My soil testing uses a different measurement I guess, so you would have to find out what their index is referring to. For instance, my Ca, P, Mg, and K are always listed in PPM, so I can't really comment there.

As for the others, they seem to be about right. 10% organic matter is quite good, but your cation exchange seems a touch low.

My first concern is the time of year that you chose to do the sample. Frozen ground does not lend itself to sampling properly. Ideally, your sampling is completed in the late spring or early summer as the soil has warmed and biological activity is kicking into high gear. By sampling frozen (and effectively biologically inert soil) you are unlikely to get a thorough picture of your soil. For instance, cation exchange is largely dependent on soil moisture, structure, and activity. When you are pulling the top 3" off of a frozen soil, I'm surprised you got numbers that high to be honest.

Wait until spring and do another test. I bet the results will be more comprehensive.

Michael

Cations are held by the clay and organic matter. So clay type and amount plus organic matter determine CEC. That isn't your problem.

Usually P, K, etc are listed as ppm. Can you give the basis for "index"? Is anything above 100 excessive? Even if these are excessive it usually won't cause a problem like Excessive Na or Cl would.

That pH is extremely excessive and along with the high P is most likely limiting Zn (important) and Fe (very very important).

A high P reading isn't neccesarily bad, but the flipside is the high P can also limit Fe uptake. Along with the high pH your plants might be suffering from this.

You want to get your pH in the 5.5-6.5 area and that might take more than one growing season. Once the pH lower, nutrients that are being tied up in the soil should be more available to your plants.

Step 1 is definitely taking care of that pH, though.

Or you can plant asparagus in there, cover with wood chips, and never tend that part of your garden again except for harvesting. The asparagus will love it there, and it is easier than playing little chemist.

I have no experience with soil testing, so take this for what it's worth. Others will need to say if I'm on the right track or not.

You note that the soil has had an annual addition of oyster shell. Oyster shell is composed mainly of calcium carbonate. I believe it has magnesium as well, probably as magnesium carbonate. I don't know about phosphorus and potassium. Could overuse of oyster shell lead to high pH as well as an excess of some minerals?

Jim

I have no experience with soil testing, so take this for what it's worth. Others will need to say if I'm on the right track or not.

You note that the soil has had an annual addition of oyster shell. Oyster shell is composed mainly of calcium carbonate. I believe it has magnesium as well, probably as magnesium carbonate. I don't know about phosphorus and potassium. Could overuse of oyster shell lead to high pH as well as an excess of some minerals?

Jim

Ok! here is my couple of pennies worth.

PH is way high. 7 is nutral, that is alkaline and acid balance out. Above 7 is alkaline, below 7 is on the acid side. My reading on the subject tells me that most garden veggies like slighty acid soile. a ball park figure to suite every thing is PH = 6.7 . That is ideal. a range of 5.8 to 6.9 is OK maybe for 90% of garden vegetables.
When the PH is too high or too low some of the nutrient will not be avaailable for the root system and alot of micro-organism will not thrive in those conditios. Actually, it is better to be on the acid side than alkaline side. My garden soil has bees around 5.8 and have grown good crops but I have been trying to raise the pH by adding wood ash and gypsum. Probably I have got it up to 6.5 this year.

Thanks for the input. Think I'll wait til spring and re-test. I actually paid for 5 more tests and have the kits.

Te testers at U of Delaware only suggested adding nitrogen by using urea. They suggested the same years ago and I just added compost with good results. I wonder if too much nitrogen might just lead to leaf production without vegetable production? Or does nitrogen availability need to be supplemented even with good organic content?

Our garden soil and also the lawn consistently test pH = 7.6. We live in Madison, Wisconsin, and we have hard water. Our soil has been described as calciferous, likely due to the limestone bed that lies underground, and covers pretty much the entire southern half of the state. At this time our yard is covered in snow, only the cedar out back is green. But soon, the lawn will green up, and our garden will be planted with tomatoes, beets, beans, lettuce, swiss chard, broccoli, and brussels sprouts. I expect the garden to be more or less successful, just like it has been for the past 10 years or so. We also have raspberry bushes, and a red currant bush. All of these plants do fine in our soil. Our blueberry shrubs are another matter, they need soil pH below 6.5, preferably below 6, and it takes some effort to achieve this. However, I have never done anything to lower, or raise, the soil pH in our garden. The garden gets a good dose of compost every spring, and thats it, other than watering during the August drought.

I, too, have 'high' pH (7.8) but I'm able to grow corn, potatoes, melons, tomatoes and green peppers without trouble.

If that were my garden bed, first thing I'd do is stop adding stuff to it. Obviously it has nutrients. Try planting something easy in that bed without adding any of the Bumper Crop stuff.

I also have "high" pH at 7.8 to 8 and have no pH problems generally. Raspberries often get a little iron chlorosis, but the garden veggies never show any signs of deficiency. Your organic matter is outstanding. Mine is naturally 1% or less, I've raised it to around 4% by adding a lot of rotted manure and other organic material, but that started causing some problems with salt levels and pushed some of the other nutrient ratios way out of whack, leading to some symptoms of deficiency in some trace elements due to oversupply of others. I've backed off on adding organic matter as a result and things are straightening out. I'm not suggesting your organic matter level is too high, but that if you are adding large amounts each year you should give the soil a break and let it balance itself out a little with time.

I am curious about what the "index" values are referring to. Normally you would expect the calcium Parts Per Million to be 3-4 times the magnesium PPM. If the indexes can't be translated into a PPM ratio of 3-4, then you need more. You may want to back off on adding significant additional organic matter (especially if it is from composted manure) for a year or two and consider adding some calcium as both gypsum and lime. The lime will try to raise your pH, but the gypsum will tend to offset that. The oyster shell is likely to contain some magnesium which you don't need.

Also get another test when the ground thaws. Your samples should cover the top 6" to the top 12" as long as that doesn't put you into the subsoil, and make sure they represent the entire profile uniformly--not 30% of the sample from the top 1" and 10% from the last inch, which can easily happen using a shovel to take the sample.

Very interesting.
All this time, all the textbook type information I have read say that slightly acid soil is ideal and preferred by most garden vegetables, shrubs and trees.
Now we hear successfull gardening with PH of 7.6 and higher.
Am I confused ? You bet I am.

It's been a long time since I thought about this stuff, but I have a foggy recollection of thinking that pH up around 8.0 and above is "bad" and so is a pH down around 6.0 and everything in between is sort of more or less OK. This memory is from back when I was sitting in the woods taking pH readings from the base of several hundred flags (three times for each flag to ensure accuracy) as a field research assistant. So anyway, there is a range of pH which life can live normally in. I think the books are saying there is an ideal range (slightly acidic) for veggies but that does not imply that all pH outside that ideal range will lead to failure. "Preferred" is not "have to have" I think. Does that make sense?

Cheers!

Sunni

Those old books that the USDA or their predecessors passed out to some farmers back in the 1930s had sections on educating people about such things as pH. There are some archived at the Nevada State Library in Carson City that say gardeners and farmers should not be discouraged if pH test came back as high as 8. But back there back then what choice did they have other than switching from plants to cows?

My personal opinion based upon, admittedly, only one course in college level soil science is that unless one knows how to tinker with cation exchange capacity one should, in most cases, learn to be happy with whatever pH one has.

I have a pretty good supply of pine needles from my trees and will mix some into the soil in the spring. Apparently this will lower pH a bit according to a couple books I checked.

It was my understanding that a soil that lacks organic matter is where pH matters more. The OM and related soil additives add buffer capacity to the soil's ability to provide trace nutrients like Boron.

Soils that are high pH, and lack organic acids, can cause metals to remain chemically bound up in soil (metals that are required by a plant. Iron, for example). But when there are plenty of organic acids that help break up the binding of metals to soil molecules, plants can get those trace metals via organic acid mediated exchange.

I dimly remember college chemistry where certain chemicals were added to a chemical solution to enable or enhance the chemical reactions. These were called 'buffers'.

kimmsr constantly pounds on this specific topic; use lots of compost. About that he is exactly right.

I looked up a link about buffers. It does a better job of explaining.

Here is a link that might be useful: Wikipedia link about buffer solutions

It is most difficult to get a clear picture without knowing the units employed for the report. A casual glance does not show any major ratio imbalances.

Lay off the ammendments for a couple years, repeat the test with the same testing source. Compare the reports and work from there.

The pH is at the upper range for most nutrient availability flows. A planting will draw off some of the nutrients and influence (modestly) the OM%, pH and CEC. The whole of the report usually changes when active plant growth comes into play. Not to worry.

It would be interesting to see any recommendations they offered.

Re: CEC The number suggests fine particles, perhaps the humus or even a clay topsoil. The strong OM% is a likely influence.

Go with it as is and monitor for pests and diseases. If a serious problem then there may be a limiting factor for trace elements. A garden journal would be a good record of rains, temperatures, waterings and employed mulches, etc.

Keep your eyes attuned to pest and disease symptoms.

What are you planning to grow? Good luck.

I have found an opportunity here to learn about soil chemistry and plants requirements. The concept of "buffer" as mentioned by idaho-gardner is very interesting as applied to soil chemistry.

I got into serious gardening within past three seasons. Started from GA red clay, with lots of redish rocks, stones. I got into internet and learned about ways to amend that red clay. I did all that very hard work, without buying any topsoil or compost from anywhere. I was told that I have to pay attention to soil PH.(potential Hydrogen), which I was familiar with from college chemistry. Then I checked the soil; PH was around 5.4. I was told (internet , info from PH meter manufacturers) That it was too low unless I wanted to grow just potatoes. WHAT TO DO?? "lime"! so I kept adding lime , but then I was told that it will take a year or so for that to work and bring that PH up. I also kep pouring lots of wood ash from my fireplace....
but despit all that low PH I managed to grow decent tomatoes, onions, squash, cucumbers, and all kinds of herbs.
Now, the soil PH in my garden is probably around 6.2. I did fine with PH=5.4 so I sould not worry about it. Some fellow gardener here in GW warned me "be careful, not to add too much wood ash it can raise the PH..". I was just getting scared right there (LOL). But right now, WHO CARESS about PH! forget all about it and unlearn what you have learned.
I am so relaxed now, not worrying abou this and that thechnical and scientific jargons. The nature is smarter than all of us.
Cyrus

Don't go tilling in pine straw.

Pine straw is acidic, but it's not very strong. If you have a legacy soil that's had decades of organic matter due to pine needles making up most of it, that's another thing.

Also, if the stuff is raw/uncomposted it will tie up nutrients, especially N, in your soil. It wouldn't hurt at all to use the stuff to cover your beds as a mulch, though. It will help acidify a soil a small amount over the course of a season.

Thanks. Great help. I do have pine straw that's been accumulating under about 20 pine tress for 15 years. I'll dig some up and. use it as a top dressing/mulch. Sounds like a slow and steady idea for a problem that's not so bad.

The U of Delaware suggested only adding nitrogen in the form of urea.

Scott

1-
"The U of Delaware suggested only adding nitrogen in the form of urea. " drscott.

Obviouly. Their test shows aboundance of P and K.
2-
" ..I do have pine straw that's been accumulating under about 20 pine tress for 15 years .." drscott.

Only the very top layer of the pine straw accumulated under trees are fresh and suitable for mulching. The rest can make an excellent soil amendment. Your soil being alkaline(PH =7.4?), adding that will not cause any problems. Most of my soil amendment came from the same source.