Answer:
The development that allowed Chinese agriculture to flourish under the Song dynasty was the introduction of new rice crops from Vietnam. These new rice varieties, which had a shorter growing season, enabled multiple harvests each year and significantly increased rice production, contributing to the prosperity of Chinese agriculture during the Song dynasty.
Step-by-step explanation:
Under the Song dynasty, Chinese agriculture experienced a significant boost due to the introduction of new rice crops from Vietnam. These rice varieties had a shorter growing season and were more productive than the traditional strains. As a result, they allowed for multiple harvests each year, significantly increasing rice production. The combination of these new rice varieties, the spread of irrigation techniques, and the creation of large reservoirs played a vital role in the flourishing of Chinese agriculture during the Song dynasty, contributing to the economic and cultural prosperity of the era.