Soil Test - Help??

Discussion in 'Organic Lawn Care' started by Barefoot James, Feb 9, 2011.

  1. Barefoot James

    Barefoot James LawnSite Senior Member
    Messages: 984

    I have a client who supplied me with a soil test done for their lawn (fescue grass and lots of sand burrs - full sun).

    The property is 2.5 acres and very sandy (notice that with the Ca/Mg ratio thats about 12:1) The sand burrs are a indication the soil has vertually ZERO nutrional value so these P and K #'s are from fert sitting in the soil (I would think) But P looks low to OK in Lawn. K looks OK? CEC is low in lawn and OM is not tested but he said before it was less than 1% which sucks.

    C.E.C 11.7
    soil pH 7.3
    Lime Index70
    P lbs/ac 185
    K lbs/ac 150
    Ca Lbs/ac4060
    Mg lbs/ac324
    Ca sat'n 87%
    Mg sat'n 11%
    K sat'n 2%
    Base sat'n100%
    Ca/Mg 7.5
    Mg/K 7

    No N#'s weird?

    I'm going to innoculate seed with mycorrhizae - seed at 6# per 1000 sq ft cover with compost (1 yard per 2500 sq ft) and 10# humus per 1000 sq ft
    regardless of any other inputs it might also need. If it is all sand it for sure need some priming of the pump and seed to get it moving.
    Last edited: Feb 9, 2011
  2. JoJo1990

    JoJo1990 LawnSite Member
    Messages: 244

    N is too mobile in the soil and that is why most reputable testing labs won't even provide a number. By the time they got the report to you it would have changed significantly already.
  3. ICT Bill

    ICT Bill LawnSite Platinum Member
    Messages: 4,115

    I think you will have nice results, you may or want to do the same thing in the fall, if we have a hot summer it may smoke some of your seedlings especially if it sandy, it will be hard to keep them from drying out

    I am on another forum that is mostly Ag related and we were having a discussion on how much compost to put down to be effective, in the end 1/32 of an inch had great results in soils that were low in SOM but little difference in soils that were relatively high in SOM
  4. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    CEC indicates you are probably dealing with a sandy loam or close to that, especially if the soil is low in organic matter. Some more OM would not hurt.

    With respect to turf

    P is high
    K is low
    Ca is high
    Mg is high

    Ca:Mg is acceptable

    While this may be true when attempting to assess different inorganic fractions of soil N, it is generally not true for total N. You can get your soil lab tested for inorganic N, but it requires special handling. If you need know your nitrates (the most common measured form of inorganic N) it would be better to field test rather than send a sample off. Most reputable labs offer all forms of N testing, they just may not offer it in their "standard" soil testing package. IMO, knowing your soils total N is critical knowledge for any organic program.
  5. Barefoot James

    Barefoot James LawnSite Senior Member
    Messages: 984

    Is there a chart or link that shows the acceptance ranges for N, P, K, Ca, Mg. these are typically pounds per acre right?
    Also Ca:Mg ratios - indicate compaction levels 7:1 and higher is good? Is there a good chart for this too for turf grass.

    Would NO3N be organic N?
  6. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,814

    I think your soil is adequate. Sure you need some slow-release or organic nitrogen, plus a steady diet of potash. Try to find a fertilizer that is at least 50 percent organic slow release nitrogen--70 percent is better, (plus some potash). Water is going to be your limiting factor. If you can apply your nutrients just before rain or during a rainy period, it will work nicely. I have heard that sandbur is not competitive with thick grass--I hope that is true. Wait for predicted rain and sock it on all summer. Plan to feed again in fall and again in late fall to build thickness.
  7. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    There is very general chart for turf that can be used as a rough guide, but it is not in lbs/acre, it needs to be converted.

    No chart, just numbers on generally acceptable % base saturation, and it can vary. The numbers you posted are acceptable for the pH reported.

    It would be NO3-N and you read that as nitrogen expressed as (or measured as) nitrate.

    An example of organic N is that which is tied up in organic matter compounds, like an amino sugar. It needs to be mineralized before it can become plant available.
  8. Barefoot James

    Barefoot James LawnSite Senior Member
    Messages: 984

    Thanks for the chart Kiril - easy to understand conversion chart - great information and details. I will for sure be able to use this a lot! Wish the calculator was live but at least the formulas are there.
    Thanks again for your help!
  9. ICT Bill

    ICT Bill LawnSite Platinum Member
    Messages: 4,115

    there's an app for that

    just not yet but I'll bet someone is working on it

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