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sue_ct

Surprise Soil Test Results

sue_ct
12 years ago

I live in CT where native soil is generally acidic (my lawn was tested and had a soil pH of 4.5 last year and needed a lot of lime). But I used purchased compost in my raised bed, applied twice a few years apart and put my dried leaves there each fall. The leaves are from a maple and an ash tree in my yard. I never tested the soil, just tilled the compost and leaves into the native soil, until last month. This warm winter prompted me to go out on a warm day in Feb. and get soil samples from the garden and results were a surprise. They are:

pH 7.5

Calcium >4000 lbs/acre

Magnesium >500 lbs/acre

Phosphorus >100 lbs/acre

Potassium >600 lbs/acre

Boron 1.60 ppm

Copper 0.40 ppm

Iron 6.00 ppm

Manganese 103.00 ppm

Zinc 10.10 ppm

Aluminum 63 ppm

Soil Texture: Sandy Loam

Organic content: High

Note: Your soil nutrients are above optimum, mostly likely because too much fertalizer (either synthetic or organic) or compost was applied. Excessive nutrients can result in plant problems and also can contaminate ground and surface waters. Strive to keep nutrients in the optimum range.

Additional note: Do not any any lime, wood, ash or organic matter, composts or manure. Your pH is getting too high and nutrients are way above optimum! Too much organic matter in wet years can cause roots to rot and they will not be able to take up nutrients and oxygen properly.

This testing was done by UCONN.


On the plus side, I rarely have to water the garden with no wilting of tomato plants. The deep soil is sand. If you dig down about a foot anywhere you come to almost pure sand, so I guess that is why water logging hasn't been too much of a problem? Anyway, I mainly grow tomatoes, and want to maximize the fruit productivity and health of the plants. My garden is organic. I also grow a few herbs there like basil, and peppers. I have not had great luck with Bell Peppers but do a little better with hot peppers.

I am planning on bringing in top soil to add to the raised bed since I never filled it completely. The raised bed was built because the garden is on a hill and I want to level it to help with watering. So I have been slowly raising the level of the bed to level it off. I hope that will bring the soil more towards the optimum ranges for organic matter and nutrients. I will then need to have it retested.

Is this a good plan, or should I be doing anything else?

Comments (41)

  • wayne_5 zone 6a Central Indiana
    12 years ago
    last modified: 9 years ago

    With a sandy loam raised bed and sand underlying that, I am surprised that there is a concern about OM. Likely that is a prerecorded message. Still, you know best about that area.

    I can see that you have almost no clay with that aluminum ppm. Also I wonder if the phosphorus really is too high.

  • sue_ct
    Original Author
    12 years ago
    last modified: 9 years ago

    I really don't know anything about interpreting soil tests, so are you questioning the results of the Phosphorous or saying the results they got are not really too high? No, there really is no clay locally that I have heard about, and apparently not much in the purchased compost either? What should the aluminum be and what would indicate that clay was present? Are you implying I should find a way of adding clay?

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  • bi11me
    12 years ago
    last modified: 9 years ago

    There are certainly advantages to having a percentage of clay, mostly involving micronutrients, but not likely worth importing large amounts - a few bags of Montmorillonite might be all you want. Adjust your pH, and plant some heavy feeder crops that like good irrigation and you should have great results in your garden with those readings. My fathers' soil is beautiful glacial loam with sandy subsoil, with a very low percentage of clay, but it produces beautiful plants.

  • sue_ct
    Original Author
    12 years ago
    last modified: 9 years ago

    Thank you, Billme. This came up in part because I need to add more soil to continue to fill this bed to level it off and I wanted to know what I should add. I was going to get more compost but now think I should add top soil instead since they told me NOT to add more compost/organic matter. I also have a layer of dried leaves on top of the garden that I would ordinarily till in in spring, that I now think I should rake up to avoid adding more organic matter, which once again they told me not to do. I am trying to optimize productivity of vegetables, esp. tomatoes., and keep them healthier organically so I minimize disease. If I am going to bring in purchased amendments anyway, I might as well bring in whatever will do that instead of what it already has too much of. I will retest the pH after I add whatever I bring in. If the topsoil is acidic, or whatever I add it might change the pH some. I am hoping for help in determining if I am off base here. By the way a large portion of the leaves on top are ash leaves which I have read are high in calcium and I believe not very acidic, which would be better in this case.

  • leira
    12 years ago
    last modified: 9 years ago

    Well, sue_ct, if you're adding more (plain) topsoil, that will decrease the overall percentage of organic matter in the bed. So, even if you're buying the "don't add organic matter" story, I wouldn't remove the leaves. I'd just add the topsoil and re-assess later.

  • wayne_5 zone 6a Central Indiana
    12 years ago
    last modified: 9 years ago

    sue, I was only saying that the lack of aluminum indicates nearly no clay as clay has a lot of locked up aluminum in it...be it clay is both good and bad.

    Again, I am surprised at the cautions they gave you for sandy soil. I am no soil test person, but the phosphorous looks low to me...but I don't really know that, understand? I kind of wonder if some areas are kind of pc now about phosphorous.

  • sue_ct
    Original Author
    12 years ago
    last modified: 9 years ago

    OK, there is an underlying thread here that I don't understand. Is it supposed to be general knowledge that this is wrong? Is it and am I supposed to know that? What is going on? I feel like the chump that went to a gypsy fortune teller and everyone is looking at me with pity for my ignorance, but not telling me the truth, lol. "If you buy that story"?

  • pnbrown
    12 years ago
    last modified: 9 years ago

    Seems that some form of phosphate is called for, and magnesium is low also in relation to calcium I believe.

    Sue, you might want to go to AcresUSA and read about the Albrecht ratio of calcium, magnesium and potassium.

  • leira
    12 years ago
    last modified: 9 years ago

    sue_ct, there is a legitimate concern about people adding excessive amounts of chemical fertilizer (especially phosphorus) to their soil, to the point that it causes a problem with the environment. As I understand it phosphates cause algae blooms in the water, and that wreaks havoc with the other things that are trying to live there.

    However, if all you've ever added is compost and leaves, I just have trouble believing that you have soil that's a problem in this way. I mean...suppose you never did anything with your leaves, and they just sat on the ground under the trees, like they would in the forest. Would that be "a problem"?

    You say you used purchased compost, and what gets sold in the store as compost can sometimes be a bit questionable...so I guess you could investigate that.

    I'd also wonder a few other things. Did anyone garden in that soil prior to you? Could they have used excess fertilizer? Could there be run-off from a neighbor's garden?

    Did you carefully follow the instructions about collecting your soil sample? I know the UMASS site talks about collecting samples from several areas, letting it dry, mixing all of the soil together, and then sending in a measured amount. Is it possible that you got a "pocket" of something, and not really a representative sample of your soil as a whole?

    I also wonder if things go awry in the lab sometimes. I would be tempted to call them, tell them what your soil test said and also the particulars of your yard, and ask them if what they're saying is really believable, given the circumstances.

  • sue_ct
    Original Author
    12 years ago
    last modified: 9 years ago

    My soil testing was delayed due to equipment problems at UCONN and they were waiting for parts to fix it. Then they said the results had been sent twice when I called but they were not post marked until a week later, so they may have sat on someones desk for a while.

    I took the samples from at least 5 different spots 4-5" deep and mixed them together. I got the same or similar results from all the samples and I sent 5 or 6 from different gardens and from 3 different areas of this garden. I sent a sample from 5 mixed samples fromt the top of the garden and 5 areas along the bottom of the garden, and 5 areas from the shadier side of the garden. All were similar.

    I have used Miracle grow for tomatoes a couple times a year, but much less than recommended, which I believe is something like every 2 weeks, and fish emulsion a couple of times. That was over about 3-5 years.

    I mulch with something called "Mainely Mulch".

    I put this raised bed directly over the lawn soil after I removed the sod.

    The garden is down hill from the rest of the lawn. I don't fertilize the lawn directly around the garden or use chemicals there. I did use a lawn service last year, but they stated they stay 12-18" from any garden beds.

    I collected samples from the top and bottom of the garden separately at UCONNs recommendation because I had noticed plants at the top being smaller and less productive. There was not a significant difference in results, so I am assuming it might be a result of less water since the water runs down hill.

    This is a photo of the garden taken a couple of years ago:

    {{gwi:271008}}

    I want to add more soil to finish the bed and level it off more.

    Should I have the test repeated someplace else? Just add top soil and then retest? I don't know if you can see through the tomato plants, but the soil IS black. Probably has high organic content, maybe that is not bad? You can also see if you look closely the plant at the very top of the garden is shorter. Now the top 3-4 plants are shorter and less productive. Maybe just water?

  • bi11me
    12 years ago
    last modified: 9 years ago

    Sue - it's not a question of general knowledge, all of us have particular areas of experience and education, and can only relate to your situation from there. That being said, the same is true of soil-testing services... it may well be that a computer analyzes your results and spits out a rather formulaic answer. What you will see here are a variety of responses, sometimes conflicting, and you'll still have to sort through and find what works best for your situation. As Leira points out, there all sorts of parameters that may affect the situation, which you as the OP may not have addressed, or even known to address, so it is important to look at the responses as an analysis that will benefit from as many responses as possible. Eventually you will refine those answers into a plan that works for you. Organic amendments tend to be slower acting than synthetic ones, and soil test recommendations may make assumptions regarding your practices, and offer a more conservative assessment than an experienced gardener might - or not - and that is where discussions like this might clarify things - or not. I agree that the addition of top soil, should go a long way toward addressing the most serious issues; it should reduce the pH, presuming it is either neutral or acidic, which is likely, it will reduce the overall percentage of organic material, which in well drained sandy loam raised beds shouldn't be much of an issue anyway. Compost also tends to have a buffering affect, reducing the potential harm of less-than-ideal nutrients and pH readings, so it is possible for you to miss out on a very good outcome because you are seeking perfect levels. The best soil test is always the results of your harvest. Until then, everything is just data.

    I think your initial plan is the right one - add topsoil, grow some stuff, look at the results of the harvest, continue the conversation here, and retest in the fall, after the inputs have been incorporated into your garden. You'll have a better grasp of where you want to take it from there.

  • pnbrown
    12 years ago
    last modified: 9 years ago

    The real soil test is the taste of the produce, IMO, closely followed by the ability of plants to resist insects.

    One can to some extent calibrate one's taste buds by way of the refractometer. For example, if produce that brix tests in the medium range tastes good, then one is overly accustomed to typical grocery produce. If, OTOH, it tastes rather so-so, one's sense of taste is getting properly calibrated. A brix 6 tomato, for example is what I find the expensive "vine-ripened" ones in the store tend to be. People accustomed to garbage cheap tomatoes tend to think those taste great, whereas in fact 6 is middle of the range. If one's garden tomatoes are brixing 6 then not all is ideal in the soil and the plants are probably experiencing some mild health problems.

  • sue_ct
    Original Author
    12 years ago
    last modified: 9 years ago

    Thank you very much, bil 1me, that is what I will do. I will consider all input and reassess. I know so little about this stuff, I only know the most rudimentary stuff from home gardening over last 10 years, mostly compost and organic matter is good, ph can make nutrient not available to plants, too much nitrogen can result in lush green growth but not a lot of fruit/flowers, lol that type of stuff. The actual numbers of a soil analysis are meaningless to me, so it helps to have someone put them into perspective. I had never heard before that you can have too much organic matter, although the reason they gave, that it can result in too wet a soil in rainy seasons made sense. Knowing the underlying soil was sand, I didn't worry much about drainage. Sometimes ignorance is bliss, huh? Before the soil test I thought I probably had acidic soil with a fair amt of organic matter that might need a little lime and a boost of compost after 2 years, lol.

  • leira
    12 years ago
    last modified: 9 years ago

    Sue_ct, the high pH the soil test is reporting particularly surprises me...not only because of where you live, but also because you had your lawn tested, and it was so much lower.

    I agree with what others say that the real test is the results of your garden.

  • fortyonenorth
    12 years ago
    last modified: 9 years ago

    First, let me say that my conditions are very similar to yours. We live just down wind of Lake Michigan and our native soil is all sand. The pH and various nutrient levels are very similar to yours, so I think I can relate to your situation.

    I understand your frustration with the mixed and contradictory answers, but I think much of the disconnect is attributable to the different philosophies vis a vis soil testing. I'm pretty sure UCONN subscribes to the sufficiency school. Sufficiency advocates believe in adding fertility only when the addition will create a positive crop response, i.e. additional yield. It's really a "feed the plant" methodology. If additional fertilizer will not provoke better yield, then you have "sufficient" fertility. In your case, UCONN believes that you have sufficient (or excess) amount of all the significant elements.

    Above, pnbrown mentioned Acres USA and the Albrecht ratios. Dr. Albrecht and advocates of the base saturation school believe there is an ideal ratio of major cations in the soil. Cations are the base minerals calcium, magnesium, potassium and sodium. These amounts are not calculated purely by pounds per acre; rather, they are determined within the context of the soil's ability to hold or "adsorb" these cations. Heavy clay soils have more capacity to adsorb cations than a light sandy soil. So, while 4000 lbs. of calcium may be "too much" for one soil, it may be "not enough" for another. Dr. Albrecht believed that when the base saturation %s of the various cations were in the right proportions, the soil would be physically and chemically "ideal" for growing healthy, nutritious crops. In contrast to sufficiency's "feed the plant," Dr. Albrecht taught us to "feed the soil."

    So, what does this mean for you? I did a quick calculation of your base saturation %s and came up with roughly 75% Ca (calcium), 16% Mg (magnesium) and 6% K (potassium). UCONN's numbers weren't precise but, considering your pH, this is probably close. Albrecht's "ideal" %s are 60-70% Ca, 10-20% Mg, and 2-5% K. I would say, as a base saturation advocate, that your soil is not too bad at all. But I also understand why UCONN is jumping up and down yelling "too much, too much, too much." I understand, but I would choose to ignore them ;)

    What to do? Since you have excesses of all the major cations, the addition of elemental sulfur (90% S and available at any good garden center) will serve dual purposes: it will "shake loose" some of the excesses; and, at the rate of 3 lb. per 100 sq. ft., it will lower your pH roughly 1 unit. IMO, you're also low on phosphorus. Unfortunately, with a pH above 7, there are no organic sources of P that would be readily available for plant uptake. Stuff like bone meal, rock phosphate, etc. is generally more effective when the pH is below 7. If you're not a stickler for "organic" you could use some triple super phosphate at the suggested rate or at a rate of 1/2 lb. per 100 sq. ft.

    What not to do? I would not add a significant amount of top soil. Top soil is so variable that, unless your doubly sure of "what" you are getting, you could end up with something good or something very, very bad. It's generally impossible to know, so why risk ruining what you've worked hard to build. If I were in your place and wanted to "top off" my raised beds, I'd use pine bark fines, peat and a calcined clay product such as Turface. They are all excellent amendments that will provide much benefit to your soil.

  • bi11me
    12 years ago
    last modified: 9 years ago

    I told you there were some smart guys on here.

  • bi11me
    12 years ago
    last modified: 9 years ago

    Then there's aromatic herbs. Basil likes a bit of pampering to really shine, but Rosemary, Oregano, Marjoram, Thyme, and Savory often taste best when grown in what are commonly described as "poorer" soils. This is in part because of their provenance - they are Mediterranean natives, and accustomed to rather less than the ideal soils and moisture levels we gardeners seem to strive for, and so drier soil and more lean nutrients seem to result in more concentrated flavor. It is considered, by those who subscribe to evolutionary theory, that botanical flavinoids and aromatics were favored by the process of natural selection because bugs didn't like them - the fact that humans do may be happy coincidence or Divine Intention, depending on which side of the debate you fall on, but most herbs seem to taste better when they have to struggle a bit.

  • pnbrown
    12 years ago
    last modified: 9 years ago

    If you have only been adding bought compost and leaves, I am perplexed as to how calcium got so high. You never limed that area? No wood ashes?

  • mad_gallica (z5 Eastern NY)
    12 years ago
    last modified: 9 years ago

    The soil pH may be legit. To make a very, very long story short, the Taconics used to be sea bed. As happens quite often with ancient sea bed, a thick layer of limestone was formed. This was then lifted up to form the Taconic range, which has been eroding ever since. This was an absolutely massive amount of lime that had to go somewhere. A certain amount ended up in my backyard, and it is possible that some of it also ended up at sue_ct's. The difference between the lawn test and the garden test is strange, but one or the other may be fill from somewhere else.

  • gargwarb
    12 years ago
    last modified: 9 years ago

    did a quick calculation of your base saturation %s and came up with roughly 75% Ca (calcium), 16% Mg (magnesium) and 6% K (potassium).

    That really doesn't work for this sort of test. When calculating the base saturation cations, to determine if your soil fits the "ideal" percentages you need the total amounts: the stuff that's immediately water soluble, the stuff that's less soluble but extractable with weak acids (which are the numbers we see here since UCONN used modified morgan extract) along with the stuff that you can only extract via an aggressive extraction like quadruple ammonium acetate. When they say base "saturation" it's because the assumption is that all of the cation exchange sites on all of the colloids are occupied (saturated) and you want to know their ratios. Modified Morgan will only give you a slice of those numbers.Due to the variabilities in the species of cations in soils and what it takes to get them into a form that can be measured, there isn't a good correlation between the three.
    Your 75:16:6 via modfied Morgan could easy be a 50:40:10 or 80:5:15 if the soil were analyzed by a method that is used to determine cation saturation.
    I'm more of a sufficiency thinker myself but if you're going to go the balanced cation route, you need to use the right numbers. Otherwise you're comparing apples to oranges.

    Having said all that, I think the UCONN interpretation is pretty decent. The last thing I would want to do is add something that is already at or approaching excess in order to "balance" something else. That goes doubly so in this case, where the numbers used for that sort of interpretation aren't even available.

  • fortyonenorth
    12 years ago
    last modified: 9 years ago

    Thanks for the clarification garg. I don't mean to play loose with the numbers; I just wanted to highlight the different schools of thought. And, as I mentioned, I readily admit that UCONN's numbers are not precise enough for a true base saturation calculation. At the end of the day, I think we come to the same conclusion in this case - though I would think the addition of sulfur and some phosphorus would be advisable and I don't know if that was among UCONN's recommendations.

  • gargwarb
    12 years ago
    last modified: 9 years ago

    Sorry, reading further along in the post:

    But I also understand why UCONN is jumping up and down yelling "too much, too much, too much." I understand, but I would choose to ignore them ;)

    I wouldn't be so quick to do that. I would wait and see how the plants respond. At the values that you have I would say that it is very unlikely that you're going to see many deficiencies. I think adding something to chase a "balance" would be more likely to accomplish a few different things:
    1) It could (possibly, depending on the rate) result in an antagonistic deficiency of other nutrients. At 100 lbs./acre via morgan in a high organic sandy loam, adding too much more could potentially inhibit uptake of micros, especially iron, in a soil where the odds are already stacked against micronutrient availability due to the alkaline reaction.
    2) Applying inputs when they aren't necessary can (potentially) lead to pollution issues.
    3) All of the costs in money, time, transport, etc. of applying nutrients that are needed isn't financially or environmentally frugal.

    On the topic of the pH, it's tough to say how much sulfur would be needed to adjust the pH downward because it would have to neutralize the lime that you've applied before it even affects the pH. I also wouldn't sweat it too much because with a naturally acidic soil (4.5), the soil's own buffering capacity will shift the pH downward over time and a pH of 7.5 isn't the end of the world. I would just let it ride.

    On the subject of sulfur, it won't "shake loose" other cations for 2 reasons. First, you would be depending on "mass action" to displace the cations. 3 lbs. per 1000 sq. ft. of anything isn't going to do a whole heck of a lot of displacement. Also, as sulfur goes into solution in the soil it is converted primarily to sulfate (either as a free sulfate (SO4), sulfuric acid (H2SO4) or some other sulfate salt (calcium sulfate, potassium sulfate, etc.) very quickly and, being negatively charged, will not take up any room on the exchange, must less displace anything. That's why you don't see sulfur reported as part of the saturation cations ;)
    Of course, the term "base cations" can be confusing and one might think it doesn't show up in that list because sulfur acidifies the soil. I'm not going to get into it now but that's not what the term really means (I have a couple of previous posts that address base cations. A thorough search would probably turn one up) In fact, in acid soils, you will see hydrogen reported as a percent of the base saturation extract and acidity is all about hydrogen.

  • gargwarb
    12 years ago
    last modified: 9 years ago

    Oops, didn't mean to steam roll right over your most recent post. I tend to type a little, walk away and do other things, then come back to type some more so I'll miss other peoples' posts sometimes. Sorry 'bout that.

  • gargwarb
    12 years ago
    last modified: 9 years ago

    And a correction....

    3) All of the costs in money, time, transport, etc. of applying nutrients that are needed isn't financially or environmentally frugal.

    Should read: "aren't needed" or "may not be needed"

  • gargwarb
    12 years ago
    last modified: 9 years ago

    Holy molly, I just realized the given rate for sulfur was 3 lbs. per 100 sq. ft., not 3 per 1000. That's a very aggressive rate, especially for a naturally acidic soil. Please do not do that.

  • gargwarb
    12 years ago
    last modified: 9 years ago

    Sorry for gumming up the thread but I'm trying to do too many things at once this morning and missed a lot of stuff.

    From the O.P.
    my lawn was tested and had a soil pH of 4.5 last year and needed a lot of lime). But I used purchased compost in my raised bed

    I mistakenly took that to mean that lime was intentionally added. It doesn't look like that was the case. However, I do agree with pnbrown. Where did all that calcium come from? That, along with a sharp increase in pH sure looks like lime. What do you know about your compost? If it contains horse bedding that might explain it since lime is often used for odor control in stables.

  • fortyonenorth
    12 years ago
    last modified: 9 years ago

    On the subject of sulfur, it won't "shake loose" other cations for 2 reasons. Fair enough - poor choice of words. I wasn't suggesting that sulfur, as an anion, would replace any cations. But, isn't it true that it will bind with "free" cations (those not held on the colloid or OM) to form magnesium sulfate, calcium sulfate, etc. and carry those along when it leaches through the soil profile?

    On the subject of application amounts, I did a quick check and rates are all over the place. Clemson suggests 4 lbs per 100 sq. ft to lower a pH 7.5 one unit. Given the current pH, and as you pointed out the amount of Ca in the soil, do you really think 3 lbs. is excessively high?

    BTW - I appreciate your level of knowledge, Garg. I'm not arguing, just trying to clarify things in my own mind.

    Good thread everyone - cheers!

  • gargwarb
    12 years ago
    last modified: 9 years ago

    But, isn't it true that it will bind with "free" cations (those not held on the colloid or OM) to form magnesium sulfate, calcium sulfate, etc. and carry those along when it leaches through the soil profile?

    Maybe a tiny bit but as you noted, it will only react with some of the more soluble stuff. It's not going to touch anything that is bound to the exchange. I think the over all effect would be pretty negligible

    Given the current pH, and as you pointed out the amount of Ca in the soil, do you really think 3 lbs. is excessively high?

    Oh yeah, and due to my location, the vast majority of what I deal with is with alkaline soils. If there was a lot of lime in the soil (we still don't know where all the calcium is coming from) I would go with about 1 1/2 to maybe 2 lbs. to get the pH into the ideal slightly acid range. Without lime in the soil, I would go somewhere between 1/2 and 3/4 lb. But again, if the soil is naturally acidic in that area and the higher pH is due to lime application, the soil will buffer its own pH down over time. However, Mad_Gallica also threw out some very interesting regional knowledge that may be worth looking into.

    I'm not arguing, just trying to clarify things in my own mind.
    Absolutely, I think it's great that we can all bounce this stuff off of each other and kick it around. Even the disagreements are valuable. It gets everyone thinking, which is a very good thing. Whatever people decide to do in the end, they are making more informed decisions than they otherwise would have.

    (besides, it would be boring if everyone agreed all the time)

  • wayne_5 zone 6a Central Indiana
    12 years ago
    last modified: 9 years ago

    I'm also thinking that the soil type makes a large difference when adding things like lime and sulfur. I believe it takes a lot more material to saturate clay soils than sandy soils.

  • gargwarb
    12 years ago
    last modified: 9 years ago

    I agree. The higher the clay and organic content, the more sulfur /lime you need to make a change. We have a texture of 'sandy loam' on this one, which is a pretty broad category (That's part of the reason I went a little "weasely" and gave sulfur rates as ranges.)

  • fortyonenorth
    12 years ago
    last modified: 9 years ago

    As I mentioned in a previous post, my conditions here seem to be similar to Sue's. Our native soil is sand and acidic. The pH of my raised beds - heavily amended with compost and manure - are much higher. I think the key here is that if you're sampling at ~6", you're not sampling native soil at all - save for what's incorporated in the raised bed. I don't find it surprising that the pH in the raised bed is radically different - it's essentially imported soil, right? For the same reason, I wouldn't expect the native (acidic) soil to affect the high pH too much. Sue's particulars could be somewhat different than mine, but that's what I've experienced.

  • sue_ct
    Original Author
    12 years ago
    last modified: 9 years ago

    Yes the majority of the soil in this bed is imported, because I have brought in 2 truck loads of purchased compost over 3-5 years. I am not positive how long ago I built the bed but it is over 3 years. I did initially till the the compost into the underlying soil, but since I was using a mantis, I am sure it could not be considered deep tilling. So even initially it was mostly imported compost. Then I imported more. :) About 3 yards into this bed. I have not recently added lime. I can't swear I never did, I may have added some in the past when I did the lawn, assuming if the lawn needed it, and given the pine trees and needles nearby, that the garden did too. I am just not sure. Around here soil needing lime is kinda like plants needing water, if you haven't done it in a while, it probably needs it. Baaaad assumption with purchased soil, huh? Dumb and dumber...

    But I DO need to add a significant amt of soil of some type. The slope is still too steep, watering difficult, and plants down hill do much better than plants at the top. So I really need to level this somehow and was planning on bringing in at least 2 yards of SOMETHING. Wouldn't that be too much pine bark and peat? I could certainly add a few lg bags of purchased peat in addition. I can do this fairly early and repeat a soil test right after. This time I plan to use the free local state agricultural experiment station that I didn't know about before I cut a check to UCONN. I do need to do it early though because turn about time they said quickly goes from a little over a week to a month or more.

  • Kimmsr
    12 years ago
    last modified: 9 years ago

    Your soil should have a humus level of between 6 and 8 percent, many times soil test labs seem to think anythning over 5 percent is too much. Here ae some simple soil tests you can do that can help.
    1) Structure. 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. 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.

    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.

    Since "topsoil" is the top 4 to 6 inches of soil it can be anything, so before purchasing any take a good look at what you are getting. We have a company here that is dredging the eons accumulaion of organic matter from the bottom of one of our lakes, mix that with sand and some lime (they send samples in for pH testing and then tell you that soil is state tested) and then sell that to landscape supply companies that sell it as "topsoil".

  • pnbrown
    12 years ago
    last modified: 9 years ago

    Can't tell how long your garden is in the photo, but what about cut-and-fill by shovel? Take half the slope in dirt from the top and toss it on the bottom, thereby making it level, with a new little shelf cut at the top which will protect seedlings from wind in any case.

    I have a sloped garden and I cut in level beds a lot that way.

  • leira
    12 years ago
    last modified: 9 years ago

    OK, sue_ct, the picture is becoming clearer.

    When you said you'd added compost, I was thinking you "amended" with some compost, not that you bought yards of it, and that it made up a significant percentage of your garden "soil." That really is quite a bit of organic matter!

    Also, lots of imported soil could explain the huge pH difference. I guess I was thinking that more of your soil had come from another part of your yard. I also wonder if any of the places that sold you soil "helpfully" mixed in fertilizer.

    So...considering that, let's re-think. I really like pnbrown's "cut and fill" idea for leveling stuff out. If you do that, you'll have more consistent results across the entire bed, even if you do add more stuff on top later. I think consistent soil across the bed can be good for the sanity.

    Personally, given the high levels of organic matter there already, I would add more topsoil. Of course, one thing about topsoil is that you never quite know what you're getting when you buy it, so you might look to a reputable garden center, or otherwise do your research. However, organic matter will just shrink away over time, leaving you needing to add more yards of stuff again later...but actual dirt, or "mineral soil" will always be there. For growing in the ground, which is what you're doing, I would aim for a bed made mostly of dirt, with plenty of organic matter mixed in, and not mostly organic matter.

  • sue_ct
    Original Author
    12 years ago
    last modified: 9 years ago

    Thanks, everyone. The cut an fill approach I have tried and it is just too much work for the amt of leveling to be done and would leave a "drop off" at the top. Not into building even small retaining walls inside my garden. All things considered, surprised I have had as healthy plants as I have so far. I am using a reputable garden local center that is geared towards landscapers. A little pricey but clearly seems to be favored by "the trades" over local big box stores.

  • pnbrown
    12 years ago
    last modified: 9 years ago

    That "drop-off" at the top gives a lot of wind protection to young plants, however.

  • ssmdgardener
    12 years ago
    last modified: 9 years ago

    Sue, you said you used a lawn service last year.

    Even though they didn't treat the lawn around the garden bed, isn't it possible for whatever they sprayed (fertilizer, lime, etc.) to have trickled down to your vegetable garden?

  • leira
    12 years ago
    last modified: 9 years ago

    sue_ct, I understand about the work! It might not be as bad as you think, though...but then again, I don't know your soil.

    pnbrown's point about wind protection is a good one, but I like the idea even if you do plan to top up with imported soil. My own slope is much shallower than yours, but this is exactly what I've done. I'm a big fan of making use of the native soil as much as possible, and the cut-and-fill approach keeps your native soil more evenly spread through the bed. Then, when you did add organic matter, you wouldn't have a situation where part of the bed was "lots of dirt with a little organic matter" while another part was "all organic matter with native soil buried far below."

    HOWEVER, all of that being said, let's remember that you're also reporting that you're getting great results from your garden the way it is. Don't let a little piece of paper from the soil-testing lab convince you that's not so. I don't think any of the approaches being bandied about here (including what you've done in the past, or are talking about doing in the future) are actively bad, and I suspect you'll still have a great garden on the other end of it, no matter what approach you choose.

  • sue_ct
    Original Author
    12 years ago
    last modified: 9 years ago

    Thank you, I have learned a ton here!

    Itching for REAL spring...

  • pnbrown
    12 years ago
    last modified: 9 years ago

    That bit about the Taconic range is quite interesting. Need to know more.