does saprotrophic mycelium benefit from nitrogen?

I vaguely remember seeing a documentary on button mushroom cultivation where they were adding chicken manure to the substrate for added nitrogen. That being said, most of what i've read regarding substrate focuses on adding carbohydrates through flours, grains, sugar, etc.

I'm playing around, in my head, with the idea of combining straw bale gardening with saprotrophic mushroom cultivation. Inoculating in fall, i can get fresh bales and put them out in October after the slugs have gone into hibernation so as not to provide extra habitat. Then I have 5 months of cold incubation for the mycelium to colonize and start to break down the bales before growing season starts in February, which with the heat coming off the bales, and a hoop on top i can get started early. I might have to fertilize (urine) the bales in February, though so that plants can grow healthy. Will the fertilizer be bad for the mycelium?

When I use urine as a fertilizer on any project involving straw, I usually see various kinds of inedible inky cap mushrooms pop up, especially from the old Coprinus radiatus group- the Miniature Woolly Ink Cap. These kinds of mushrooms are considered "weeds" by commercial Agaricus and Pleurotus (Oyster) growers. They also indicate that an excess amount of nitrogen is remaining after the composting process has been completed. In fact, I just noticed some of these "weed mushrooms" in my Almond Agaricus/ leached cow manure project- not a good sign! The more nitrogen added to a mushroom substrate, the more contamination problems pop up.

If you do try inoculating straw bales with oyster spawn, try to get a cold weather strain. Field and Forest has a lot of strains to choose from. It's a cool idea (no pun intended). I wish you luck with your project and that you can report back to us with the results!

M.K. Dorje Jr. wrote:When I use urine as a fertilizer on any project involving straw, I usually see various kinds of inedible inky cap mushrooms pop up, especially from the old Coprinus radiatus group- the Miniature Woolly Ink Cap. These kinds of mushrooms are considered "weeds" by commercial Agaricus and Pleurotus (Oyster) growers. They also indicate that an excess amount of nitrogen is remaining after the composting process has been completed. In fact, I just noticed some of these "weed mushrooms" in my Almond Agaricus/ leached cow manure project- not a good sign! The more nitrogen added to a mushroom substrate, the more contamination problems pop up.

If you do try inoculating straw bales with oyster spawn, try to get a cold weather strain. Field and Forest has a lot of strains to choose from. It's a cool idea (no pun intended). I wish you luck with your project and that you can report back to us with the results!

Thanks for the heads up. Its really appreciated! I guess I will be growing: carrots, peas and beans in my mushroom substrate then!

Some mushrooms thrive with added nitrogen, but add nitrogen once it has established itself. For example, if you have shaggy parasols in a regular patch, you probably want to add nitrogen, in the form of urine or green leafy matter, such as recently cut but not old grass. They would be considered saprophytic. I think you have to be really specific about the type of mushroom and the substrate.
John S
PDX OR

dan long wrote:I vaguely remember seeing a documentary on button mushroom cultivation where they were adding chicken manure to the substrate for added nitrogen. That being said, most of what i've read regarding substrate focuses on adding carbohydrates through flours, grains, sugar, etc.

I'm playing around, in my head, with the idea of combining straw bale gardening with saprotrophic mushroom cultivation. Inoculating in fall, i can get fresh bales and put them out in October after the slugs have gone into hibernation so as not to provide extra habitat. Then I have 5 months of cold incubation for the mycelium to colonize and start to break down the bales before growing season starts in February, which with the heat coming off the bales, and a hoop on top i can get started early. I might have to fertilize (urine) the bales in February, though so that plants can grow healthy. Will the fertilizer be bad for the mycelium?

That chicken manure was added to make proper button mushroom compost. Phase 1, it gets hot, gets turned a few times. Phase 2 they try to steam all of the excess nitrogen off, leaving about 1% or so N content before inoculation. So no, you don't want too much N or you will likely get more contamination.