Please help me interpret this soil test

Discussion in 'Pesticide & Herbicide Application' started by godjwood, Jul 15, 2009.

  1. godjwood

    godjwood LawnSite Member
    from RI
    Messages: 137

    Hey there guys-

    I used to blindly put down the fertilizer "four step" programs. But lately I have been trying to improve and take the guess work out of fertilizing.

    I went out and bout a CBRIII spreader since I thought it would be more accurate. I have also been getting soil tests for some of my nicer lawn accounts at my local seed store and they give me printouts like the ones below:


    However they are not very helpful there. So I was hoping you guys might be able to give me some insight.

    From this soil test shown above, they recommended i put down a 19-0-19 fertilizer.

    So i put down a 19-0-19 fertilizer, arbitrarily at a 3.5#/1000ft^2 since they didn't tell me a specific rate to put it down at.

    Now, how do I know if the levels are now corrected besides another soil test after every application? Is there no way to eliminate the guess work from fertilizing?

    From my interpretation, the 19-0-19 fertilizer (Nitrogen-Phosphorus-Potassium) has high nitrogen for growth, 0 Phosphorous which is good since the level is listed as "High" and high Potassium content which is good since it is listed as "Low" on the soil test results.

    Now I asked the owner of the seed store how you can decrease the sodium level since it is listed as an "increasing problem" and he told me I could put down gypsum. How much, I don't know.

    Lastly, the Calcium and Magnesium was listed as "low" in the soil test. I inquired about this, and his answer was to put down lime. However, when I brough up the fact that the PH was in the optimal range at 6.1, his answer was to put down very "light" applications of lime several times.

    I am really trying here and frustrated because everything seems so arbitrary. Is this just how things are with soil tests and lawns? Because i Know the seed store I go to really knows their stuff, I just wish I could get some precise figures here.

    Any input would be helpful. I have had many soil tests and this is just one example so I am looking for information that would help me in the long run and not just with this specific soil test.

    Thank you all so much.
  2. godjwood

    godjwood LawnSite Member
    from RI
    Messages: 137

  3. heritage

    heritage LawnSite Bronze Member
    Messages: 1,349

    Not an expert here but I see you have a LOW Cation Exchange Capacity CEC.

    Thats one of the things I look at as the Higher the CEC the better it holds on to some of the Essential Elements we apply.....Its the Organic Fraction of the soil that has a Magnetic Charge.

    Such Sandy soils will not hold on and will need to have Fertilizers applied more often and in a slower release form.

    If you add the Dolomitic Lime as recommended, it will add Ca, Mg and Raise the soil PH......This will help make some of that Tied Up P become available.

    Another Option which I would do to Raise the CEC is Topdress with Leaf Compost AND switch to a Chicken Poop based Fert.

    How much topdressing............about 1/4 - 1/2 inch Spring or Fall Annually.

    As the Topdressing/Compost breaks down the P will be more available as Organic Acids are put into Solution by The Soil Microbes that break down the Compost applied.

    This will also lower the Sodium and allow the soil to have a Stronger Magnet to hold on to the Ferts you apply...Raise CEC.

    This is especially true for the sandy soils you deal with on a daily basis.

    This is the simplest way to explain a topic than can get Complex VERY in a hurry.

  4. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,436

    I don't understand the high sodium levels--is it near where salt was used for de-iceing last year? If you get lots of rain, sodium should be low. Test in a different spot next year. pH is only slightly acid--not much lime needed--ignore this if you wish. You are on the right track with 19-0-19. Remember that the nitrogen will be leached out or used up in a few weeks, unless some of it is controlled release. The potassium likewise--heavy rain or sprinkling will leach it out. Low CEC indicates sandy soil, low organic matter or poor nutrient-holding ability. Plan to include potassium every time for a couple years.

    The real egghead soil experts will chime in soon, I am sure.

    Whoops. Now I see you are using a 60 percent MESA slow release nitrogen--good plan.
    Last edited: Jul 15, 2009
  5. godjwood

    godjwood LawnSite Member
    from RI
    Messages: 137

    Hi Pete,

    You say your not an expert but you sound like you are to me!

    You mentioned a low CEC- what is the range we are looking at here, what is considered "low", "normal", and "high"? So basically the way to create a more ideal CEC is putting down organic matter?

    You also mentioned putting down lime in the amount they recommended... do you mean the 11.2 lbs/acre? As I understand the ideal PH level is 5.5 to 6.5.. and this lawn is a 6.1.. so isnt it idea? If I put down lime isn't it going to push it out of this range? Is the idea behind putting down the lime only to correct the levels of Ca and Mg?
  6. godjwood

    godjwood LawnSite Member
    from RI
    Messages: 137

    I believe the reason the sodium is so high is because it is located about half a mile from the ocean.

    I still don't understand- things still seem so arbitrary.. i guess there is no concrete or correct answer to any of it? Multiple ways to approach the same problem?

    Maybe I just need to keep getting these soil tests and analyzing them and I will pick it up.

    So do you think I should continue putting down fertilizers with 0% Phosphorus for this entire season or what?
  7. heritage

    heritage LawnSite Bronze Member
    Messages: 1,349

    Look at your Ca%.....its like 46%. In sandy soils should be 60% and in Clays around 68% Base Saturation of the CEC.

    If you do not want to raise the Soil PH, but DO WANT to raise the Ca WITHOUT the Carbonate......In lime (Ca Carbonate) Then apply Pelletized Gypsum 25 Lbs per 1,000 Sq Ft OR 1000+ Lbs per acre one annualy until youe Ca Base Sat is around 60%.

    Myself I would go the Better IMHO/More Sustainable Approach with the Compost Plan I suggested..........You will have better Turf also IMHO as well as less Sodium Issues.

    If you go the Mineral Fert Plan, be sure in addition to the 1-0-1 Ratio Ferts with 50% Controlled Release, be sure to apply Sulfur as well (buy fert with % Free Sulfur) because low CEC soild have very low Organic Matter and this is where the Sulfur would come from in the Sustainable Plan.

    1 Lb actual Sulfur (NOT Sulfate) for every 10 Lbs Nitrogen Applied.

    I Strongly suggest you consider the Topdressing Plan.......The more you study the Soil Tests/Elements/Soil Physics, the more Obvious it will be.

  8. Think Green

    Think Green LawnSite Silver Member
    Messages: 2,746

    You all are good in helping out and dead on target, but I would like to know from JWOOD, did you take one sample from one spot or did you take random samples from different quads? I will take small samples from 6-8 spots at different quads of a lawn. Allow the materials to be combined and then send the soil in for analysis. My extension services advise not to take from one spot.
    The reason is, the entire lawns overall health cannot be revealed otherwise. Not all soil spots are the same, some areas are high in one material or another. Random sampling will make vast results composites and the results will be evenly gathered.
    We are in heavily rainy climate, and our salinic reports aren't high at all. I agree with riggle in maybe the sample was taken near the edge of the lawn where over splash of salt was deposited.

    The answer to your 19-0-19 fertilizer is a follows:
    Depending on what turfgrass you are fertilizing, down south if I were feeding Bermuda, the rate would be 1# of nitrate per 1,000 sq.ft. per growing month.
    Take the 1# and make it 100 and divide that number by the % of fertilizer N= 19
    100/19= 5.2 lbs. per 1,000 sq.ft.
    If you are growing shade grasses or cool season grasses, you may want to apply at a 1/2# per 1,000. Then you will want to apply 2.5 lbs. per 1,000 sq.ft per growing month.
    ( I am guessing on your turfgrass, but the math is the same. (The rate of Bermuda for my growing climate is correct.)
    Slow realease fertilizers change the pH slower than rapid release fertilizers do. Multiple uses of fertilizers will change the pH over time, so you can do another test next season to see if your application methods are improving or not.

    The lime appears to be 11.2 lbs. per 1,000sq.ft ??

    I apply it at 40-50 lbs. per K.
  9. gregikins

    gregikins LawnSite Member
    Messages: 9

    It is your K (potassium) that needs to be corrected. On low CEC soils I like to see that number above 130 ppm. I would not mess with the 19-0-19 to fix the problem . You will be putting on too much nitrogen to get the K level up to par. Find some 0-0-60. Ag suppliers should have it. Apply up to 6 lbs /1000. I would split this application in 2 treatments 6 to 8 weeks apart. 0-0-60 can burn the grass, this is the reason for the split. Applying right before a rain usually prevents any burn issue

    Then next year us your 19-0-19 fert to keep the K level up. Your low CEC is not going to hold the K well and you will need to applying so K every year. I would take a soil test late next year at least 2 to 3 months after any fert application to see where you are at with the K.

    I would not worry about the sodium. I like to see that below 40. The pH of 6.1 is fine for grass, but some of the other landscaping plants may benefit from a lime app. Be sure you know the plant and its sensitivity to pH. Putting lime around a rhododendron, azeala or blueberry is a good way to kill them. Here in Illinois I like to see the Mg above 100 and Ca above 400 so you are good there.

    P is high but fine. No worries unless you also have pH above 7.4 which will mess with the iron intake.

    Greg Ikins
    Agronomist United Soils, Inc
    Owner of M&L Lawn Care
  10. bug-guy

    bug-guy LawnSite Bronze Member
    Messages: 1,027

    i thought 6.5 cec in sandy soils is average

    In a laborartory, the number of electrical chargesw can be measured and is reported in units called millieequivalents per 100 grams. This is not an important piece of information. What does the CEC of soils tell us? Nothing other than soil texture. For example, sandy soils have a CEC of 5 to 7. Soils with a silt loam texture have a CEC of 10 to 12. Soils with a higher clay content have a higher CEC. These values change slightly with organic matter content–but not much.

    i would follw the recommendations with the lime and use low phos. fert

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