Phosphatic limestone and horse country

University of Kentucky soil tests still show that edge over the rest of the state—about two-thirds of Bluegrass samples testing high for phosphorus in a late twentieth-century lab series.

After the Revolution, from about 1780 to 1820, Virginia and Carolina horse-raising families pushed west onto that forage-rich ground just as industrial America needed more horsepower. UK equine soil scientist Joshua McGrath argues the Horse Capital story starts with geology and settlement timing—high soil phosphorus supporting forage yields before commercial fertilizer—not a magic bone myth alone.