≤ 8.5 • CECsum ≤ 60 mmolc kg-1 7Woods M.S., L.J. Stowell, and W.D. Gelernter. 2016. Minimum soil nutrient guidelines for turfgrass developed from Mehlich 3 soil test results. PeerJ Preprints 4:e2144v1 https://doi.org/10.7287/peerj.preprints.2144v1
53. 3 common questions 1. MLSN is a target level, or minimum level?
54. 3 common questions 1. MLSN is a target level, or minimum level? 2. Same minimum for every grass, soil, and location? Customization?
55. 3 common questions 1. MLSN is a target level, or minimum level? 2. Same minimum for every grass, soil, and location? Customization? 3. How do I know the nutrients are available?
56. For more, please see www.asianturfgrass.com.