(a)
(1) Every public grain warehouseman shall receive for storage or shipment, so far as the available capacity for storage of the public grain warehouse shall permit, all grain tendered to him or her in the usual course of business.
(2) However, a public grain warehouse owned and operated as a cooperative may decline to accept grain tendered by a nonmember if the cooperative reasonably believes that its available capacity will be required to serve the members of the cooperative.
(b)
(1) The depositor and the public grain warehouseman may agree upon a sample taken from the lot of grain to be offered for storage as being a true and representative sample.
(2) The depositor and the public grain warehouseman may agree upon the grade of the grain offered for storage, and a warehouse receipt may be issued on the agreed grade.