Large crops of salt marsh hay formerly were gathered on hundreds of acres of marshland. To keep the hayrack horses from sinking into the marsh, 7" by 10" oak slabs were fastened to their hooves.The horses would only come out after the ground had begun to freeze, oak slabs or not! To prevent the tides from washing away the pre-harvested salt hay, the cut hay was piled onto "staddle sticks," the remnants of which can still be seen in the marsh today -- small groupings of stakes that peek out of the marsh at intervals. You've probably seen them when driving by on Route 1 but never know what they were (like me)!
Apparently, the salt hay was very desirable to farmers as feed, and as an additive to the piles of regular hay kept in their barns. The salt content in the hay made it fire resistant, and adding it to the regular hay in their lofts lowered the risk of a quickly-spreading barn fire, one of the more devastating hazards for farm owners and their animals. (Source)