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Using the MLSN method for turfgrass nutrient re...

Micah Woods
December 12, 2018

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.

Micah Woods

December 12, 2018
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  1. Using the MLSN method for turfgrass nutrient requirements Micah Woods

    12 December 2018 Chief Scientist Asian Turfgrass Center www.asianturfgrass.com
  2. MLSN is designed to prevent nutrient deficiencies based on an

    analysis of the nutrients in the soil and the expected grass use of nutrients.
  3. MLSN1 is a method for soil test interpretation. 1An initialism

    for minimum levels for sustainable nutrition.
  4. 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
  5. 3 ways to get a number for growth 1. Estimate

    from clippings. 2. Estimate from N applied.
  6. 3 ways to get a number for growth 1. Estimate

    from clippings. 2. Estimate from N applied. 3. Estimate from temperature.
  7. Objective of turfgrass fertiliser applications Ensure the turf is supplied

    with just what it requires, while at the same time avoiding (or minimizing) overapplication.
  8. “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
  9. “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.
  10. “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
  11. “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.
  12. “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.
  13. “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
  14. Reality: Conventional soil test calibration will never be done for

    even a fraction of the turf species, soil, and climate combinations.
  15. Two recent solutions 1. Fertiliser recommendations without soil test data.

    2. Fertiliser recommendations with soil test data.
  16. This is the STERF “Precision fertilisation” approach.6 6Ericsson, T., K.

    Blombäck and A. Kvalbein. 2013. Precision fertilisation—from theory to practice. STERF.
  17. “Precision fertilisation is based on the assumption that during vegetative

    growth …, grass requires nutrients in constant relative proportions.” Ericsson et al., 2013
  18. “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
  19. 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.
  20. 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
  21. 3 common questions 1. MLSN is a target level, or

    minimum level? 2. Same minimum for every grass, soil, and location? Customization?
  22. 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?