Dear WW: Back when I was working on genealogy, I read about a farm near MA,RI line near seacoast/ When the owner died the evaluation of the property valued two acres of "salt meadow" equal to the whole rest of the hundred acres of the farm. I was astounded. Finally it occurred to me that the salt meadow having its nutrients replaced each year by the sea. had no decrease in yield, whereas all the inland hay acres had been so depleted by fifty years of use were virtually worthless, because the animal manure could not replace enough of the nutrients removed. No feedstore fertilizer in those days. Stupid organic farmers to the contrary.
One thing about meadow hay.It has a relatively high magnesium content and is very laxivating.