Fertilizer's Affect on Trees

Discussion in 'Fertilizer Application' started by Coffeecraver, Dec 5, 2004.

  1. Coffeecraver

    Coffeecraver LawnSite Senior Member
    from VA.
    Posts: 793

    Fertilizer's Affect on Trees
    By Paul Martin, Growing Earth Tree Care
    Editing by Bonnie Appleton, VA Tech


    Believe it or not, fertilizers are do not directly provide food for trees. Trees produce their own food (sugars, carbohydrates and starches) in their leaves, through the process of photosynthesis. Fertilizers provide the source of the nutrients required for photosynthesis. Not all trees require fertilizer, but all trees require the nutrients available in fertilizers. In the forest, many of these nutrients are recycled as the leaves fall and decay back into the soil.

    Sunlight is converted into chemical energy by the choloroplasts in the leaves. The elements in fertilizers are necessary to maintain chloroplasts. They are necessary in the production of many other compounds, including enzymes, nucleic acids, proteins and alkaloids. Cell walls and membranes also require these elements.

    The three main elements of complete fertilizers -nitrogen, phosphorus and potassium -are essential for plant growth. These substances are listed on the packaging by their percentage of weight, such as 30-10-10. The first number is nitrogen, the second is phosphorus and the third is potassium. It's easy to remember the order because they're listed alphabetically. Many of the fertilizers available commercially contain small amounts of trace minerals including iron, manganese and zinc, but the small quantities are usually insufficient to correct a deficiency.

    The three main nutrients are usually present in the soil, in limited quantities. Lack of a proper amount in the soil can stunt a tree's growth. Nitrates, the major source of nitrogen, are soluble in water and can be easily leached by drainage water. Organic fertilizer is continually producing nitrogen as micro organisms break down the organic matter.

    Discolored leaves can signal a deficiency of certain nutrients, such as nitrogen. Too much nitrogen, though, can attract nitrogen feeding insects or produce sucker growth. Before you apply any fertilizer, have the soil analyzed, then apply the correct formula and rate.
     
  2. Ric

    Ric LawnSite Fanatic
    Posts: 11,957

    Coffee

    What is the relationship between Trees and Turf as far as Water and Nitrogen. Now Trees steal light from turf. So does turf take either water or Nitrogen from the tree or do trees take it all??? Sure this is a question I know the answer too. However it will help make your original point.
     
  3. Coffeecraver

    Coffeecraver LawnSite Senior Member
    from VA.
    Posts: 793

    Since trees get their nutrients from the top 6 inches of soil ,when you cover them up with turf the turf will steal from the tree.

    Now if you plant a black walnut,the toxins from the tree will steal from the turf.

    Trees and turf are not the best of friends.

    :)
     
  4. Ric

    Ric LawnSite Fanatic
    Posts: 11,957


    correct sir on the nutrients. However black walnuts puts out a antagonistic toxin that kills grass and other plants. In fact If you were to put smashed walnuts in a pond they would kill the fish.

    Now, what about water???
     
  5. Coffeecraver

    Coffeecraver LawnSite Senior Member
    from VA.
    Posts: 793

  6. trying 2b organic

    trying 2b organic LawnSite Senior Member
    Posts: 566

    Coffee, given your post, do you recommend and sell mulch circles around trees, particularly fruit trees, for your customers? Does it make a noticable difference in the health of the tree? Will they actually save money in the long run by needing less insecticides and fungicides cause a healthy tree is less prone to problems?

    Ill guess that turf robs trees of water. That seems logical. Heres a tougher one for you. Do the herbicides, insecticides and fungicides we apply to turf under trees affect the trees in any way? :help:
     
  7. AintNoFun

    AintNoFun LawnSite Bronze Member
    Posts: 1,807

    so sucker growth is related to much nitrogen?
     
  8. Ric

    Ric LawnSite Fanatic
    Posts: 11,957


    Trying

    Most Fruit Trees and Particularly Citrus have many hair roots near the surface. They like lots of water but don't like wet feet. Good drainage is an important factor with just about every plant but Particularly Fruit trees. Mulch inhibits air exchange with the soil. Therefore because of most Fruit trees demand good aeration, mulch is not recommended. Most orchards will in fact have bare ground under the trees and maintain it with Roundup.

    Turf Robs trees of N-P-K etc. but Trees Robs Turf of Water.

    Now for the "Tough one" you ask. Yes systemic pesticides can and are up taken by the tree roots. And, remember their roots will extend out passed the drip line and into the turf. Visible damage is offended seen from Broad Leaf Herbicides since trees are broad leafs. In fact every time I see a tree in decline, Herbicides is my first question. Systemic Insecticides and Fungicides are also up taken. Because you see no physical signs of their effect they can be dangerous to those who eat the fruit. Now an application of Merit to the Lawn for Grub control, may control sucking insects on the tree and cause it to express itself to the fullest. However it might not be the safest fruit to eat.
     
  9. Ric

    Ric LawnSite Fanatic
    Posts: 11,957


    Aint

    Sucker Growth or Water Sprouts are a sign of a trees in stress. That stress can be from a multitude of reasons.
     

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