Good question from Paul:
I have several damaged wheat straw bales that I would like
to try vermicomposting with. they are 3′ x 3′ x 8′ weighing about 500
lbs each. I am wondering if I run them through a tub grinder and make
a long row on the ground if the worms would thrive in this row or
would I need to add something else for them to survive? What might
happen with this arrangement in the winter time? Here in South Dakota
it gets very cold in the winter but I think if the row of straw were
big enough there would be enough heat generated from the wet straw?
To a rabid vermicomposter like myself, that sounds like the ultimate cool opportunity to grow some worms. I’m definitely jealous – worms LOVE rotten straw! The fact that you have access to a tub grinder is definitely an added bonus. By increasing the surface area of this material you will definitely improve its food value
I’m not sure I’d class it as an ‘ideal’ worm food on its own however, since straw has a fairly high C-to-N ratio. I’m sure you could grow a population of red worms in it if it stayed wet and warm, but they might be on the small side, and the population might not grow as quickly as it would if you had some aged manure mixed in with it (run that through the tub grinder too – assuming it is solid like horse manure – smaller particle size can have a HUGE impact on worm growth). Food waste would work well too, but I get the feeling you might be able to track down some manure fairly easily.
The size of the windrow and the protective layers you add will have a major impact on its potential for winter activity. You may want to dig a trench and also add a really thick layer of dry straw over top. If above ground simple pile it up nice and high to help stimulate natural heating – adding manure and/or other good N-sources will be important in this case. If you contain everything within walls of good straw bales this could also really help keep the warmth in (large size will still be important though). This is what I did with a large outdoor bed last winter and it performed very well.
Do be careful with piling it up too much during warmer months though – the last thing you’ll want to do is have it overheat on you and kill off your worms. Maybe just start with the rotting straw in shallow trenches and gradually start to add manure, a little at a time until the cool weather really starts to arrive.
Anyway – hope this helps!