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tlteel

Soil Test recommendations please help

10 years ago

I just received my soil test results and are as follows

Organic Matter 3.0

Phosphorous (weak bray) 67 very high (strong bray) 105 very high

Potassium 290 very high

Magnesium 280 high

Calcium 3197 medium

Ph 5.9

Buffer Index 6.6

Cation Exchange 23

Nitrate 27 high

Percent Base Saturation

potassium 3.2

Mg 10.0

Ca 69.5

Hydrogen 17.0

recommendations of dolomite 150 unsure of rate and .5 pound of Nitrogen/1000sqft Now

nitrogen .75 pounds/1000sqft and 0.5 pounds of K/1000 sq ft every 45 days

This is for common bermuda grass in central Oklahoma so far this year i have placed 34-0-0 in mid April at 1#/1000sqft and 32-0-10 at 1#/1000sqft mid May

I core aerated in april and verticut in may.

Comments (12)

  • 10 years ago

    The C.E.C is 23 I don't see a listing for T.E.C

  • 10 years ago

    That's not exactly what I call shabby! I wish my first read had looked like that.

    Pursuant to an ongoing discussion/argument, I'm giving you the BCSR reading, and I'm giving you one that's designed to park your soil in the perfect groove so that it takes longer to drift to unacceptable. I also recommend adjustments to minor elements that are far less important (to relatively unimportant) but do subtly impact grass/plant quality, so allowing them to fall too low is not the best idea.

    Let's start.

    CEC 23: A pretty heavy soil, very silty, possibly with some clay. It's not a problem, and it holds lots of resources. When wrong, it takes more resources to correct, but when right, it won't drift quickly. Once balanced--yours pretty much already is--testing every second to third year is more than sufficient.

    Organic Matter 3.0: In the Fair range. Given your high CEC, certainly mulch mow, mow in all your fall leaves, and you can feed organically if you want to, but no special effort needs to be made here.

    pH 5.9: Always a symptom, never the disease, and yours isn't that far off optimal levels (your optimal at a CEC that high will balance below what others will. In my own higher-CEC soil, my optimal pH is 6.2). I also have a suspicion that the pH is reading a little low and is actually a tad higher--something that happens about 5% of the time due simply to testing result variance.

    Nitrate 27: You probably fed the lawn recently, or just mulch mowed, or something like that. I ignore all nitrogen readings as relatively unimportant. They vary by user action, temperature, time of day, moisture levels, and so on. While nitrate has implications for how effective your soil biology is (which flips nitrogen from ammonia to nitrate forms), it's not a particularly useful number without knowing the ammonia result.

    Phosphorus, Weak Bray, 67: Quite high, but certainly not a problem. The weak Bray test target is around 25 for most grasses, Bermuda not being an exception to that rule. The weak Bray test measures readily available phosphorus that the plant can access. Certainly you don't require any phosphorus and don't really want to add any.

    Phosphorus, Strong Bray, 105: Again, quite high but not an issue at all. The strong Bray test measures both readily available P and the easier to access P in the soil reserve (that will eventually weather and become available). The target here would be around 50 for most grasses (including Bermuda).

    Calcium 69.5%: Technically optimal (target in a soil of your CEC would be around 65-70%). Your pH is reading low, but I don't want to kick this very much. I've recommended a very minimal amount of calcitic limestone below, but it's strictly optional. For this, we use Encap, Mag-I-Cal, or Pennington Fast Lime as other limes are a little too slow.

    Magnesium 10.0%: In a soil with your CEC, this is more than adequate...even if textbook a bit low. I'd like to kick it a hair, but we'll do so the cheap, slow way. Again, this is optional--and we use the cheap dolomitic limestone to do so, the $5 per 40 pounds lime you see in stores marked "dolomitic." Get pelletized, it's easier to handle.

    Potassium 3.2%: While I don't mind seeing 4% or even more, this is more than adequate and no adjustment is required.

    Minor Elements: Not Tested.

    Recommendations:

    June 1: (Optional) Apply 3 pounds per thousand square feet of calcitic lime. (Optional) Apply 10 pounds per thousand square feet dolomitic limetone.


  • 10 years ago

    There's a question hovering on my mind that I'm sure is going to occur to you: why am I recommending 12 pounds of limestone when the test recommends 150?

    Simply put, I don't believe that pH result, and that happens more than you'd think. I actually think your pH is closer to 6.0 or 6.1, which is coming into proper range, particularly on a heavier soil. The reason being is that your calcium levels are great and, even if a bit lower than I might like to see overall when calcium is at the upper end, magnesium is nothing shabby.

    If it turns out I'm wrong, no harm done, we'd simply kick the pH with the next soil test. If right, we avoided sending your calcium or magnesium saturation too high and potentially causing problems. So here, as usual, I erred on the side of not doing any potential damage for a result I'm not sure about.


  • 10 years ago

    Thanks! I appreciate the Profesional advice. Should I continue my monthly nitrogen schedule? 34 0 0 @ half rate every two weeks or a slow release monthly? I'm also going to replace my blades with mulching blades. I also plan on using essentials 1 0 1 humid acid

  • 10 years ago

    Yep, keep up with the nitrogen, it has no impact on what's going on here.

    I can argue humic acid either way, but use for a year or so initially won't hurt. In your case, you don't really require it (your CEC is already very high and there's no indication of biological issues), but it sure won't hurt.

  • 10 years ago

    This maybe a stupid question but when applying lime, do you actually apply 3 pounds of product or do I need to calculate the amount by percentage

  • 10 years ago

    I guess some things are to good to be true. The soil test I posted was incorrect the seed company had sent me the wrong test. Unfortunately my test is much worse. I will post here and maybe I can get another recommendation

    Organic matter 3.1

    Weak bray P 69 very high

    Strong bray P 75 very high

    K 248 very high

    Mg 163 medium

    CA 988

    Na 35

    PH 5.1

    Buffer index 6.5

    CEC 11.4

    Percent base saturation

    K 5.6

    Mg 11.8

    CA 43.3

    H 38

    Na 1.3

    Nit rate 47 very high

    Sulphur 10

    Zinc 3.7

    Nanganese 3.7 high

    Iron 85 very high

    Copper 0.5

    Boron 0.3 very low

    Once again I apologize


  • 10 years ago

    Yes, that is going to make a difference. He's going to be making some changes and I'd bet you have lost your "option" :) Don't buy anything until he reviews it.

  • 10 years ago

    Hopefully he will stop back by this thread

  • 10 years ago

    You got it. Those recommendations and the read above, throw them out. They no longer apply. I hereby officially chastise your seed company and spank them with a wet trout.

    CEC 11.4: A silt-sand soil, and again, not a bad place to be. It'll drift much faster than the originally-reported-on soil, but still, testing every 2 years once it's balanced will be more than sufficient.

    OM 3.1%: Still in the Fair range, so the recommendations above apply. Mulch mow, mow your leaves, but there's no reason to go crazy about it.

    pH 5.1: Lower than the previous read and not so great, but we can work with this. I'll correct it under calcium, magnesium, and potassium where it needs correction.

    Sulfur 10: Exactly in optimal range, with tons of room to play with (we actually don't need any of this margin).

    Weak/Strong Bray 69, 75: Both sufficient (goals would be 25 and 50 or so, respectively). This test shows an interesting tendency for your soil P to be in available form over short-term bound form. That's not an issue, it's just interesting, and it'll change a bit as we alter the pH--by intensifying slightly. It implies a very good level of biological activity. Regardless, no phosphorus is required or desired, but you don't have to specifically avoid smaller phosphorus sources, either.

    Calcium 43.3%: Quite low, and what's setting off your pH problem. Target here is 60-70%. In a CEC 11 soil, my target is 65, but I really wouldn't be terribly worked up by anything within the target range. To correct this faster, we use calcitic lime to avoid adding magnesium (and also, again, the speed of correction). I recommend Encap, Mag-I-Cal, or Pennington Fast Lime.

    Magnesium 11.8%: Optimal for your CEC. There's no reason to raise this and I'm not inclined to do so, but you also don't have to avoid smaller sources of magnesium.

    Potassium 5.4%: While textbook, this is very high, I actually like to be in this range in many soils. Potassium enhances disease and temperature resistance, and gets used in tons of enzymes. None is required or desired but again, you don't have to avoid minor sources of potassium.

    Minor Elements: Most are fine, even if they say iron is very high (that doesn't matter, iron isn't toxic until absolutely ridiculous levels at a reasonable pH, which is where we're sending you). I'm not directly familiar with the test used or the quality of the testing in terms of boron. So although it reads low, I'm not inclined to fiddle with it at this time.

    Recommendations:

    June 1: Apply 8 pounds of calcitic lime per thousand square feet.

    October 1: Apply 8 pounds of calcitic lime per thousand square feet.


    tlteel thanked User
  • 10 years ago

    You need lime. Dolomitic react more rapidly than calcitic, but you don't need the Mg, so calcitic is preferable. Bring the pH up to 6.5. You can put it on all at once or split it into several applications. As long as you don't smother the grass, it won't hurt a thing.

    And manage nitrogen!