The Manure Analysis Proficiency (MAP) Program.

The Minnesota Department of Agriculture (MDA) manages the only manure proficiency testing program in North America. Beginning in 1996 with 14 laboratories, the program expanded to over 70 laboratories after receiving a grant from the US Environmental Protection Agency in 2003.

Through the program, manure testing laboratories have the opportunity to demonstrate their analysis accuracy and precision. The MDA prepares homogeneous manure samples and provides two sample exchanges each year to participating laboratories. Each exchange consists of three different manure samples with triple replicates (nine containers). The replicate samples allow the MDA to evaluate laboratory precision within an individual laboratory in addition to the traditional accuracy evaluation between laboratories.

In 2015, the MDA invested in a new laboratory with a freeze dryer, rotary sample splitter, and equipment to encapsulate manure to develop manure reference standards in addition to the standard manure proficiency samples. The reference standards will give laboratories another tool to help maintain calibration on their analytical equipment and methods.

Results submitted by laboratories in proficiency programs often have extreme outliers, and the MAP Program is no exception. Some outliers result from reporting errors related to data entry on the program’s reporting spreadsheet. However, more serious errors are due to improper methods or faulty equipment. To help determine if an error is primarily a clerical error, or a more serious error, the MAP Program allows participants to submit client reports for each sample in addition to the standard reporting spreadsheet. If a laboratory is flagged for poor accuracy or precision, the client reports help the MDA determine if the error was related to filling out the standard report form, or a more serious error related to methods or equipment.