Farmers purchased new equipment with the hopes of

That they will work better and more efficient.

Explanation:

A Duty is a responsibility that can exist because of moral or legal obligations. You're required to do those. A citizen's responsibility is something that is expected from you to do in order to help improving the society, but it is not mandatory. Voting and defending the constitution are a citizen's responsibility, but not voting and arguing against the constitution are also a citizen's rights.