Final answer:
The increase in food production and food surpluses in China during the Song dynasty were primarily due to the use of new strains of rice that allowed for two harvests in a year, the adoption of new agricultural technologies like irrigation, and the governmental support in stabilizing agricultural markets and spreading more efficient crop seeds.
Step-by-step explanation:
In China, an increase in food production and the resulting food surpluses were led by various factors during different periods of history. During the Song dynasty in the eleventh century, one of the major factors was the use of new strains of rice that ripened quickly enough to allow for two harvests in a single year. This increased the overall food production in China and led to food surpluses.
Another factor that contributed to the increase in food production and surpluses in China was the adoption of new agricultural technologies. For example, the invention of irrigation techniques, such as chain-driven pumps, allowed unused hillsides to be transformed into cultivatable land. This expansion of cultivatable land further increased food production in China.
Additionally, the stability of agricultural markets and food prices by the Song government, as well as the spread of more efficient crop seeds, played significant roles in increasing food production and leading to food surpluses in China.