Iowa Code § 438.6

On or before the first day of April of each subsequent year, such company shall, in like manner, report all real estate acquired for any of the pipeline purposes above named during the preceding calendar year; and also, a list of any real estate, previously reported, disposed of during the same period, which disposition shall be noted by the department of revenue in an appropriate column opposite to the description of said tract in the original report of the same in the record of pipeline land.