St. Mary's City in St. Mary's County, Maryland — The American Northeast (Mid-Atlantic)
Agricultural Change and Environmental Damage
Pollen analysis gives us important clues about the changing landscape at different points in time. The 1758 granary and 1785 barn essentially capped the soil beneath the buildings and stopped the accumulation of additional, air-born pollen. Study by Dr. Gerald Kelso revealed that these soils contain different pollen frequencies. In particular, there was far more ragweed in the earth under the later building. Ragweed is closely associated with plow agriculture, and its pollen is broadly dispersed by the wind. The difference in pollen under the two buildings is probably because in the decades before Hicks built his granary in 1758, the main crop was tobacco grown with hoes. When Mackall built his granary 27 years later, wheat was widely grown and ragweed was abundant in the open fields.
The eighteenth century witnessed the changeover from hoe cultivation to plow cultivation, illustrated above in a detail from Earl Hofmann's sweeping panorama, The Land and Man. The widespread adoption of wheat agriculture is confirmed by analysis of pollen from soil beneath the Hicks' and Mackall granaries.
Ragweed pollen recovered from St. Mary's City. Actual size of a ragweed pollen grain is about 1/25,,000 of an inch in diameter.
Studies of the sediment and pollen in core samples taken from nearby St. John's Pond confirm the heavy erosion and siltation caused by the move to open field cultivation with plows. The size of the pond declined dramatically as the area filled in with topsoil washed from the surrounding fields.
Erected by Historic St. Mary's City.
Location. 38° 11.001′ N, 76° 25.787′ W. Marker is in St. Mary's City, Maryland, in St. Mary's County. Marker can be reached from Point Lookout Road (Maryland Route 5) 0.4 miles west of Rosecroft Road, on the left when traveling west. The marker is inside the open-air barn. Touch for map. Marker is at or near this postal address: 16721 Point Lookout Road, Saint Marys City MD 20686, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within walking distance of this marker. Dating Changes in a Building (here, next to this marker); Who Worked Here? (here, next to this marker); What Kind of Barn Was This? (here, next to this marker); A Pressing Situation (here, next to this marker); To Market! To Market! (a few steps from this marker); Constructed With Colonial Ideas (a few steps from this marker); Carpenters' Marks (a few steps from this marker); Tree Growth Rings (a few steps from this marker). Touch for a list and map of all markers in St. Mary's City.
Categories. • Agriculture • Colonial Era •
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Credits. This page was last revised on September 2, 2019. This page originally submitted on September 2, 2019, by Devry Becker Jones of Washington, District of Columbia. This page has been viewed 41 times since then and 6 times this year. Photo 1. submitted on September 2, 2019, by Devry Becker Jones of Washington, District of Columbia.