Nutrients, especially nitrogen, in mushroom compost

Hello,

So if anyone has followed my posts you might remember that I have a major wine cap mushroom compost project in the workings.  My bed is about 6’x15’ by 1’ deep.  The chips were inoculated about 1 year ago and are showing real signs of decomposing to the point where I am going to plant in them this season. Plants like tomatoes will be in fertile holes, but some plants I would like to seed direct into the compost.  

I am wondering what the “soil” nutrients are likely to be.  I am especially thinking of nitrogen.  Do the wine caps fix any degree of nitrogen?  The chips are from autumn olive I chipped myself.  I have no problem bringing in fertility if I have to, and will likely add some dilute urine if it would be helpful.

Crops I am considering for direct seeding include peas, beans, romaine lettuce, spinach potatoes, sweet  potatoes, onions and radishes.

If I had to plant these crops into little “fertile” trenches, this would be acceptable.  I have no significant supplies of finished compost, but I do have a pile of rabbit litter.

Thanks in advance and I look forward to your responses.

Eric

Hey Eric!

Those beans and peas are both legumes and have the ability to "fix" their own nitrogen from the atmosphere, and don't need any extra nitrogen. As for the other crops, I suggest sowing them then just observe, and if symptoms of nitrogen deficiency arise, supplement with a light dressing of the rabbit litter. Rabbit manure is pretty rich with nitrogen, and too much could do more harm than good, especially with tiny newly sprouted plants. It's always going to be easier to add more rabbit manure than it is to undo accidentally  adding too much.

Hey James, thanks for the reply,

Yep, I am planting those legumes for a reason.  I might not have been clear, but I was wondering if the mushrooms somehow fixed any of their own nitrogen.  I have a bunch of worm castings laying around so I might add some of those with my other crops, and I am not above getting a couple of bags of topsoil and manure to make little fertile trenches if this would work.  But my focus is on being self sufficient in terms of nutrients.

Hopefully, with some luck and cover crops I will have my nitrogen needs fulfilled by the end of the year.

Anyway, thanks for the reply,

Eric

I second what James posted, also don't forget that your urine is also a great source for Nitrogen when it is diluted 10 to 1.

Fungi rarely fixate any nitrogen, mostly they are going to act as filters for most minerals.
They will take in what they need but don't form symbiotic relations with rhizobacteria species.
Also, keep in mind that the fungi presence will influence the bean and pea rhizobacteria to give up some of their nitrogen stores to the fungi, the excess, un used by the fungi will be available for other plants use.

Redhawk

Redhawk,

Thanks for the response.  Those peas and beans are no accident, I am fully planning on making use of their ability to fix nitrogen.  I do have two questions though.  Firstly, I am planting legumes for their obvious potential.  Is there some other legume that grows fast, fixes more nitrogen than peas and beans and is also easy to kill by the time I am actually ready to plant a food crop later in the season?

Secondly, what are phosphorus and potassium likely to be like in said compost?  Should I buy in some bone meal, rock phosphate, granite dust and greensand or should it be fine on its own?

I just checked the bed yesterday and about 2 inches below the surface the chips are decomposing quickly.

Thanks for your input,

Eric

Most likely the P and K will be within the tolerance lines, if you start seeing bean leaves with browning edges, then add some bone meal and green sand and see if those help the plants recover.

I like the fast decomp of the chips, that means the biosphere is really healthy.

Redhawk

Eric,

Of course you have already heard from the guru, but on the winecap front, I have had much better success with spawn/chips placed with grass coming through them, so less than 12", maybe 5-6 inches deep, essentially expanded in place. I am told that the stropharia like to be associated with roots, and the patch that did best had some tall grass that poked through. My inoculation attempts of wood chip piles have not been as successful, I am not sure if they need some additional nutrition to prevent takeover of the pile by LBMs. I think your setup is more likely to be successful because of the autumn olive chips though- essentially in the pile you are expanding the spawn, and it seems straight chips are not sufficient based on my failure. Hopefully if people are reading your post they can avoid my mistake!

Redhawk,

Thanks for chiming in and taking an interest in my wood chip/mushroom compost project.  Instinct told me that the wood chip compost would likely be good for P and K values, but if I see signs of deficiency, I will break out the greensand and bone meal.  I always appreciate your sage input to my projects.

TJ,

Thanks for the response,

This last weekend I went out to my main chip/mushroom bed from last year and planted about 300 inoculated peas.  I simply mixed the peas in a bag with the dry inoculate, shook, and then pushed the little peas into the "soil" about an inch or so, and after planting the peas I sprinkled the inoculate over the bed.  Although I have not had any real mushrooms appear, my wood chips have plenty of mycelia growing through them, and the whole pile is like a big spongy mat, and not like a pile of individual chips.  In numerous places, my fingers easily broke apart soft chips that were barely strong enough to hold themselves together and the chips themselves were innervated with little white strands of mycelia.  This bed is about 12" thick, thicker than what you suggest, but the effects of the fungal inoculation are clear.  The bed is supported (barely) by old oak and hickory logs.  I stepped on one of the logs to reach in to plant a pea and the log absolutely crumbled under the weight of my foot, so there is quite a bit of rot taking place.  Whether or not this log rotted from wine cap mycelia or some other form of rot I can not determine, but I expect that this is the last year I will be able to rely on those logs to support my bed.  

Additionally, and perhaps supporting your assertion about the ideal depth of the chips, I did grow tomatoes in this bed last summer by making fertile holes of a manure/topsoil combination,  I am pretty certain that the tomato roots did not limit themselves to the dimensions of the fertile hole, and thus the wine caps likely had roots with which to interact.  I have also heard that wine caps like to have some interaction with soil, and perhaps the soil from the fertile holes enhanced their growth.  With luck, the wine caps will have plenty more roots for interaction this spring summer as I plan to have lots of peas, followed by beans in the hopes that these legumes will add plenty of N to the chips as well as offer some dappled shade for the mushrooms.  By summer time I will plant summer squash on old fertile holes for a three purposes--firstly, and obviously, I want some food growing there, secondly, I want to get some more good root growth and microbial action going in the wood chips (which should be well on their way to turning back into soil by the end of the summer) and finally to offer a little shade for more wine cap production.

This has been a very interesting long term project for me.  I first piled up my chips two years ago, let them sit for a year and inoculated them about a year ago.  My goal is to eventually convert all of my current beds into wood chip/mushroom compost beds, in effect making my own nutritionally dense and microbially active soil for my gardens.  I am especially focusing on the microbial side of things.  I can always just add more nutrients that I buy in from the store, but making the microbial communities takes fair amount of time and dedication.  I have two other beds that I plan to convert to wood chip compost starting this spring.  I need to get some sides built up and I have a nice pile of chips sitting for about a year slowly decomposing.  If things work right this spring, I will get those chips spread out and get them inoculated with wine caps and start phase two of my mushroom compost plans and I will learn from mistakes I made from my first bed.  In my first bed I used far too small a supply of initial sawdust spawn to cover the area the size of my bed.  I think that had I used about twice the initial supply of spawn I would have drastically sped up the decomposition and even had some mushrooms the first year.  I have roped in some friends who like mushrooms and this year I plan on buying in bulk so I can really get the decomposition going.  With a little luck, I will have a total of three beds of wood chip/mushroom compost.  Once those beds are completed, I plan to top off the beds each year with wood chips that I chip up from around my property.

I have rambled on again, but thanks a lot TJ Jefferson and Redhawk for all your input into my project and as always, If you see something I am doing wrong or something I can do better, please let me know.  I will keep this updated in another post I have about composting woodchips.

Thanks again,

Eric

Eric and Tj, just wanted to let you both know that I've started an in-ground mushroom bed that is wood chips mixed with donkey an hog manure (already composted for 6 months) and hyphae are growing at the rate of 6 inches per 48 hour period, this was set in motion just one week ago today, I do expect the growth rate to slow since the inoculation was from a batch of left over plugs. I spaced the plugs 4 feet apart equidistant and it appears the mycelium is trying to connect instead of growing out to the edges of the bed, they are growing only towards each other.

Thought you two would like to know about this particular trial since it relates to your own trials.

Redhawk

Redhawk,

Thanks very much for keeping us in the loop on this experiment, and thanks for thinking of us as you conduct your trials.  As I have always said, I truly appreciate all your helpful advice and sage input.  I have a bunch of chicken and hamster litter that I previously was thinking of keeping separate from the rest of the compost, but now I am thinking that this will be the perfect medium for the wine caps.

Aside from the bunny and hamster litter, I do not have access to a lot of manure.  Do you think that bagged manure would do a decent stand-in for your animal manure?  I realize that it has probably been pasteurized or treated somehow, but it does have a rated NPK level.

As always, thank you very much, but this time, I mean it especially so,

Eric

Redhawk,

I don’t suppose you have any pictures of your mushroom compost.  It would be really interesting to see what this actually looks like.  It would be highly useful for those visual learners among us.  Also, how much spawn did you use?  It sounds like you used little pegs like one might use to infuse a log.  Do I have that right or am I missing something?

Anyways, thanks for that great post.

Eric

So I have another question for those with mushroom experience,

I have a second bed of wood chips ready for wine cap mushroom inoculation and given Redhawk’s experience with composted manure accelerating fungal growth, I was thinking of trying an experiment of my own.  I don’t have access to the composted manure like some people do, so I was thinking of trying a substitute.  I was thinking that I could try adding in bagged manure, bat guano, and/or comfrey leaves in place of the composted manure.  I can probably get the nutrients right to mimic the manure, but I am thinking that only the guano (possibly) will have all the microbes.

So please, anyone with experience, let me know what you think about this potential plan.

Eric

Try everything! Throw enough experimental stuff at your chips straight from what your heart and gut tell you. Never stop experimenting please. No 2 truckloads of woodchips I've worked with over the last 7 yrs has been exactly the same in make-up. Therefore, add all the wood-eating fungal species' spawn you can find. Feed it layers of grass clippings, grass or grain straws and hays, water diluted manures, ground tree leaves, or soaked hardwood sawdust with oatmeal mixed in, etc, etc, .  

Since the wood varieties can vary considerably in each pile, or sections of any 1 pile, the more diverse the variety of Fungi and Bacteria need be it seems.

Brent,

I like your “everything but the moon” approach. Maybe I did not exactly explain my original question well, but I was wondering if the mushrooms themselves added any nutrients, especially nitrogen.  

I am now trying to add in some fertility by planting legumes and I will be adding in grass clippings and comfrey leaves to boost the nutrients.

Thanks for the input though, I will be adding in leftovers for the existing fungi to munch upon.

Eric