Oregon Revised Statutes Food and Other Commodities: Purity, Sanitation, Grades, Standards, Labels, Weights and Measures § 633.388

(1) A report of official sample, signed and acknowledged by a chemist employed by the State Department of Agriculture, other state agency or laboratory facility designated by the department, relating to the analysis of any fertilizer, agricultural amendment, agricultural mineral or lime product is prima facie evidence that the sample identified in the report of official sample was properly analyzed and that the substance analyzed contained the constituent parts stated in the report of official sample.

(2) A report of official sample, signed and acknowledged by the department, relating to the sampling of any product is prima facie evidence that the sample identified was taken from parcels, containers or lots identified in the official request for analysis.