The creation of aqueducts made it less important to trade food.
Step-by-step explanation:
The Romans had needed to import grins and other food material as the population of the city had grown big in a few centuries and the surrounding area was either urbanized or was not enough to support the whole population.
To help this, the Aqueducts were built as an extensive irrigation system that lasted for ages without needing repair and provided water for farms for long time to come.
This made the area produce more food and was able to feed the large population of Rome because of it.