To guarantee the Jiangsu coastal salt industry, the system of
AGSD had been implemented for a long period. However, the rapid
accretion in the Jiangsu coastal zone generated a large area of grass
land that was suitable for reclamation, i.e., a large amount of arable
land were not utilized for agriculture (Sun, 1984). Generally, under
the salt industry oriented policy, the coastal agricultural development
experienced long-term difficulties in the 16e19th centuries.
The situation was not changed until the late 19th century.