Composting Moldy Hay

Hello, I am a new person to the forum and new to composting. I have a several 4x6 round bales of moldy hay that had gotten rained on before I could bale it. Since the hay is unfit to feed to anything I want to compost at least some of it.

Four days ago I was able to peal off about half a bale. I would make a layer about 8 inches thick then put some water and some activated sludge from where I work onto the layer and repeat the process. I abandoned the left over 3 foot in diameter core of the bale by laying it on its flat end, scattering 5 gallons of activated sludge and putting about 100 gallons of water on it.

In two days the layered pile was starting to steam and get rather warm - almost hot. Mean while the upended core only gotten mildly warm in the very center; the softer part of the core. This morning I used a tractor to unroll the core that I had abandoned. I also turned the pile over. I was able to see what the hot spots in the pile were caused by and it caused me to question my progress.

The hot spots looked like big patches of whitish mold although I have no idea what it is. I am not sure if this is what I want to see or not and that is where I need some advice from the forum. I have a clump from a hot spot pictured along with some of the yet unaffected stuff in the pile. Thanks in advance.

I believe that white stuff is actinobacteria. They're pretty normal in compost piles, especially when the temperature gets hot, and their presence is responsible for the pleasant, earthy smell that good compost should have

That is good to know because there is a lot of it in there.

But I am convinced that I am going to have to add more stuff to the pile like manure and wood chip to get the fast reaction I was hoping for. The stuff is available but I will need to borrow a dump trailer and haul it in. In the picture that pile is one bale. I have 57 more to go. Any Ideas?

Not to freak you out or anything, but large piles can get really, really hot when bacteria have the right balance of food. It's not unheard of to have them catch on fire. If you're going to be throwing more nitrogen into a mostly carbon pile, I'd think about getting a compost thermometer so you can monitor the temperatures in the middle.

hau kittum, I think you would be better served to just pile that back up and maybe water it a little, then let it go do what it will do. I use straw bales for some gardening and I can assure you that the actinobacteria will do a fine job of heating up that hay, with out needing to make any additions.
As Alex mentioned, it is possible to have hay get to spontaneous combustion temperatures when nitrogen is added to already heating heaps.

With as many bales as you have, you have some choices on how to build your heaps. You could do a strip heap or even three. In these you just make up a heap three bales high and as long as you desire. You could do three bale heaps and not extend them so you have a little more controllability of each heaps moisture content and temperature. Add in manure as layers is another option and would heat that manure to good temperatures for sterilizing the pathogens out of the manure. This method would mean making the heaps in layers with thin layers of manure between thick layers of the hay. Nothing else needed.

Alex Veidel wrote:Not to freak you out or anything, but large piles can get really, really hot when bacteria have the right balance of food. It's not unheard of to have them catch on fire. If you're going to be throwing more nitrogen into a mostly carbon pile, I'd think about getting a compost thermometer so you can monitor the temperatures in the middle.

It is getting a bit warm, even hot in places. I was happy to see it vaporing off real early this morning. I think I'll leave it alone this week end and see what it does. And yes I think a long probe thermometer is needed.

Bryant RedHawk wrote:With as many bales as you have, you have some choices on how to build your heaps. You could do a strip heap or even three. In these you just make up a heap three bales high and as long as you desire. You could do three bale heaps and not extend them so you have a little more controllability of each heaps moisture content and temperature. Add in manure as layers is another option and would heat that manure to good temperatures for sterilizing the pathogens out of the manure. This method would mean making the heaps in layers with thin layers of manure between thick layers of the hay. Nothing else needed.

I think you and Alex are right. I need a way to deal with potential tempture issues and and big lumpy pile is not the best way to do this. I think you guys may like what I came up with.


I know there is a dealer around here for these things or something similar. I will check on renting one of these. Talk about mulching a garden! I was tinking about setting this gizmo up to shred the bales into long rows. I would keep going adding to the row untill I had the right height then move over and make another row. Then I would rince out the old herbiside sprayer, make a few easy modifications, then use it to soak the rows down with some inoculant. I most likely would not be able to turn the rows, but some time next summer, load the product up into my mom's giant manure spreader and scatter it all over the hay field. Between the compost, Sea-90, and subsoiling we should be able to take an under performing part of the hay field and make some good hay for a bunch of milk cows.