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The (New) Fundamentals of Turfgrass Nutrition

C62291821dac0dd5b7ef3b72a30cd137?s=47 Micah Woods
January 13, 2016

The (New) Fundamentals of Turfgrass Nutrition

Most seminars, presentations, articles, and even semester-long courses about turfgrass nutrition discuss the functions of different elements. Potassium is involved in stomatal regulation, phosphorus is essential for root development, calcium for cell wall strength, and so on. All true, but largely irrelevant for the turfgrass manager. What the turfgrass manager must know is not the function of each element, but the quantities -- is enough of this element present to meet the grass requirements, or is it not? If it isn't present in adequate quantities, how much must be added to ensure the grass has enough? In this seminar, the fundamentals of turfgrass nutrition will be explained, with a focus on an understanding of the amount of each nutrient that is required.

C62291821dac0dd5b7ef3b72a30cd137?s=128

Micah Woods

January 13, 2016
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Transcript

  1. The (New) Fundamentals of Turfgrass Nutrition Micah Woods Chief Scientist

    Asian Turfgrass Center www.asianturfgrass.com 13 January 2016 Northern Green Expo Minneapolis, Minnesota
  2. What a ects growth? Growth is a function of photosynthetic

    light, plant water status, temperature, and a nutrient index.1 This can be represented as the environmental productivity index (EPI). 1Each of these factors can be represented by an index that takes a value from 0 to 1. Thus, the EPI will also have a value in the range of 0 to 1. The nutrient index is primarily a function of leaf N content.
  3. What a ects growth? Growth is a function of photosynthetic

    light, plant water status, temperature, and a nutrient index.1 This can be represented as the environmental productivity index (EPI). (light)(water)(temperature)(nutrient) = EPI 1Each of these factors can be represented by an index that takes a value from 0 to 1. Thus, the EPI will also have a value in the range of 0 to 1. The nutrient index is primarily a function of leaf N content.
  4. Light, Samui Island, Thailand

  5. Light, Samui Island, Thailand

  6. Light, Fukuoka, Japan

  7. antum light meter

  8. Water, Thailand

  9. Temperature, Iceland

  10. Nutrient – progressive K deficiency

  11. Growth = nutrient use

  12. Simplified EPI   XXX X (light)   XXX

    X (water)(temperature)(nutrient) = EPI
  13. Law of the minimum? “In terms of Liebig’s Law of

    the Minimum, nitrogen is usually the element in shortest supply, and therefore applying nitrogenous fertilizers has a large impact on plant growth. The reason that nitrogen, of all the elements, is so o en limiting to growth is simply that plants require a great deal of it.” Jonathan Silvertown in Demons in Eden: The Paradox of Plant Diversity.
  14. Not like this

  15. What is important soil pH

  16. What is important soil pH soil organic ma er content

  17. What is important soil pH soil organic ma er content

    N application rate
  18. What is important soil pH soil organic ma er content

    N application rate K in the soil
  19. What is important soil pH soil organic ma er content

    N application rate K in the soil P in the soil
  20. pH “In many parts of the world notably the US

    Midwest and Europe, soils have been limed to a particular target pH [6.5 to 7.0] according to the crop. Because plants do not directly respond to the activity of H+, it is pertinent to enquire why this approach to liming has enjoyed such widespread popularity ... Liming experiments throughout the world reveal that, with very few exceptions, all crops including legumes cease to respond to lime above pH [5.5 to 5.8]” Sumner and Yamada in Farming with Acidity, Communications in Soil Science and Plant Analysis, 2002.
  21. None
  22. None
  23. pH, GSS summary 4.5 5.0 5.5 6.0 6.5 7.0 7.5

    8.0 8.5 pH
  24. OM%, GSS summary 0.0 2.5 5.0 7.5 10.0 OM360

  25. K ppm, GSS summary 0 50 100 150 200 250

    KM3
  26. P ppm, GSS summary 0 100 200 300 400 PM3

  27. What is important soil pH, know it, normal conditions are

    pH in the range of 5.5 to 8.3
  28. What is important soil pH, know it, normal conditions are

    pH in the range of 5.5 to 8.3 soil organic ma er content, I like to know it
  29. What is important soil pH, know it, normal conditions are

    pH in the range of 5.5 to 8.3 soil organic ma er content, I like to know it N application rate, know it, and adjust it to achieve the desired growth rate
  30. What is important soil pH, know it, normal conditions are

    pH in the range of 5.5 to 8.3 soil organic ma er content, I like to know it N application rate, know it, and adjust it to achieve the desired growth rate K in the soil, keep above the MLSN guideline
  31. What is important soil pH, know it, normal conditions are

    pH in the range of 5.5 to 8.3 soil organic ma er content, I like to know it N application rate, know it, and adjust it to achieve the desired growth rate K in the soil, keep above the MLSN guideline P in the soil, keep above the MLSN guideline
  32. Two questions 1. Is this element required as fertilizer? 2.

    If it is required, how much should I apply?