Perfectly safe to use but use it as sparingly~ as you would a fertilizer.
It's strong stuff. The ammonia smell is indicative of its nitrogenous
content.
Best Wishes Brian.
"Rhiannon Macfie Miller" wrote in message
...
I have about half a sack of chicken manure left over from
last year. It now smells of ammonia instead of henhouse.
Is it still useable, and is it still useful?

Rhiannon