The economic upturn was chiefly propelled by improved agricultural technologies; ... and foreign trade; and the development of a money economy. ... By the later Song dynasty the Chinese began to use the abacus, ... cultivated a taste for such products as silk and tea, and there was a ... You Might Also Like.The economic upturn was chiefly propelled by improved agricultural technologies; ... and foreign trade; and the development of a money economy. ... By the later Song dynasty the Chinese began to use the abacus, ... cultivated a taste for such products as silk and tea, and there was a ... You Might Also Like.