Pleurotus bucket is growing; compost is confusing

Well, my slapdash attempt at growing oyster mushrooms is coming right along. There’s definitely some mold contamination in some spots, but it’s very limited. [ETA 9/28: Yeah, not so much with the limited anymore.] The mycelium is doing its thing.

You can get a kit from Fungi Perfecti for growing a bucket full of Pleurotus on coffee grounds. (Not to mention a lot of other neat kits. I’m taken with the shaggy manes and garden giants.) I think they may mix in some more carbonaceous materials, and I’m pretty sure they start with a whole lot of sawdust spawn. That might give Pleurotus a boost in outcompeting the mold.

Speaking of Fungi Perfecti, I talked to a guy there who hasn’t seen any ill effects from using spent Pleurotus bags in his compost. (Nice, helpful guy. Myco geeks rule.) The inhibition effect was seen by a woman who grew it together with vegetables; I wonder if perhaps the stuff is just so aggressive that it’ll sometimes go after root hairs. It’s pretty hungry stuff.

I’ve been reading up about this critter. People who grow it at home without a lot of experience or equipment have reported no little trouble getting it to fruit. That sometimes might be because they don’t know, as I didn’t know, that it requires light to form primordia (“pinheads”) and fruiting bodies. Chang and Miles say, in their wildly expensive textbook Mushrooms, “The [formation of primordia] requires light of 200 lux intensity for over 12 hours. The growth of the fruiting body requires light of 50 to 500 lux intensity.”

I’ve also been reading up about compost, and getting a lot of contradictory advice with not much in the way of scientific references, and all of it strongly expressed. Add lime! Don’t add lime! Hot! Cold! Add soil! Don’t add soil! Yay wood chips! Boo wood chips! For crying out loud. The TAMU guide has some hiccups but might be the best of the lot. Its take on lime is interesting:

Ammonia escapes as ammonia hydroxide as the pH rises above 7.0. In the later stages of composting the pH may rise to between 8.0 and 9.0. At this time there should not be an excessive amount of nitrogen present as ammonia. Materials which contain large amounts of ash will have a high pH and may be expected to lose more nitrogen.

Some compost operators have suggested the addition of lime to improve composting. This should be done only under rare circumstances, such as when raw material to be composted has a high acidity due to acid wastes or contains materials which give rise to highly acid conditions during composting. It is recommended that when the pH remains above 4.0 to 4.5, lime should not be added. The pH will be increased by biological action and nitrogen will be conserved.

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