worms in manure

[charles]

 It will be fine. Manure in old heaps (and compost heaps) attracts red brandling worms which eat the part rotted manure and excrete worm compost. Yours was not quite at that stage so you did not see any brandlings, but it will be attractive to earthworms in the soil (lumbricus terrestris, different worm) who will be delighted to eat it when temperatures are high enough, and gradually it will be mixed into the improving soil below your plastic, with the worms creating a great structure of drainage and root channels.