well rotted sawdust ???

Just picked up a couple of pu truck loads of sawdust from the sawmill today. First load was fresh stuff for use in humanure pile. Second load was dark brown to black, earthy smelling and had plenty of mycelium in it. Is that well rotted enough to add to soil without supplementing nitrogen?
Thanks

My son has had good luck planting in sawdust as you describe...he dug it at an old, old saw mill site. Yours sure sounds well rotted the way you describe it. I used some that was very old but not well rotted one time and it was not good for the plants...the blueberries all died.