Iowa Code § 39.21: Nonpartisan offices.

There shall be elected at each general election, on a nonpartisan basis, the following officers:

1. County public hospital trustees as required by section 347.25.

2. Soil and water conservation district commissioners as required by section 161A.5.

3. County agricultural extension council members as provided in section 176A.6.

4. Township officers as provided in section 39.22, subsection 2.