Iowa Code § 637.425: Property not productive of income.

1. If a marital deduction is allowed for all or part of a trust whose assets consist substantially of property that does not provide the surviving spouse with sufficient income from or use of the trust assets, the spouse may require the trustee to make property productive of income or convert property within a reasonable time. The trustee may decide which action or combination of actions to take.

2. In all other cases, proceeds from the sale or other disposition of an asset are principal without regard to the amount of income the asset produces during any accounting period.