Just received my soil testing report. What now?

Discussion in 'Turf Renovation' started by speedster, Aug 16, 2010.

  1. speedster

    speedster LawnSite Member
    Posts: 190

    Not sure if this post belongs in Fertilizer or lawn renovation so I just put it here.

    I've got about 7000 sq/ft of yard space that's in pretty bad condition. The results from the soil test confirm this. I have mostly sunny areas with about 600-1000 ft' of mostly shady areas. Two large spruce trees contribute to my acid problem. Soil is pretty clay rich and not a whole lot of healthy grass. I have a lot of crabgrass and broadleafs that I sprayed a few weeks back with 2-4D with pretty decent results. Most of the crabgrass is brown and dead but most of the broadleaves still exist. The majority of what turf I have is KBB with some fine fescue in the shadier areas. I do also have some moss growing I believe due to the low pH. I cut the grass all summer long at a pretty high setting which kept it green. But before spraying a few weeks back I began a process of shortening my cuttings. I'm not scalping it but I am cutting pretty short in anticipation of overseeding soon. My original plan was to rent a slit seeder early september and dry run it a few times to dethatch and then seed heavily. I plan to topdress to some degree with top soil and compost. Then come spring I planned on aerating, and applying a pre-emergent to revent the crabgrass from coming back. By that time I hope my lawn is much thicker and can better defend itself against broadleaves and crabgrass.

    Anyway, I got the results back from the lab and they read as follows:

    pH = 4.8 !!!
    P = 33 lbs/acre MED
    K = 190 lbs/acre HIGH
    CA = 1490 lbs/acre MED
    MG = 153 lbs/acre MED

    Here are their recommendations:
    Aglime = 170lbs/1000 sqft !!! (~1200lbs for my lawn?)
    Nitrogen (N) = 3 lbs/1000 sqft
    Phosphate (P205) = 1 lbs/1000 sqft
    Potash (K20) = 0 lbs/1000 sqft

    You can use any fertilizer that supplies the plant nutrients recommended. Apply all of the P205 and K20 and approximately 2/3 of the N in the fall and the rest of the N in the spring after the flush of spring growth.

    AS you can tell the soil is in bad shape. With all of my ambitious plans what should I do now? Do I seriously need to put down 1170lbs of aglime all at once? Can I do this right now and then seed in 2-3 weeks? Will this in any way hamper seed germination?

    As you can probably guess the spruce trees might have something to do with the pH problem. This is my first summer in the house so I'm not sure what type of lawn maintainance the previous owner performed. Obviously he never added lime :)

    Whats my game plan fellas?
  2. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,081

    I think I would aerate, a couple directions , then add lime and compost, to get that stuff down into the clay. The slowly moves through the soil and is only a temporary fix. Compost,SOM, buffers the ill-effects of pH extremes and allows grass to grow inspite of it. If you got low SOM and CEC along with bad structure, you are setting yourself up for growing thatch, just to keep it alive.
  3. speedster

    speedster LawnSite Member
    Posts: 190

    thanx for the tips. what exactly is som and cec
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  4. speedster

    speedster LawnSite Member
    Posts: 190

    As far as the aglime is concerned, this is my first lawn and I've never actaully applied lime before.

    In my case what would be the best type to add to my lawn? The powdery stuff or the pellitized lime? Obviously I'd assume I'd apply it to a dry lawn. If I go with the powdery stuff does it get watered in? Will this effect the seeding I plan to do in early september?

    Also, since the report suggests that my K is high what type of fertilizer should I look for? Like a 30-5-0 or something like that?
  5. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,081

    SOM = Soil Organic Matter. Sand, clay and silt are inorganic.

    CEC = Cation Exchange Capacity. That means nothing more than the NPK has a place to sit, one particle at a time, until the plant can use it. Without a place to be much of the N goes unused, on bad soils, with no structure. It tends to grow, almost hydroponically, producing thatch.
    Clay, OM and silt are the common CE sites, in a soil.
  6. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308



    I would lean towards moving your lawn to all fescue as it can tolerate pH extremes far better than KBG can.

    With respect to the soil test ... it is not telling you much of anything. With the exception of the pH, the numbers are meaningless without knowing the depth of soil it applies to. That said, if we assume 6", then they are perfectly acceptable IMO, and need no adjustment.
  7. speedster

    speedster LawnSite Member
    Posts: 190

    when you say fescue are you talking about tall turf type? I've heard out can be really clumsy and lwots of maintainance to repair.
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  8. speedster

    speedster LawnSite Member
    Posts: 190

    Geeze, no way to edit posts here?

    Sorry I posted from my phone. What I meant to say was I've heard tall fescue can make you yard clumpy and uneven. I've also heard it can be a lot of maintainence to repair because it doesn't fill in.

    I stopped by my local co-op yesterday and bought 520 pounds of pellitized lime. Thats all they had. After seeing how little 520 pounds actually is of lime it doesn't sound so rediculous that my lawn needs 1170 pounds according to the report. I'll probably put this lime down and then add another 500 when they get more in stock.
  9. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    This is untrue.
  10. stealle

    stealle LawnSite Member
    Posts: 4

    I think that is way too much lime to add all at once. I would never apply more that 50lbs per 1000 at a time. Also, it is best not to apply lime and fertilizer at the same time. It works kinda like this. The ideal pH for grass is between 6.0-6.5. If pH is 7 or more the soil will hold iron and will not release it to grass and trees (less greening). A pH less than 6 becomes too acidic for most lawn grasses. Also, if the pH is too low the nitrogen in lawn fertilizer will not work as well, which means less growth and greening of your lawn. So you need lime so the fertilizer will work better. The catch is, you can't apply lime and fertilizer (nitrogen) at the same time or they basically cancel each other out. Meaning, if you apply them at the same time, your pH will not increase much and the nitrogen will not be usable to your grass. For best results apply lime at least one month preferably 3 months before applying nitrogen.

    If I were you I think I'd do this.
    1. Apply 50 lbs of lime per 1000 sq ft. now. Make sure it gets watered in really good several times before seeding.
    2. In a couple weeks, seed your lawn. Do light watering several times a day to keep the soil moist (not flooded).
    3. Apply a good starter fertilizer one month after the lime application. I usually apply starter fertilizer at the same time of seeding, but in your case I think the lime needs time to soak in first. By this time your seed is starting to germinate. The small seedlings will still appreciate the fertilizer. Try to get several mowings in before the first frost.
    4. Apply another 50lbs lime per 1000 sq ft. in November. Late fall is the best time too apply lime. It will gradually soak into the soil all winter long.
    5. Apply another 50lb lime per 1000 sq ft. in February 2011. That's enough lime! Have your soil tested again in the Fall of 2011
    6. Get on a regular fertilizer plan in the spring 2011. Plan to do some more over-seeding in the spring. You might have better luck since your soil should be much improved.

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