NPK ratios

Discussion in 'Fertilizer Application' started by elliefert, Oct 11, 2013.

  1. elliefert

    elliefert LawnSite Member
    Messages: 9

    How many NPK ratios are available now on markets?

    If I wanna category them, is there a way to do so?
    As small, medium, large?

  2. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,808

    There are lots of ratios. And...if you include custom ratios that any country elevator can make up for you, there are hundreds. A lot depends on the starting material and the percent of inerts in the starting materials. I am sure there is a computer program to calculate the possible ratios somewhere, (given certain base materials).
    For instance I went to my supplier and asked for a special analysis ratio of 41-0-6.5...and eventually he agreed to make it and bag 4 tons for me.
    Of course, 46-0-0 is the maximum urea ratio possible--you cannot get to 47 or 50-0-0 with urea. Likewise you cannot exceed 62 in a potash mixture as 0-0-62 is the maximum possible using potassium chloride.

    For turf a high ratio of slow release is very important. However, opinions vary and some products are not suitable for certain grass types, soils or climates. There are regional laws, preferences and recommendations. Different seasonal ratios are often advised--and ratios exist to reduce disease or increase organic matter
  3. elliefert

    elliefert LawnSite Member
    Messages: 9

    make sense and interesting

    Do you know there would be maximum limits if it is liquid?

  4. jonthepain

    jonthepain LawnSite Senior Member
    Male, from Raleigh
    Messages: 595

    Posted via Mobile Device
  5. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    What you would want to know is how much product to put down to achieve 1 pound of actual N per thousand sq. ft. or perhaps .5 pounds of N/k... then know how much potassium you want per thousand and what the NPK percentages will give you what you want/need for a particular application...

    You may loose sight of the goal by overthinking the procedure ,,, backwards... :)
  6. foreplease

    foreplease LawnSite Silver Member
    Messages: 2,062

    I agree with axe, here, and would add: the rate of application you choose should be tailored to the N source and type of extended release, if any. Also, think in terms of season-long ratios and rates. If you are removing clippings, assume you are mining K out of your lawns and adjust accordingly - some say this can be as much as 1# K/M per year.

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