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Aged Pine bark Fines as soil ammendment...

Posted by emyers 8 SC (My Page) on
Mon, Sep 8, 08 at 21:48

I have access to bulk "aged" pine bark "fines". While they are not technically composted, They have been aged for 1 year + in piles & kept moist & turned. It's also described as readily rewettable.

sizes of material are as follows:
5-8% greater than 1/2" (but less than 5/8"
25-31% less than 1/2"
64-71% less than 1/4"
Moisture content 25%

PH 4.5

Considering using it to add organic matter to my sandy soil by incorporating it into the soil, also possibly as a top dressing/mulch, also possibly as a mulch on my centipede lawn.

Would I need to be concerned about it tying up nitrogen since it has been aged for at least a year? How about it Lowering my already low 5.9PH w/ 7.75 buffer ph?

I've misplaced my notes but seem to remember it being low in nitrogen, very low in phosporous, and relatively high in potassium. My soil currently is low in potassium & high in phosphorous so was thinking this might be the ticket for me.

Any more thoughts on this stuff? Anyone with any experience?


Follow-Up Postings:

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RE: Aged Pine bark Fines as soil ammendment...

Top dressing, yes. Mixing it in, no.

If you want to mix it in, compost it first.


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RE: Aged Pine bark Fines as soil ammendment...

As a mulch they are fine, as a soil amendment no. Unless you add enough Nitrogen to offset the Carbon you are putting into the soil.


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RE: Aged Pine bark Fines as soil ammendment...

Just want to make sure I'm clear that they have been for all practical purposes, composted for a year plus.

How much nitrogen tie up could there be?

Any way to determine how much through soil testing and such?


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RE: Aged Pine bark Fines as soil ammendment...

If what you have is really pine and only bark (as opposed to the inner wood) you can mix it in with no concern for N immobilization.

Pine bark fines are a common ingredient in soil-less potting mixes because they do not immobilize N. Most wood products, yes; pine bark fines, no. Same for the bark of fir and hemlock.


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RE: Aged Pine bark Fines as soil ammendment...

I agree with justa. The BARK of conifers has a very high lignin content and will not contribute to nitrogen tie up.

I used such a product extensively when I lived in SC where there were supplies in close proximity. I used the fines making my own nursery, bonsai, and potting mediums as well as a fabulous soil amendment. Most nursery mixes are composed almost entirely of pine (or conifer) bark fines which have not been composted.


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RE: Aged Pine bark Fines as soil ammendment...

OK.
2 for and 2 against.
My how this stuff gets complicated.

Yes, it's pine BARK only.

Any more takes on this?

justaguy and rhizo-
Any idea how it will affect my 5.9 PH?

How much would you recommend incorporating into my sandy soil that currently has very little organic matter.

Any idea what would be better for my soil/ get the organic matter up in my garden quicker- growing and turning in a cover crop or incorporating the pine bark fines.

Could I, could it make sense, to incorporate pine bark fines in place of traditional compost that I make on site?

What if I were to bypass the traditional compost but use some combination of fresh cow manure (or possibly chicken manure) and the pine bark fines.

The fines are relatively easy and inexpensive for me to get, so if it could somehow be at least a partial substitute for traditional compost, it could make my life a little easier.

Any additional thoughts appreciated (that goes for everyone).


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RE: Aged Pine bark Fines as soil ammendment...

OK.
2 for and 2 against.

Not really. The 2 'against' are responding to the general idea of incorporating wood products into the soil. With few exceptions this will result in nitrogen immobilization, but the BARK of CONIFERS doesn't. It is simply an exception to the rule. You are good to go. Let me explain this in a different way. When we introduce wood to soil the wood generally decomposes pretty quickly. The bacteria decomposing it require nitrogen to continue breaking down the wood. This results in the bacteria taking up the N until the wood is composted at which point the N is released back into the soil. Conifer bark has high amounts of lignin which results in bacteria having a difficult time breaking it down. This slow rate of decomp is why N isn't tied up/immobilized. You saw this yourself with a pile left for a year moistened and turned, but it didn't compost.

Any idea how it will affect my 5.9 PH?

It isn't likely to affect it much. You will need to adjust your pH with convention means. That means either a ton of organic matter over years or a much smaller amount of lime. Please do not try to use lime to adjust soil pH by more than 1 point per year. This means add lime now to raise pH by 1 point and by this time next year the soil's pH will be roughly 6.9 which is close to ideal for most things (actually just a tad on the high side of optimal).

Any idea what would be better for my soil/ get the organic matter up in my garden quicker- growing and turning in a cover crop or incorporating the pine bark fines.

I would suggest both. Add the bark fines to increase the water retention of the sand soil now and add other organic matter to boost fertility and soil critter diversity. Pine bark fines bring little to the table in terms of nutrients, but will improve water retention (and nutrient retention) in a sandy soil.

What if I were to bypass the traditional compost but use some combination of fresh cow manure (or possibly chicken manure) and the pine bark fines.

Again, the bark fines are a longer lasting amendment than compost or manures, but they add little in the way of nutrients. I would add both to get both benefits in a sand based soil.


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RE: Aged Pine bark Fines as soil ammendment...

Don't be afraid to till it into the soil. Yes it will use some nitrogen to decompose, and yes it is acidic, so add some blood meal, feather meal, alfalfa meal, etc. to give it a nitrogen boost, and some lime to add some lime to deal with the acidity. The organic matter will do much to improve the tilth of the soil, and it will do a lot more good that harm. Gi for it!

Ron
The Garden Guy
http://www.TheGardenGuy.com
Come on over for a visit!


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RE: Aged Pine bark Fines as soil ammendment...

  • Posted by dicot Los Angeles (My Page) on
    Tue, Sep 9, 08 at 20:42

When I use fine wood products as top dressing, even slightly aged, I sometimes have clumping problems and find dead zones of anaerobic decomposition. If it was me, I'd mix it 50/50 with lawn clippings, use it as surface mulch then come back in two months and mix it and some solid, slow decomposing P & K organic supplements like bone meal and wood ash 6-12 inches deep.


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RE: Aged Pine bark Fines as soil ammendment...

When I use fine wood products

This is different. Many people and nurseries use a potting mix based upon pine bark fines. It doesn't clump or tie up N.


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RE: Aged Pine bark Fines as soil ammendment...

Picking up trailer load of pine bark fines this morning to incorporate into the garden.

For my sandy soil, looking for recommendations as to how much to incorporate and how deep.

Originally was thinking I'd aerate/break up soil with a spading fork (not turning over) down to about 12", then come back and till in only to about the top 4", incorporating say a 2" layer of pine bark fines. I've gotten concerned about bringing too much stuff up from the bottom (more hardpacked and clayey material down there).

Now I'm wondering if maybe it could be beneficial to bring up some of the more clayey material to the surface?

If I were to till up a full 8" for this initial season, how much pine bark fines would you add/till in, at a max and minimum.

If I tilled in 4" of pine bark fines down to 8" would that be too much?


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RE: Aged Pine bark Fines as soil ammendment...

The Soil Food Web, the bacteria and fungi that work to feed your plants in the soil, function in the top 6 inches of soil because that is about as deep as air will normally infiltrate the soil, easily. Much below that depth earthworms are the primary workers. Concentrate on the top 6 inches of your soil and everything else will fall into place. Tilling bark into soil creates more problems than that will solve. I would use the bark fines as a mulch only, and would not work them into the soil.


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RE: Aged Pine bark Fines as soil ammendment...

Tilling bark into soil creates more problems than that will solve.

After reading posts in this thread what problem do you see occurring if pine bark fines are incorporated into the soil?


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RE: Aged Pine bark Fines as soil ammendment...

OK. I tilled about 2" of aged fines into the top ballpark 8" of soil. Now I'm thinking about using some additional fines as a mulch in my garden.... say another inch or two.
If I do this, do I run the risk of of getting too much of the stuff into my soil? Any problem with this being a biennial ritual?


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RE: Aged Pine bark Fines as soil ammendment...

So at this point 25% of your growing depth is pine bark fines? That seems reasonable to me. Using it as a mulch won't hurt anything, but it can be very hydrophobic meaning once it goes dry it resists rewetting.

I have used it around a tree and didn't care for it. In this case the water runoff from rains was able to pick it up and wash it away from the tree because when dry it doesn't take up water quickly and it is pretty lightweight. Just something to keep in mind. If you have it contained in framed raised beds or something it shouldn't be an issue.


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RE: Aged Pine bark Fines as soil ammendment...

Makes sense on the hydrophobic/rewetting thing. Didn't realize that the fines were that difficult to rewet.
If I do decide to put them down, recognizing that they are difficult to rewet, does that mean that my garden will be more difficult to water, or will the water just kind of bypass the fines and work itself into the ground?
I'm understanding that the bark etc is likely to dry out but, it still will be productive as far as holding moisture in the soil beneath correct?

All this being said, the whole runoff thing certainly is an issue. I see your point.

If you had the choice of using shredded leaves vs pine bark fines, which would you choose? Wouldn't the shredded leaves also be hydrophobic to a degree? Subject to drying out?

Thanks.


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RE: Aged Pine bark Fines as soil ammendment...

The fines won't make getting water to the soil below more difficult, it will just run right through. It will do a good job of limiting evaporation.

Between the fines and shredded leaves I would prefer the fines, but that is only because I have a windy location and the one time I used shredded leaves as a mulch they all ended up in my neighbor's yards and I didn't realize until I saw a neighbor raking them off his lawn. He gave them back to me and I put them in the compost pile instead of back on the garden. It was kind of embarrassing.


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RE: Aged Pine bark Fines as soil ammendment...

Great. That answers a LOT of questions for me. I think I'm going to give them a shot.

Any idea what would happen if I tried to rake in dwarf white clover seed into the fines in about a month (as long as I kept it moist). Do you think the roots would penetrate 2" or so to get down to the soil below? Anything that you could dream up that I might try this idea of direct seeding a cover crop into a relatively thin mulch?


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RE: Aged Pine bark Fines as soil ammendment...

I have used an organic blended medium by a farm that had pine bark in it and it was the best I have ever used. If you are worried about nitrogen then you could blend in manure that is high in N. I use sul-po-mag for potassium it usually rates around 0-0-25. To buffer your PH and make it neutral you can use garden lime or dolomitic limestone. Espoma makes a good garden lime. I don't see how the pine bark would contribute to a deficiency because once you mix it in the soil it will age more.


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RE: Aged Pine bark Fines as soil ammendment...

I did'nt have the time to read all the "wisdom" against pine bark fines. The best blueberries in the world are grown in straight pine bark fines. No dirt, no sand, no nada, just straight pine bark fines. Someone will say, that's because blueberry is an acid lover. Duh. But down here in Florida, all nurseries use compost and pine bark fine blend for potted plants and soil replacement for all plants.


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RE: Aged Pine bark Fines as soil ammendment...

Trust me on this, Kimmsr gives really good, true advice. I already used pine bark to help my clay soil, sure it really works to make a faster draining soil. The fact is- mulching with compost which feeds the micro life in the soil; makes a loose soil. We may be looking at the bark as a quik fix, when building the soil using compost will creats a long tearm rich, yet loose soil. The more activity of soil organisms will make an easy to grow in soil. I used to install plants and of course we did not have time to build the soil of the location the plants were being planted. The specific landscaper I worked with liked using sand/peat to mix with the soil to loosen it up- a big no no if you ask me as sand just made it heavy and was too fine. I suggested we used mushroom compost that we could get by the truck load for cheap, it worked really great. The landscaper showed me some pruning techniques, and I helped them understand they never have to haul sand ever again!!

So, really in the long run- you could add compost/leaves/ect to any native soil type and it will improve over time to the "perfect soil".


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