Just wondering if you have a souce for BARK fines, instead of saw dust. A double or triple ground bark is pretty good stuff.

kennesaw,

Thanks for sharing your experience.

How much is 5 tons of sawdust by volume?
About how many inches of sawdust did you till in?
And how deeply did you till it in?
What did you use to till it in, rototiller?

Let us know how it performs after next summer's season.

Thanks for sharing that.

A test of my soil, a clay loam, earlier this year came with a recommendation to add 6-8 yd3 of redwood sawdust/1000 ft2. I've been using trench composting instead to boost OM but I also regularly apply horse stable waste, which is mostly sawdust. I notice that it dramatically improves the tilth of my soil, reducing the large clods and stickiness. If I don't add N to the soil at the same time, I get almost no weeds in areas I've added sawdust, presumably because the microorganisms that are digesting the wood have tied up all of the N.

I've also read that decomposed wood produces the most stable type of humus in soil.

What is your plan to maintain levels of OM in your soil? Cover cropping? Compost? More sawdust or other amendments?

Tell us in two years when all the wood had truly decomposed what you soil is like.
I am really curious, as I have heavy black gumbo and eventually it often, after time, returns to plain old heavy black gumbo in time no matter what I put in it.

Wood products are the best to improve the soil. Most bang for your buck. You are sitting pretty and glad you didn't listen to all the nannies about nitrogen. And it was SIMPLE, you didn't have to go thru all the hocus-pocus like people will tell you that you have to. It all rots in the end. It will continue to get better as time goes on. Wish I could be so lucky.

Did you plow it in?
How deep did you work it in?
What is you subsoil?

Losing a years production might be significant to some so that would be a consideration if someone else was trying to emulate this experiment.

As far as I'm aware, sawdust doesn't contain much in the way of nutrients. Making the soil easier to work with certainly has benefits but I'd bet a good quality compost would do that and more.

Lloyd

Thanks for sharing your 'experiment' with sawdust.

I think it's important to say that all sawdusts are not equal. Results likely depend on type of wood and age of the sawdust.

I've used free sawdust for years as the brown in my compost used exclusively as mulch. Source is a small mill that uses mostly pine, but also spruce and fir.

I'm trying a different experiment this year as found a source of free bark shavings from a log home builder (only had to pay trucking). This material was already beginning to decompose - parts of it looked like soil and it heated when left in a pile. I've not tilled it in but have heavily mulched my perennial garden with it. Will watch to see if there is nitrogen deficiency but expect there will not be. I use alfalfa tea as fertilizer anyhow so that should prevent any problems.

Sawdust makes a wonderful mulch and many commercial berry producers use it. Good to hear it can also be tilled in to improve clay soil. In many areas sawdust is easier to find than a quality compost so using it to lighten clay soil and adding nitrogen, smaller amounts of compost, and fertilizer if necessary seems to be a good option.

Answers to your questions:

How much is 5 tons of sawdust by volume? - Answer: 10 full-size pickup truck loads of bagged sawdust.

About how many inches of sawdust did you till in? Answer: About 4 inches.

And how deeply did you till it in? - Answer: About 7-8 inches.

What did you use to till it in, rototiller? � Answer: 9-hp rear tine rototiller.

What is your plan to maintain levels of OM in your soil? Cover cropping? Compost? More sawdust or other amendments? - Answer: Whatever OM is available, grass clippings, leaves, sawdust etc., to be used for mulching only, to be tilled in at the end of the growing season.

What is you subsoil? � Answer: Red clay. The garden is on a sight to moderate slope, so drainage is not an issue. The grass surrounding the garden filters out any soil from the runoff during heavy rains. .

Making the soil easier to work with certainly has benefits but I'd bet a good quality compost would do that and more. - Answer: Yes good compost would be "best", but that was not an option. I did not want 5 ton sawdust compost pile in my yard, nor was I willing to pay several hundred dollars to purchase compost.

What was the cost for the nitrogen?

The only real difference between incorporating sawdust and peat in your soil is that the sawdust has a greater surface area, so it will break down faster, and draw nitrogen out of the soil proportionally. Balancing added nitrogen to account for the decomposers is going to be tricky if you're growing crops at the same time. A year later, you're golden.

I love it when somebody says use a "good quality compost" as if everyone has access to it and can afford it. I don't think kennesaw was expecting much. When you have heavy clay the last thing to worry about is Nutrients. You need to improve the texture or nutrients are a moot point. If the plants die because they sit in soggy soil then there's no need for nutrients! Around here the closest you get to "compost" is "landscape mix"- ground up yard waste that has sit for a while. The vast majority of initial N depletion happens in the first few months and goes downhill from there. Mulching with any organic matter without digging it in will not deplete the N.

I don't think anyone here said "use a good quality compost".

Lloyd

Thanks for sharing your findings. A few years ago, I got a few bags of sawdust mixed with chicken manure. One of them went into a tiny little flower bed, quite a large amount for such a small bed. Every year since, I have been delighted to plunge a spade into the bed each spring! The spade almost disappears because the soil is so light and friable and very easy to dig. given the clay soil everywhere else on the property and the hardness of it, this little bed gives me pleasure. I expect that the combo of sawdust and chicken poo is similar to your sawdust and nitrogen.

This is interesting. Kennesaw said that 4 inches of sawdust was mixed into the soil for 7 to 8 inches. I too have found that 4 inches of local sphagnum peat moss does a similar loosening job on clayish soils....so very nice to work with. The peat has no delay effect as it is fairly inert, and acts mainly as a soil conditioner.

pt03, I think you have a memory problem.

#sets up popcorn concession# and sets up lawn chairs.

there's no reason you both can't be wrong. no one said use...but some one suggested similar or better results from.

my favorite part around. anyone for lemonade?

What was the cost for the nitrogen? Answer: $20 dollars per 50 lb. bag of urea (46% nitrogen). I used 2 baqs over the spring and summer.

For sure my memory is not what it used to be, but in this instance I don't think it is failing me quite yet. I do think some people are having a comprehension problem though. Having said that, I'm willing to stand corrected if a quote could be found.

Lloyd

Oh my, Lloyd, here you said:

As far as I'm aware, sawdust doesn't contain much in the way of nutrients. Making the soil easier to work with certainly has benefits but I'd bet a good quality compost would do that and more.

Lloyd
Remember that? The inference is clear, I don't see how it could be otherwise. Cut and pasted directly from your post on Mon, Oct 29, 12 at 19:35

I'll take my response off line.

Good Lord, the whole Northeast just got bombed back to the stone age, and we're arguing about compost? :-D

He started it! ;-)

Lloyd

LOL guys, let's leave the picky, picky to women where it belongs! ;D LOLOL Even ignorant little me has used the term "good quality compost" a few times. I doubt there is anyone who has been on this forum any length of time who is not aware there are various qualities of compost. Even clay soil does not deserve a compost made with materials saturated with chemicals that will harm their plants. That might be termed 'bad quality compost'.

We all need to keep in mind that we don't all have access to abundant amounts of compost, sawdust, or any one particular amendment. I consider myself fortunate that I live in an area where lumbering is big business and compost is free for the shoveling. Compost I'd have to buy and it's not inexpensive.

This thread has been an eye opener to me and I'm wondering if I should begin another project using sawdust to amend a larger area. Thanks kennesaw (I think!). I'm curious to know if you had to pay for the sawdust you used and if so what was the cost?

AND please, please, please, let us not turn this thread into another peat bashing thread. There are enough of those around.

Who is this Pete Moss and why is he getting bashed?

Who is Pete? I think he is that rascal that owns/leases about 270 million acres in Canada. Little Pete lives near me...about 10 acres.

I think Pete gets bashed because it's the pc thing to do.

I feel kind of lousy for responding to tox with humour, there is nothing funny about this storm and it was inappropriate to do so. Sorry gang.

Lloyd

In response to the question about how much I paid for the sawdust, I paid $1.00 for each 50-60 lb. bag. The bagged sawdust was also easier to transport the 200 feet from my pickup truck to the garden than bulk materials. It was very easy to blow away any sawdust residue off my pickup truck and driveway using a leaf blower. Most mulches and composts contain 50% or more moisture. Dry sawdust probably contains about 10% moisture. For me it was a very cost-effective, time-efficient method of improving my garden soil. Of course, sawdust amending would not work as well in a dry or cold climate, where the decomposition would be much slower.

I'm interested in the comment that many commercial berry growers use sawdust as mulch. Can you elaborate? Hardwood, softwood, how finely ground (really a dust? or more like chips/ground?).

I have access to very fine hardwood (mostly maple, some cherry) sawdust from furniture shop, I tried it as soil amendment in past and even mixed with N source (tested OK) my plants did not do well in that bed. Too fine to use as mulch (blows away when dry, repels water when wet) or in compost (tends to sift down through pile and settle). I do have a few raised beds (app 1ft x 25ft each) of brambles, had mulched with decomposed wood chips in spring but those are fully decomposed now, covered roots with burlap during recent freeze but I'm looking for a good winter mulch to put over/under burlap now. Was thinking shredded maple/oak leaves.

Gee Guys, I write from downunder - Blue Mountains, west of Sydney. I am ex-UK. They call me a pommie winger. In England they would call you "old Farts" or even "old Tarts". Me, I reckon you are a pack of Shielas. That said, I enjoyed your contributions - nothing like a beer and a good barney.
O.K. exactly what do you call hardwood. I know you have eucalyptus in California. With old eucalyptus floor boards - you have to drill before you can knock a nail in. River red gum is used as a bearing plate under footings and will last for ever; say 2 or 3 generations at least in poor swampy ground. Untreated iron bark utlity poles are good for 30+ years - even the white ants have a hard time to get a meal. Aussie Oak some might class as hardwood; English Oak is debatable - but neither are true hardwood.
Mulching with hardwood chips - 2 to 3 years, dig em in and no problem. I left a truck load of harwood chips about 5 or 6 years - grass grew over them after they had settled. I eventually dug them in. So instead of gravel, I have woody, leafy bits to give the soil an open workable texture. I am only a weekend, fair enough is good enough. Here we use a potting mix which is "quality" soil with very small wood and bark chips.
Keep smiling, Regards to You All; Bill the stirer.

kennesaw,
Thanks again.

This is the info I'm adding to my gardening files:

46 lbs of nitrogen over 3,000 sq ft was not enough to overcome nitrogen lockup of 4" of sawdust dug in 8".
But second season crop didn't need fertilizer.

Someday I may move and have a big garden like yours and this info would be useful.

cheers

I have just bought a house that had had a pine tree removed leaving a deep 3-6" depth of sawdust over a 20 X 20 area. Is there anything I can do to help this sawdust decompose? Should I be trying to till it into my soil?

I hate the idea of just trying scrape it all up and cart it away.

Thanks.

Use it as mulch, mix it into your compost batch, till it in, just don't cart it away!:)

Jane, is it the chips from the chainsaws that you have? That is quite a bit more coarse than what is typically meant by saw "dust", which is the debris from a circular saw of some kind.

I don't know for sure since this is inherited when I bought the house, but it looks similar to what I've seen before from stump grinding - so pretty fine and finer than a standard chipper would produce.

How long has it been on the ground? Weeks, months or years?

I was a little surprised to read above that the only difference between peat and sawdust is the larger surface area of sawdust. Is there really no other difference (to the soil) between these two amendments?

Peat is decomposed about as far as it can go already, whereas sawdust is just starting out and will have to go through a fungal decomposition stage which breaks up the fibers and cells, followed by bacterial decomposition. In the end they will both become soil organic matter (humus). Peat will have less of a disruptive effect on the soil in the short term, whereas sawdust will tie up nitrogen while it decomposes.

I think the point was that they will both have similar long term effects on soil texture and tilth.

How much sawdustcoculd a healthy soil accept annually without adversely impacting production? Sure, I understand that ANY amount will lower N somewhat, but could one get away with , say, a 1" layer of hardwood shavings (as a nitriogen sponge) in the fall, and have the soil return to N levels that would support 'reasonable' growth by the growing season?

What about repeating this process annually? Would long term N release from previous years' applications compensate to a degree for N reductions brought about by fresh applicaitons?

How sawdust, or any other woody material, would affect soil Nitrogen depends on whether you till it in or just lay it on the surface. High carbon material laid on the soil surface, as a mulch, has a negligible affect on available soil Nitrogen whereas the same high carbon material tilled into the soil can cause any plants growing there to have Nitrogen deficiencies.

kimmq is kimmsr

I agree that mulching is less disruptive (of N depletion) than tilling in, but was wondering roughly what amount I could till in without creating havoc with next growing season. My default amendment is seaweed, and I put on a 2"-4" layer each winter, let it winter over on top of the soil, then spade it in each spring. It seems to work; if anything, I seem a little heavy on N for crops such as potatoes and tomatoes. So I'm wondering how much sawdust I could add without causing a huge disruption. I have access to hardwood (woodshop) shavings, and in the past have used them largely as mulch for the raspberry patch.

It's a matter of timescale. In situ composting of high carbon material will cause nitrogen depletion. But once it is completely composted, and the soil bacteria take over, nitrification begins and the soil nitrogen is replenished. That happens slowly, and happens best when the soil is well aerated. So tilling in sawdust before you plant is a bad idea. Tilling it in the season before, and retilling a month or so later, should work fine.

I routinely till in uncomposted shredded leaves in the fall and, by spring, the bed is in good shape. Pre-planting beds are only amended with compost, however.

You might want to blend in some sawdust/shavings with the seaweed and lay it on together. Wood is a super brown, C:N in the 250-500 range. I would think if the seaweed is wet, a balanced mix for compost is probably going to be less than an inch for 2-4" of seaweed. But you can probably use more than that since you're letting it overwinter. You might try 1/2" and see how it does.

Put on an inch of mostly jointer shavings on (with) my usual 4" of eelgrass. Planning to turn it all under in spring, and will let you know what happens.

josko, always wanted to try composting eel grass so I'd be interested to see how it goes for you. I used it for mulch one summer and it didn't seem to break down at all. Probably has great micro/macro nutrient levels for the garden.

Harry

I do 4"-6" of eelgrass on my veggie garden each year. Typically put it on in late fall and spade it in in the spring. In summertime I find little patches of progressively more fragile clumps, and they're typically gone by fall. Garden's been doing great, although I've learned to apply some N-blockers, such as sawdust when planting things that don't want too much N.

After storm Sandy, I did a large compost pile of eelgrass (that the storm dumped on our beach), leaves and fish scrap that turned out very well. It should be accessible by an 'eelgrass' search here.

I REALLY REALLY appreciate you posting this. I did the calculations for my 1/3 acre and what you did nearly parallels my current labors.

My garden yields were pitiful and after a rain the soil looks like it salt caps and hardens to the point that many soft plants have a very hard time penetrating the surface. I've done MANY things over the past several years, including cover crops, and nothing has worked. Now desperate problems create desperate and difficult solutions.

Different that you, I'm using about double the Urea which was recommended based on a University of Idaho publication:

http://www.extension.uidaho.edu/nursery/Extension%20Publications/Using%20bark%20and%20Sawdust%20for%20Mulches,%20Soil%20Amendments%20and%20Potting%20Mixes%20-CIS%20858.pdf

Our soil pH is a bit low (acidic) and because of that I'm adding an additional 3600 lbs of pellet lime (per acre). Weed's are not a serious issue but I use plastic film mulch and Tee tape (drip tape) which will help decompose the rough-cut sawdust, keep the urea/fertilizers in-place, warm the soil, keeps the vegetables clean, and naturally does work to keep natural grasses/weeds from spreading out of control.

Again, thanks. This was encouraging and I expect great results.

Please keep us posted on your progress throughout the growing season!