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sunshine_1621

soil testing - confused...

Hello,

I went to a local nursery yesterday where they test pH for free, turns out 2 out of 3 areas were normal, but the outlier sample's pH was around 6 - she told me to add lime.

After further research, I read that it's not that simple and you should instead get a soil test because something in your soil is skewing that pH. So, I've been looking online:

http://soilhealth.cals.cornell.edu/extension/test.htm#when

It appears that I'd have to pay at least $50 for a test. The ones for cheaper wouldn't really give me the info I'd need, right? Is this really what I should be paying?

I have a fairly large plot I wanted to plant in next year (around 600 sq ft [acidic area probably is 400 sq ft of that]) and I'm feeling a lot of pressure to get this amended before winter comes - I actually don't think I have time since the test results take 5 weeks. I just don't want what I plant next year to deteriorate because of the soil condition. So far just about a month ago I tilled in the area and added some compost and now I have cardboard over the top - that's how it was going to remain thru winter. Do I need to amend now? Is this as big of an issue as I think it is? Should I get the $50 soil test? My mind is racing.....

Comments (22)

  • 11 years ago

    Definitely chill out.

    In general, eastern soils are acidic to very acidic. Anything above about 5.0 can be considered 'normal', and a lot of people just assume a pH of between about 5.2 and 6.2 . However, north of the terminal moraine, anything goes, and pH as high as 8 isn't unknown. None of this means the soils are generally out of whack, or that anything is missing. What it means in real life is that you have to be careful about plopping down plants that want acidic conditions. I am assuming that what the nursery person considers 'normal' is around 7. Rhododendrons, azaleas, blueberries and other things like that don't like a pH that high, and either should be avoided or fussed with extensively.

    If you want to know more without paying a lot of money, see if you can find your county's Soil Survey. This gives a thumbnail sketch of soils in your area. If you can't find it, or don't understand it at all, give Soil & Water a call.

    It sounds like most local soils are fairly neutral. Here, the assumptions that soils are acidic rules. All my soil tests have come back with the same pH - 7.2. Most local nurseries, and Cooperative Extension do not understand this at all. Soil & Water saved my sanity on this issue.

  • 11 years ago

    Logan Labs gives a complete test for $25. There's a guy over in the lawn forum that reads this test (only) for free and makes recommendations for correcting everything which of course leads to a more neutral PH.


    Azaleas and blueberries love PH 6 :-)


  • 11 years ago

    I read the link provided by Lauren and have to say I found the Cornell site offers many different soil sample measurements and to me was very confusing.

    IMO $50 is too much for a garden soil sample. This is the sample I think she is talking about below...

    >2015 Cornell Assessment of Soil Health Packages

    Details of the testing procedures for the individual soil analyses can be found in the testing section of the Cornell Soil Health Manual. (For soil respiration and protein, follow links below.)

    Basic Soil Health Analysis Package

    Cost: $50 per sample
    Sample size: 3 cups
    Recommended applications: field crops, dairy, lawns

    Includes these tests:

    • Soil pH, Organic Matter, Modified Morgan Extractable P, K, and micronutrients
    • Wet Aggregate Stability
    • Soil Respiration
    • Surface, sub-surface hardness interpretation (Optional: You provide the penetrometer readings.)<
  • 11 years ago

    "Recommended applications: field crops, dairy, lawns"In other words, the soil testing is aimed at large areas that can be treated as one monolithic sample in the whole. Gardening is all about small individual spots as long as the pH isn't extreme and there's not a huge load of free calcium in the dirt. It's hard to force soil to another radically different pH, and avoid adding lime to a 6.0 soil unless you are desperate to really push the soil high and spend money. Maybe just pseudo-buffering it with LOTS of OM would be a prudent approach, particularly if overwintering the OM.

    Agreed that a 6.0 pH is still "normal", and that garden centers LOVE to sell you useless remedies such as pH modifiers, weed killers, and (of course) unneeded fertilizer.

  • 11 years ago

    Thank u guys so much, I was getting a little stressed. I am planning to put perennials and shrubs in this area... no crops, no azaleas, or any of the other well known acid lovers. I think I'll dump another load of compost in the area as well as some apples from my tree... maybe that'll help a bit. Not sure if this means anything or not but this area was like the dust bowl before we worked it this year, and there was landscape fabric stuck in there with tons of weeds... some of the worst soil I've ever seen so I guess I'm not surprised that it wasn't reading neutral. I think organic matter is definitely the answer. Thanks!

  • 11 years ago

    <I think organic matter is definitely the answer.>There it is...

    Me too. Can't go wrong with compost. Would be helpful to know what the N,P,K of the soil is but your plants will tell you that too.

    afaik, shrubs of the unknown variety aren't real fussy. ;)


  • 11 years ago

    The basic soil test from Cornell, soil pH, Phosphorus, Potash, and micronutrients, along with some other, probably unnecessary tests and they charge $50.00 per sample for that. Along with that you can talk with the horticultural agent at your counties Cooperative Extension Service office about that soil test.

    The soil pH for most all plants is in the 6.0 to 7.0 range, and with yours at 6.0 there probably is no need to apply any lime. Did the person at that nursery give any indication of how much lime to apply? Did that soil test include organic matter?

    Perhaps these simple soil tests may be of some help,

    1) Soil test for organic
    material. From that soil sample put enough of the rest to make a 4 inch level in
    a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and
    replace the lid, tightly. Shake the jar vigorously and then let it stand for 24
    hours. Your soil will settle out according to soil particle size and weight.
    For example, a good loam will have about 1-3/4 inch (about 45%) of sand on the
    bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above
    that, and about 1/4 inch (about 5%) of organic matter on the top.

    2) Drainage. Dig a hole
    1 foot square and 1 foot deep and fill that with water. After that water drains
    away refill the hole with more water and time how long it takes that to drain
    away. Anything less than 2 hours and your soil drains’ too quickly and needs
    more organic matter to slow that drainage down. Anything over 6 hours and the
    soil drains too slowly and needs lots of organic matter to speed it up.

    3) Tilth. Take a handful
    of your slightly damp soil and squeeze it tightly. When the pressure is
    released the soil should hold together in that clump, but when poked with a
    finger that clump should fall apart.

    4) Smell. What does your
    soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant
    odor? The more organic matter in your soil the more active the soil bacteria
    will be and the nicer your soil will smell, to a point. Too much organic matter
    can be bad as well.

    5) Life. How many
    earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5,
    according to the Natural Resources Conservation Service, indicates a soil that
    is not healthy.

    kimmq is kimmsr

  • 11 years ago

    You could always work in some crushed egg shells. They're a calcium carbonate (alkaline) source that are freely available, won't turn to caustic lye, and release slowly. It would be a gentler way to bring your soil's pH up in tiny adjustments, if you really want to.

    I don't think you could go wrong with adding more compost, though.

  • 11 years ago

    thanks!

    kimmq - I actually did the jar test last year and it was hard to determine the layers because they all looked so close in color and texture. As for the drainage test, did that too and realized I DEFINITELY have some poor draining clay soil as the water still wasn't gone in 24 hours!

    and, no, the test didn't include a measurement of organic matter, just pH. I told them I was going to plant perennials and shrubs and they just told me I should add lime, didn't mention how much.

    I guess I've learned to take the results from these tests with a grain of salt!

  • 11 years ago

    For gardening and everything else, my policy is to never take advice from someone who has something to gain from one or more of my options. I wouldn't trust a seller's test.

    I have, on occasion, gone to a competitor and said "I will not be buying anything here today. Here's a $5 tip for your time. Now, which is the appropriate product, now that you don't have a stake in it?"

  • 11 years ago

    Soil pH, Organic Matter, Modified Morgan Extractable P, K, and micronutrients Wet Aggregate StabilitySoil Respiration Surface, sub-surface hardness interpretation (Optional: You provide the penetrometer readings.) The first line here is what you really need. The other three are unnecessary for garden soil. In fact, I have never heard of the second and fourth in relation to growing anything. Stability and the use of penetrometer data sounds more like soil mechanics measurements for construction purposes. Soil respiration...well it's important, but there is no reason to measure it for a garden. If you can get just the first line, you're in business, and it should cost more like $20-$30. If you find you want to add lime to raise the pH, and the testing lab can't give you a recommendation, search online for 'lime application rate calculator'.

  • 11 years ago

    There's a couple of things in the OP's first post that prompt some clarification as the terminology used can certainly lead to some serious misunderstanding.

    First, the statement "test pH for free, turns out 2 out of 3 areas were normal" asks the question of what is "normal" when it comes to pH. There is no such thing as a "normal" pH - it is what it is. But there is such a thing as a "preferred" soil pH and that preferred pH for the vast majority of plants is in the range of 6.0 to 7.0.

    The second statement: "I read that it's not that simple and you should instead get a soil test because something in your soil is skewing that pH" also indicates that some misinformation is being gathered or absorbed. pH is seldom "skewed" by soil conditions unless the soil has been highly worked/amended/fertilized. And I would never consider a pH of 6.0 to be particularly skewed one way or the other. pH of soil is a natural reflection of the indigenous soil qualities. If the underlying mineral content of the indigenous (native) soil is based on acidic rock material (e.g. granite), then the soil pH tends to be acidic. If the mineral content is derived from more alkaline rock material (e.g. limestone), then the soil pH will be higher - more on the neutral to alkaline side. Annual rainfall levels factor in as well - areas with heavier rainfall will tend towards more acidic conditions; more arid areas tend towards the more alkaline conditions. The combination of the underlying mineral content of the soil and the amount of annual rainfall are the primary determining factors of a soil's pH.

    Changing a soil pH to any significant degree is extremely difficult to accomplish and will be a temporary fix at best. Many soils have a buffering capacity that resist significant pH changes and all will eventually return to their indigenous pH unless amending to alter is continuous.

    Additions of organic matter to any soil will help to neutralize pH to some extent but don't expect big changes. If you are just planting perennials and shrubs and not anything demanding very specific pH conditions, then I wouldn't even bother with the lime for the 6.0 area (can't say about the "normal" areas, as we have no idea what that means). A pH of 6.0 is a perfectly acceptable level for a huge range of plants. If it starts dropping much below 6.0 or is much above 7.0, then you might want to amend to alter as best you can (with lime to raise; sulfur to lower). But otherwise, you really do not need to do anything. Except add organic matter, which is good for any soil.

  • 11 years ago

    sorry, I always assumed 7 to be 'normal' so that's what the 2 other readings were.

  • 11 years ago

    7 is considered to be "neutral" as it is in the middle of the (scale) range. Perhaps that is what Lauren means by normal?

    For some that plants may be a bit high. Be sure to research on line or with your local extension office BEFORE you purchase the desired plants. Try to use the name for the specific plant.

  • 11 years ago

    As gumby notes, a pH of 7.0 is only a neutral reading (neither acidic nor alkaline) but not "normal" - normal is whatever is typical for your area.

    And as noted in previous responses, the vast majority of common landscape plants, as well as most edible crops, prefer a soil pH in the 6.0 to 7.0 range. That is the pH range where required plant nutrients are most readily accessible and where soil biology is most active.

  • 11 years ago

    good to know, thank you. Will proceed with the compost...

  • 11 years ago

    PH is one test you can do reliably at home. I think a test where you use a square test tube thing and a reagent and then compare color is easiest.


    That said, your result isn't that out of line. I would default towards more basic, less acidic, horticultural practices. For example, there is no reason for you to use ammonium sulfate as a fertilizer. Do you like potatoes or blueberries? Go for it.

  • 11 years ago

    Having a variety of conditions within your plot is, in my book, a distinct advantage and not something that needs 'fixing'. I would love a spot where I could grow plants which prefer a more acidic soil. Camellias without yellow leaves, Hydrangeas with blue flowers rather than dirty pink, scented Azaleas, Kalmias, heathers, blueberries .... just imagine.

  • 11 years ago

    Agree w/Floral.

    <PH is one test you can do reliably at home.> Me thinks the consensus here is the home soil test kits are a waste of time and money. Not only are they prone to misuse errors but the water used (which will vary) will skew the results which are hard to interpret.

    At least with the kimmsr jar test you are just wasting your time. ;-)



  • 11 years ago

    There are a number of tests for soil pH being promoted such as using vinegar, baking soda, litmus paper, or a store bought soil test kit and they all give some indication of what a soils pH might be. None however tell you why the soils pH is where it is ands what to do to correct if the pH is too low or too high. Do you use Calcitic lime or Dolomitic lime? How much is to be applied? Applying the wrong type of lime, too little, or too much will not necessarily help. Egg shells may help over a very long time, but neither the lime nor the egg shells will turn into lye. The liquid obtained by pouring water over wood ash is lye.

    Whether the soil test using the 1 quart jar is of use depends on how you understand what you are seeing. If there are no distinct layers then the soil is all one type, all sand, all clay, or what ever. The primary use of that test is for an indication of the amount of organic matter in the soil. A more accurate test for that would be to take a sample of soil, weigh it, burn that sample to eliminate all the organic matter, then weigh it again and calculate the percent by the difference in weight between the samples. For what it is worth I was given those simple soil tests many years ago by someone with a phD in soil science as tests to use along with a good reliable soil test from a good soil laboratory.

    kimmq is kimmsr

  • 11 years ago

    How odd - in the pulling weeds thread you wanted to debate burning weeds yet feel it is fine for a soil test?

    I guess many of us just don't understand what we are seeing.