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immobilus

Tucson - nitrogen deficiency

immobilus
10 years ago

I did a lowe's soil test in my yard and found that I have a severe nitrogen deficiency. I suppose this would explain why my plants, e.g. Photinia and crape myrtles, have incredibly anemic growth. The leaves on the photinia are extremely small and they are not growing at all (the leaves also droop by noon).

I have ammonium sulfate which is 21-0-0. Will adding this to the soil resolve the nitrogen deficiency and fix the growth problem? Is it safe to add ammonium sulfate when the heat is above 100 degrees?

Thanks.

Comments (10)

  • nc_crn
    10 years ago

    Water it in immediately and well (not enough to leech it out of your soil, though) and you're good to go.

    It needs water to drive it into the soil, make the chemical reaction that acidifies your soil (good thing in alkaline soils common in the area), and to keep from losing all the good parts of the addition to the atmosphere.

    Avoid using excessive amounts on applications depending upon what you're trying to amend...it is highly water soluble and immediately available (as well as quickly acidic).

  • immobilus
    Original Author
    10 years ago

    I did it and think I over did it. The leaves and flowers are all falling off. Not sure how to fix. I think I do love them too much. How do I un ammonium the soil so the leaves start back?

  • immobilus
    Original Author
    10 years ago

    I did it and think I over did it. The leaves and flowers are all falling off. Not sure how to fix. I think I do love them too much. How do I un ammonium the soil so the leaves start back?

  • aztreelvr
    10 years ago

    Water deeply and slowly to leach excess fertilizer from the soil. Be sure to allow the soil to dry a bit before you water again. This allows oxygen to return to the soil which is critical for root metabolism.

  • aztreelvr
    10 years ago

    Water deeply and slowly to leach excess fertilizer from the soil. Be sure to allow the soil to dry a bit before you water again. This allows oxygen to return to the soil which is critical for root metabolism.

  • centurion_
    10 years ago

    Sorry to hear about this. I read your first post and was going to suggest coffee grounds. A lot of starbucks and other coffee shops will give them away for free. I get mine at our local minimart/gas station. I drop off a 5 gallon bucket and switch em out every few days.

    It's cheaper and more organic. Here's a link for next time:

    http://www.buzzle.com/articles/coffee-grounds-for-plants.html

  • nc_crn
    10 years ago

    Ammonium sulfate is extremely useful (especially for alkaline soils), but it is extremely "powerful" and immediately available.

    Over-doing it can be quite easy given how water soluble it is. It's something that can be applied in small amounts and more added later if needed. It's availability is so quick acting that you have some leeway with under-doing it and quickly taking care of the issue later with another application if needed.

    Overdoing it can lead to an immense amount of available N in the root zone as well as a temporary drastic pH change (the drastic pH change is usually temporary because the soil chemistry buffers itself back to a less extreme change).

    Like mentioned, flushing the root zone with water is the best way to take care of the issue.

  • immobilus
    Original Author
    10 years ago

    Yea, but I thought a lot of N would just cause the plant to grow like crazy. Not drop all its leaves. So like a low-trickle or massive flooding? I put about a cup down. Apparently it was way too much for a 3x3 area. It won't kill the roots will it? The cambium even on this year's new growth is still green.

  • Fascist_Nation
    10 years ago

    Man I can't stop laughing. You know another reason besides a ton of nitrogen for leaves dropping off? Overwatering.

    And what is the point of asking for advice if you just go ahead and do what you want before the advice comes in? And drop an atom bomb to boot.

    Not to mention the time to fertilize trees was about 6-8 weeks ago. In fairness, today I did add a bit of corn gluten to a couple of peach tree cultivars only a few months in the ground that surprised me this morning's walk through with obvious signs of nitrogen deficiency (I am wondering how much is heat related) right before flood irrigating starts in a few minutes.

    Here is a link that might be useful: {{gwi:406496}}

  • immobilus
    Original Author
    10 years ago

    It worked guys. I watered thoroughly every day for two to three weeks and the nitrogen levels are slightly elevated from the surrounding soil (what I wanted). The leaves are growing back on the bare branches. I stopped the ammonium sulfate applications (though a small amount may be useful in preparing the tree for spring with a small 10-10-10 or 5-5-5 dose of general fertilizer in late March-April.

    Anyway, they're coming back nicely. I put a sprinkling of blood meal on the soil to keep the nitrogen levels slightly elevated. Watered it good. Then put about 5 inches of mulch in the drip zone.

    They're already beginning to bloom again. The reason I was so adamant about nitrogen was because my soil is so incredibly low in it. Two years later and the trunk hasn't thickened at all. I find the nitrogen does encourage stronger limbs and a thicker trunk.

    Flowers will be welcome when the trees are able to stand without a stake (hopefully next year). I'm not going to prune this spring. I'll hold off until the following so the limbs can actually bear the weight of the flowers.

    Anyway thanks for the advice!

    Now if I could figure out how to fertilize my photinias without them dying and leaves getting torched by the sun!