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MLSN: just what the grass requires AND Soils that produce the best grass today

C62291821dac0dd5b7ef3b72a30cd137?s=47 Micah Woods
February 15, 2018

MLSN: just what the grass requires AND Soils that produce the best grass today

My presentation slides about MLSN and the Global Soil Survey at the WCTA conference.

C62291821dac0dd5b7ef3b72a30cd137?s=128

Micah Woods

February 15, 2018
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Transcript

  1. MLSN: just what the grass requires and Soils that produce

    the best turf today Micah Woods February 15, 2018 Chief Scientist Asian Turfgrass Center www.asianturfgrass.com
  2. Today’s schedule 13:30 – 15:00: all about MLSN

  3. “Fertilizer is the number one management tool. It is worth

    all the attention you can give it.” John Madison, Principles of Turfgrass Culture (1971), p. 270
  4. MLSN1 is a method for soil test interpretation. 1An initialism

    for minimum levels for sustainable nutrition.
  5. MLSN is designed to prevent nutrient deficiencies based on an

    analysis of the nutrients in the soil and the expected grass use of nutrients.
  6. MLSN newsletter: www.subscribepage.com/mlsn ATC newsletter: www.subscribepage.com/atcupdate

  7. The key concepts

  8. Nutrient deficiencies are avoidable disasters.

  9. The two possible extremes 1. Supply nothing and assume the

    soil can provide all the grass requires. 2. Supply 100% (or more) of the nutrients the grass can use.2 2This approach makes the implicit assumption that the soil cannot supply the nutrients.
  10. “How many more times do I have to say that

    applying nutrients to turfgrass growing on soil already well supplied with the nutrients is a waste of time and money?” Wayne Kussow in “Manipulating Creeping Bentgrass Nutrition” (1995)
  11. Two questions 1. Is this element required as fertilizer? 2.

    If it is required, how much should I apply? To answer those questions, we need to know how much is used by the grass and how much can be supplied by the soil.
  12. T o a n s w e r t h

    o s e f u n d a me n t a l q u e s t i o n s , w e n e e d t o e s t i ma t e 3 q u a n t i t i e s c r e e p i n g b e n t g r a s s S h a n g h a i , C h i n a
  13. MLSN is a method for soil test interpretation

  14. a, b, and c • a is a site-specific estimate

    of plant use. • b is the amount we want to ensure remains in the soil after the plant use is accounted for. This is a minimum we don’t want to drop below. You can think of it as a reserve amount in the soil. This is the MLSN guideline level. • c is the amount actually present in the soil. This is the soil test result.
  15. a, site-specific estimate of plant use

  16. Growth = nutrient use

  17. 3 ways to get a number for growth 1. Estimate

    from clippings.
  18. 3 ways to get a number for growth 1. Estimate

    from clippings. 2. Estimate from N applied.
  19. 3 ways to get a number for growth 1. Estimate

    from clippings. 2. Estimate from N applied. 3. Estimate from temperature.
  20. b, amount to ensure remains in the soil

  21. 1. The conventional way – low, medium, & high classification

  22. 1. The conventional way – low, medium, & high classification

    2. Conventional guidelines are broken
  23. 1. The conventional way – low, medium, & high classification

    2. Conventional guidelines are broken 3. The MLSN guidelines address these problems
  24. The conventional way – low, medium, & high classification

  25. The conventional way GCSAA GCM Magazine, January 2004

  26. List of ranges • low • medium • high

  27. “Low range: a high probability (80-100%) that applying the nutrient

    will elicit a growth response.”
  28. “Medium range: approximately a 50% chance of getting a plant

    growth response …; if supplemental fertilizer is not applied, growth will probably be limited, especially as the season progresses.”
  29. “High range: little or no crop response is expected from

    applying the particular nutrient.”
  30. Conventional guidelines are broken

  31. “In some cases, turfgrasses have been placed in a ‘high’

    P and K requirement category, while pasture grasses were in a ‘low’ category. This decision was based on economics, not agronomics. The cost of fertilization was not considered of primary importance for turf.” Carrow, Waddington, and Rieke in Turfgrass Soil Fertility and Chemical Problems (2001), p. 164
  32. And grass is often grown in sand

  33. “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 in “Survey of soil testing programs for turfgrasses” (1978)
  34. Soils that produce the best turf today

  35. None
  36. GSS kit, good performing turf

  37. GSS sample locations, 2013 to 2016

  38. Samples collected from good performing turf

  39. None
  40. None
  41. None
  42. None
  43. “Every time a researcher conducts one of these studies, they

    tend to find that the levels required are lower than what we previously thought – meaning that ‘low potassium’ you got on your last soil test report might be optimum down the road.” Doug Soldat in “How reliable is soil testing?” (2013)
  44. The MLSN guidelines address these problems

  45. “I recommend you compare your results with PACE Turf’s Minimum

    Levels for Sustainable Nutrition [MLSN] guidelines ... the minimum levels published by PACE are drastically lower than many traditional soil test interpretations, and likely more accurate.” Doug Soldat in “How reliable is soil testing?” (2013)
  46. The MLSN guidelines address these problems

  47. c, the amount actually in the soil

  48. Using MLSN

  49. Let’s make sure we have enough beer

  50. 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
  51. 3 common questions 1. MLSN is a target level, or

    minimum level?
  52. 3 common questions 1. MLSN is a target level, or

    minimum level? 2. Same minimum for every grass, soil, and location? Customization?
  53. 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?
  54. None
  55. For more, please see www.asianturfgrass.com or @asianturfgrass on Twitter.