using manure to accelerate breakdown of wood chip mulch

Can I apply a thin layer of raw horse manure on top of a thick layer of wood chip mulch to accelerate the breakdown of the mulch into compost?

I realize that raw horse manure is considered too hot to be applied directly to soil. Would this recommendation also apply if it was applied to a carbon rich layer such as wood chips?

Hi P Mohan.  You ask a great question.

I think the short answer is that fresh manure will help break down wood chips through bacterial decomposition.  It may still take some time to break the wood chips down, but it will eventually happen.

If your goal is to dispose of manure in a practical way, then this is a great option.

If your goal is to break down wood chips, there is another option worth considering—use fungal decomposition by inoculating with an aggressive fungal strain.  Personally, I use this approach to break down wood chips using Wine Cap mushrooms.

Even better though would be to incorporate both techniques in separate beds and then combine the two for a final product.

If you are interested, I can give a few pointers.

Eric

If the goal is to accelerate the breakdown of the wood chips I feel that an easy solution would be to add compost tea on top of the wood chips periodically.

The goal is indeed to accelerate the breakdown of the wood chips while providing complete nutrition for the fruit trees. I have few fruit trees in the backyard that I don't really fertilize explicitly (organic or chemical). When I purchased the property it was just grass around the trees. Over the last 3 years I have been layering on wood chip and I think that has had a marked improvement on the soil life. But given how productive the trees are, I am not sure how to supplement the soil with the lost nutrients.

Would inoculating with fungi generate compost that is generally nitrogen poor, considering that the wood chip is probably carbon? Or perhaps the wood chips still have a macronutrient ratio that is appropriate?

Also you mention separate beds for the fungal and bacterial action. Is this because using both on the same bed with leg to competition between the two resulting in a suboptimal setup?

Anne Miller wrote:If the goal is to accelerate the breakdown of the wood chips I feel that an easy solution would be to add compost tea on top of the wood chips periodically.

Hello Anne, how would compost tea help? My naive understanding is that the tea temporarily accelerates the microbial life when the compost is made into the tea. This is presumably primarily bacterial. Say the compost tea does saturate the woodchips, would it still be effective considering that the bacteria need a nitrogen source to breakdown the chips? Perhaps I am approaching the objective incorrectly. I hypothesized that the reason for the slow mulch breakdown is a lack of nitrogen rather than a lack of microbes.

I only have anecdotal advice when it comes to this, but potentially positive!

I had 25 yards of woodchips sitting on my lawn this summer that I by hand moved. I am not some lumberjack of a man, so this was a very slow process that helped me observe a few things.

Observation 1
Fresh Compost can be fed wood chips.

I had some dairy manure/chip compost delivered that was still fresh and wet. This was plopped right next to my woodchip pile and over time they intermingled. I was pleased because the woodchips helped dry out some wet manure clots and in turn process down. This worked out for me due to the long time I had but I did notice a faster process.


Observation 2
A big pile of chips with fungus creates HEAT.

I on purpose inoculated part of my chip pile with Winecaps, but I also knew an elm that got chopped into the pile was half rotted and full of mycelium on its own.

I dug maybe.... two feet into the pile and ended up getting a burst of steam and fungus coming out. You could put your hand close to it and it felt like an oven! It was fines on the inside, with a bit of moisture, but the chips were degrading fast! I made use of it, but I made sure to wear a N95 respirator because I didn't want to be inhaling all that junk.

I have put the fungus based chips on my new fruit trees and they are doing well. I'm not sure if I have the correct scientific amounts of food for them, but I'm going to let them tell me if they are having issues. I hope this might help?

I made a bunch of "beds" that were about 4" of wood chips and then 2" of say 25% composted horse manure (mostly fresh is what I am getting at) 3 years ago. They do break down much faster when mixed in with the manure. I had pretty good results after 9 months. I never really grew anything in these beds, they are primarily a sort of erosion control. I mean weeds grow great in them I just haven't populated them with the planned berries and squashes that I plan to. Kale is all over in them, for what it's worth.

If you want soil production. Eric Hansen  from the first reply is your man. I say that as someone who has been meaning to implement his wine cap setup for YEARS.... I got a big load of chips finally this spring. But I had to spread them around to fight the mud!

If you have nitrogen and carbon laying about it will break down a heck of a lot faster than either on their own. Wood chips are like 99.9% carbon, so it's adding nitrogen that helps.

I've actually found that a pile (like a cubic yard or two) of wood chips can accept *a lot* of nitrogen (table scraps, foot waste) and just turn into compost. No smell, no mess. It's the easiest way I know to compost. Just dig a hole into the chips, add green matter, close up hole, do it again.

P Mohan,

Bacterially decomposed wood chips might be higher in N, but I no longer look at my mulch as a source of N.  I have been using Wine Cap Mushrooms as the primary agent for decomposing wood chips for several years and they magically make the wood chips into highly fertile material.  Truth be told, I no longer care much about the chemistry side of gardening (or growing an orchard).  Instead I look at the biological side.  My basic assumption is that if the biology is there in the soil, then the chemistry will take care of itself.  If you decompose chips with mushrooms (and this can happen very quickly), the appropriate bacteria will eventually make their way into the remaining chips as well.

The reason I would separate the two isn't so much for competition purposes--they actually can help each other quite will--but rather bacterial decomposition and fungal decomposition is typically done in two different fashions.  Bacterial decomposition should be turned several times whereas fungal colonies grow best if not terribly disturbed.  If you do use fungi to decompose the wood chips, then adding in some manure will actually help as the bacteria are symbiotic with the fungal strains.  Also, the manure will contain some N that the fungi will want to get.

Either way, you could get a good, fertile mulch out of those wood chips.  For my purposes, I might be tempted to make a little ring of mulch, mix in some fungal spawn and then sit back and watch the fungi break down the wood without any need for you to lift a finger.

Eric

Having the wood chips moist will help break them down, similar to the suggestion about peeing on them.

Here are a couple of threads that might help:

https://permies.com/t/140113/wood-chips

https://permies.com/t/54471/composting/concepts-compost-tea-doesn-sense

Eric,

Do you have a preferred source for wine cap spawn? I would assume that once you get some colonized, you probably wouldn’t need to keep buying spawn.

Scott,

I like to source my Wine Cap spawn from Field&Forest.net.  They are an excellent, knowledgeable source of all sorts of mushroom spawn.  I originally hoped that once I got my spawn started that I would no longer need to by any more.  It turns out that getting spawn to continuously self-propagate is a bit tricky as it requires some maintenance and timing that I just don't have the time to do at the moment.  Now I have successfully used chunks of infused wood chips (like a fist sized clump) to transplant spawn, but I find that I need to get it at the right time in the growth cycle.  I have a couple of beds that need to be reconstituted and my technique for that will be to inoculate the chips and wait for mushrooms to grow (this is easy).  But the next time I harvest the mushrooms I plan on harvesting the individual bases of the mushrooms and transplanting them into new wood chips.  Though I have not tries this in the past, from what I understand the fungi grows quickly from the established base.  I will let everyone know how this goes once I try it.

If you or anyone else is wanting more pointers on how to grow your own mushrooms, I suggest this thread HERE:

https://permies.com/t/82798/composting/composting-wood-chips-chicken-litter

This is my long-running account of my own experiences with Wine Caps, starting with me being a complete neophyte up to having some degree of competency today.

Eric

I make circular enclosures for my chopped up leaves. Last year, mid ‘22, I emptied the leaf mold from one of them, and tried an experiment.
I layered woodchips and heavy stemmy stuff like wild turnip stalks, corn cobs and stalks, woody prunings, etc, stuff that was too coarse for my compost piles that I did not feel like chopping up, in layers 4 or 6 inches think. Followed with an inch or two of manure from the horse stables down the road. (Jose, uses zero chems on his pastures and hayfields)

Got it up to about 3 1/2 feet deep, and dumped some loose leaves on top to keep the manure from losing nitrogen to the atmosphere.

So a few weeks ago, before the snow came, I was building a couple of new hugel beds, and wishing I had more soil to bury the wood, so I took a look in my woodchip/ manure bin. The leaves on top were unchanged, but the rest was incredible. Rich, black humus, with lots of fungal strands running all through it.

Of course, I now have two similar bins started, and plan on a lot more.

So to answer your question, yes. Do it.

We bed our milk cows with wood chips. We clean the stalls once a week. The half and half manure and chips composts down quite rapidly, and is great for the soil.