Well, for one, I do not think it is good to generalize.

I do not have a lick of clay in my soil here. And if I did not continue to add compost, manures, etc. regularly, I would be back to gravel and sand in no time.
Besides, why is compost itself, so high in potassium?

I thought it was phosphate that we had to be careful with--like triple super phosphate for roses or extra phosphate that is in the "bloom" fertilizers etc.

As was noted, generalizations don't necessaraily fit everyone's situation.

As for high potassium from compost, it's unlikely if the compost comes from the usual variety of various ingredients.

However, shifting the balance of ingredients with an abnormal amount of banana peels can potentially increase the potassium excessively.

My suggestion is that you obtain reliable local advice. Perhaps call the Master Gardeners at your county's Extension Service office to obtain information that relates to your region.

Then supplement that with a soil test from a professional laboratory -- the Master Gardeners can suggest one or more labs -- which will give you a baseline value for *your* soil in *your* garden.

I read that book, but it was a while ago. As I remember, the author said that potassium levels were high because the nitrogen and the phosphorus leached out (due to the rains we get), leaving the potassium more concentrated in the soil. Adding a 10-10-10 fertilizer would thus maintain the higher level of potassium because it is adding equally of all three.

As has been mentioned, you might want to have your soil tested. Much like temperature micro-climates, there's plenty of soil variability within the maritime NW.

I'm thinking you should ask this on the soils forum, because I'm thinking that this is going backwards.

I thought that it was the Potassium (K) that can leach out and that the Phosphorus(P)is the one that can build up.

Here is a link that might be useful: one resource-- but not PNW

Correct. Phosphorus doesn't leach. Potasium does leach, but far less than does nitrogen.

The benefits of adding compost far outweigh the potential downsides of something like too much potassium. Most soils around here need it badly, you just don't want to plant in pure 100 % compost. Mix it in a little.

I think Sam WA of the last post said it about just right.

The author may have a point, but the overall picture is imporatant.

For example, many sources say fertilizers are good for trees. True.

But, frequently, in windy PNW areas, the trees that blow over are the ones with big leaves and weak wood from fertilizing.

So the fertilizer was good for growth, but for durability, the fertilizer may not matter in many cases.

Many tid bits make sense when viewed only from a single aspect.

Comments appreciated. I know of no place other than Garden Web where a discussion like this can occur. Here are some of Solomon's comments, which prompted this posting (I'm quoting him not because I know enough to agree or disagree, but so that the information is available for discussion):

First, he generalizes that the Maritime Northwest has a fairly uniform geologic history, and that the soils throughout this region are generally similar in mineral content. So he doesn't encourage testing.

Then, on page 27: "the essence of our region's soil imbalance hinges on an overly high level of an otherwise useful mineral, potassium. Our soils usually have lot of potassium - maybe too much. I've studied the results of hundreds of soil tests performed by OSU and I have never seen a test showing a marked potassium deficiency - lots of other deficiencies, yes, but not of K"

Also on page 27: "the nutrients that provoke plants to become highly nutritious - calcium, magnesium, and phosphorus - are the ones most readily lost. I view this as a widespread regional mineral imbalance."

He goes on to say that because plants concentrate the potassium in the fiber and woody parts, and those are the main parts that are used in a lot of animal feeds (and therefore enter into manures) and composting, while other minerals are leached out in rain or removed in farm products, that we are artificially increasing the potassium in our soil while other components decline. So, he offers that the more compost we add to our gardens, the more we bulid up potassium relative to other elements.

The Clemson link above was really intereesting. In a way, it could be taken to support a contention that using a lot of plant stems in compost would increase the soil level of potassium where that compost is used. "Luxury consumption and leaching loss make it undesirable to try to build the potassium level above medium." It does state that potassium will leach into the clay layer - although, my soil is all basically clay layer... now amended with lots of compost.

Anyway, I'll keep watching for comments. For now, the fruit peels will still go into the compost.

The potassium added by compost is such a negligible amount, I really wouldn't worry about it. If you're concerned about the balance of calcium, magnesium, and phosphorous - then try adding some bone meal ( a great source of calcium and phosphorous). Epsom salts are a good way to add magnesium. OR try dolomite lime (magnesium and calcium). Soils in Western WA (and Oregon) are generally lacking in nitrogen as well, due to all the rainfall leaching it away. So be sure to add some of that in the spring.

The only time I wouldn't recommend adding compost is when planting trees and shrubs, at least into a hole. If your soil is halfway decent, just plant the trees into that, and use compost as a mulch. Compost added into a hole will encourage the tree to root into just the compost, and not into the surrounding soil.

Keep adding those fruit peels!

I don't think the soils are very similar.

Recently, I moved to southern Oregon, about 100 miles from the coast, after being in Portland, which was about 70 miles from the coast. That's not too much difference in terms of "maritime".

Anyway, the soil in east Medford is substantially different from what the clay soil in Portland was like.

Then next to Medford is Jacksonville, which has a different soil yet. In the hills south of Jacksonville, one yard can grow almost anything, while another will have excess boron from the wells - virtually neighbors.

So the soils are different and the well water is different in quite a few locations.

There appears to be much more diversity in southern Oregon, than up around Portland. But Vancouver, WA, across the Columbia seemed to have some very rocky areas - not sure about the nutrients.

I don't know if I'd say that everybody should have a soil test, but it doesn't seem that anyone could go wrong by getting a soil test considering how affordable they are.

In the situations quoted by Steve Solomon, the amount of potassium added by compost *wasn't* negligible. The compost was local, made from local vegetation, itself high in potassium, creating a concentration effect. I do have a part of my yard where the potassium levels are high, and it's been kind of frustrating to deal with.
I gave up trying to get GW advise on how to handle it, as I just got a lot of argument about how it couldn't possibly be true...it wasn't this forum, obviously.

I think you had the key written into the the question: your vegetables are doing great, ergo...your soil is fine.

I guess my concern was more for long term, adding compost year after year in the thought that you cant have too much "gardener's gold". I was taught that compost was the great equalizer - it would improve clay soils, improve sandy soils, make plants more disease resistant, balance predators & prey, etc. Then I read a book that claims this isn't true - that in the NW (which is why I posted in the NW forum), compost increases potassium at expense of other nutrients, and increases symphylans (which I never heard of before) to the point that nothing will grow. So I wondered about the long term effect of adding compost each year.

When I moved to this house 4 years ago, the soil was so hard that I couldn't dig in it - I had to soak, dig, soak, dig, etc. With addition of lots & lots of compost, from various sources, the tilth is incredibly improved. So I thought I was on the right track. And maybe I am. Or not?

Probably, I shouldnt have been reading so much. You are right - most of the the fruits & veggies were great last year. We'll see how they do in 2006.

Thanks for the comments;.

Sample soil and have it analyzed to get an idea what you have. This is not a one-time thing, nutrient content can change as time goes by.

Nature's way is for litter to fall on the ground and form a layer on the surface. When gardeners do this it is called mulching. This is the best approach for permanent plantings, rather than amending. Vegetables tend to be developed from short-lived plants native to disturbed sites, so it is more natural for those to be growing in cultivated, amended soils. In a recently disturbed natural site there might be organic litter buried beneath the surface as well, depending on what kind of disturbance it was.

Where do you usually send your soil samples for testing?

Try local Cooperative Extension office, for starters. There are also home test kits at garden centers, these at least tell you more than nothing. More sophisticated analysis purchased from testing lab not perfect either, but alot better than throwing on fertilizer or bulking up organic content without any such information at all.

"Last fall we collected soil samples from a local organic demonstration garden and sent them out for
nutrient analysis; this garden had recently experienced some soil and plant health problems. Every single
one of the sites that was tested came back with nutrient readings off the scale. In large capital letters the
report warned "DO NOT FERTILIZE THIS SOIL." The excessive addition of nutrient-rich compost to
this landscape contributed not only to plant health problems but to nutrient loading of adjacent natural
waters."

Here is a link that might be useful: Soil Amendments, Part III