Iowa Code § 6B.30: Additional deposit.

If, on the trial of the appeal, the damages awarded by the commissioners are increased, the condemner shall, if the condemner is already in possession of the property, make such additional deposit with the sheriff, as will, with the deposit already made, equal the entire damages allowed. If the condemner be not already in possession, the condemner shall deposit with the sheriff the entire damages awarded, before entering on, using, or controlling the premises.