I had the same problem w/ the hay smell for a few grows. I finally have it beat.
I think one of the problems is that there are no real set times as far as drying and curing goes. Ive found through my experience bud density, temp, humidity all play a part in the process.
Heres what I now do to dry and cure.
1. At harvest I leave the buds on the main stocks, it helps protect against too quick of a dry. I do a good trim on all buds but leave a little bit of the smaller leaves.
Discard all fan leaves, save smaller trimmed leves and small buds for hash making.
2. I hang the stocks from clothes hangars in my grow room above the light. Air is moving, but there is no direct fan on the drying buds. The trimmed small buds and leaves are placed in a paper bag to dry.
3. After 3-4 days I start paying alot of attention to the hanging buds. I'm looking for the outside of the bud to be crispy, but the inside to still have some moisture. I make sure I pull them before the entire bud gets crisp, thats where for me the key is. If you wait too long and the buds get crisp throughout, the bud dosent cure to its full potential.
4. Once the buds are at the stage I want them, I place them into plastic Ziploc containers. I leave the buds covered for 12 hours and then open it and check. If the outer part of the bud is damp at all I leave the container open for 12 hours. They then stay closed and sealed for 6-7 days with an opening and rotating of the buds every day.
After the 7 days I take a sample and go from there.