Peat smells like sulfur

[nimbulan]

I was wondering if it's abnormal for peat to smell like sulfur. I got this bag of peat a year and a half ago approximately, and have not noticed this before. I needed some CP soil yesterday and both my tub of leftover mixed soil (stored indoors, sealed) and my peat bag (stored outdoors, protected from rain) smell like sulfur.

Could the peat be breaking down? I've hardly made a dent in the bag after all this time and it feels like it would be such a waste. If that's the case, what can I do to make it last longer?

 

[DJ57]

Bad smell, bad peat, and I would not use it. It is probably breaking down. Was the leftover mixed soil wet/damp when you stored it? I have had peat go bad only when it sits in wet conditions too long, both mixed and in bales. I have had peat bales last a couple years if kept totally dry and away from moisture.

 

[nimbulan]

Yes it is moist, it came that way and there's way too much for me to dry out and try to store another way.

 

[DJ57]

Might be best to just eat the loss and throw it all away. Are you able to obtain another bale of dry peat moss? How much do you need at the moment?

 

[nimbulan]

I'm not sure where I could get dry peat moss. Stores always sell the usual wet bales. You mentioned a bag company of some sort on Saturday, but I'm not sure if I'm looking at the right business.

I was just using the peat to sow the seeds I got from you, though I already mixed the soil and did it so it's probably too late to change now. I can certainly look for another source of peat for the spring since I have plenty of plants that will need bigger pots for next year.

 

[DJ57]

Sending PM in a second.

 

[Whimgrinder]

DJ is right. Soggy peat stored in the bale for long will encourage anaerobic bacteria, and its the bacterial action that generates the Hydrogen sulfide you're smelling.
Its not unusable, but you have to either 1) dry it out or 2) "cook" it to sterilize it.

 

[Est]

As mentioned, the rotten egg smell is generally hydrogen sulfide, H2S, brought on by anaerobiosis. You pull something that is entirely organic matter, destroying any structure it had, and let it sit in a wet bag for a while and you're gonna end up with anaerobic critters growing. The sulfur was always there so it's not that the soil is bad. H2S is quite volatile, so if you remove the source you remove the problem

In short, let it dry out and air out and you'll be fine. There's no point in trying to sterilize the material - the bacteria were there the whole time, not harming anything. Any obligate anaerobes are going to perish or go dormant as soon as you dry it and air it out. I'm not a fan of sterilizing media in any case, though.

 

[nimbulan]

I understand your position there. I've read that sterilization tends to cause the media to degrade faster.

Finding space to dry all that peat out could be an issue though. It's winter in Oregon which means it'll stop raining about...June. And I certainly don't want that sulfur smell indoors.

 

[Est]

I would worry about airing it out on an as-needed basis. If you can keep the bulk from sitting wet, that's great, but I don't think that sitting anaerobic in the meantime is an issue. Much of your peat had probably been sitting anaerobic for many, many years before if ever got to you. And yeah, beyond any media breakdown as a result of sterilizing with heat, I just don't generally see the point. It seems like a lot of work to avoid moss, and I don't think that avoiding the native community of microbes is necessarily desirable. Soil microbes tend bounce back from significant abuse incredibly quickly -I've measured methane production (another anaerobic byproduct) within minutes after wetting up soil that'd been parched for months!- and in the meantime they're not doing anyone any harm.

In this instance I'd want the microbes around anyway because they're a useful indicator: if the media in your pots starts to stink, you know that you're overwatering and/or your media isn't "breathing" sufficiently.

Hope that helps!