2 year old chicken manure/straw mix ok to use now?

its been sitting in a pile in the open, not touched for the guts of 2 years, I had a look at it yesterday and it was dry and crumbly on top with bits of straw still present, no smell at all although it the heart of the pile its got a good damp "rotted grass" look to it.

I have an approx area (6mx8m) of ground that has been covered with black plastic for about to month that Im about to plant my young leaks into as well as sow a drills of Cauliflower/brocolli/celeriac into and possibily transfer my young squashes/pumpkins into later in the year and maybe even a few outdoor cucumber plants I have.

would it be okay to mix in the rotted manure/straw mix into the soil and then sow staright away or will it burn any seedlings?

I did mix a small amount of it into a few holes for rasberry plants i sat yesterday mixed with soil and watered in I also dug a trench and did a 50/50 mix with the manure/soil for some broad beans I sowed yesterday.