How long have you been drying it, two week's, three weeks? After a couple weeks you should start cureing your bud is mason jars, you can use any sealable container but mason jars are glass and won't pick any bad tastes or smells. Place buds loosely in the jars close the lid tight and only open it for 20 min. aday. Do that for a month while keeping it in a cool dark place and keeping a eye out for mold. You should notice a differance after that.
As far as the hay smell, check your buds for mold. Hopefully there is none and that's not your problem, if there is sorry dude but better luck next year.