Card from 2009 showing Hay Bails...
Missouri is well known for its agriculture and has the second largest number of farms of any state. Some of the major crops are soybeans, corn and hay. Missouri also produces a large number of cattle and hogs.
(from the back of the card)
I think that the second and the third stamp are more than familiar, but the first one hasnt been really presented...it is a self-adhesive sunflower stamp issued in 2008.