Each state department, including each of the agencies therein, shall identify each nonexpendable property item in its possession worth at least the amount prescribed by the state auditor by make, model, serial number and acquisition cost and by affixing a numbered tag or a similar marking to it. The head of each department shall be responsible for the proper use and retention of this property. Each department shall keep currently an inventory of all this property in the form which shall be prescribed for such an inventory by the state auditor.