Maintaining Quality Data

So, who regulates agricultural lab quality? What federal government agency assures that an individual lab subscribes and adhere to a specific quality standard? Many of you reading might be surprised that there is no defined government regulatory agency for the agricultural laboratory industry, but this done not mean there are no rules or standards.

Some states require that if you perform agricultural analysis, that you be certified within that state. Wisconsin takes a step further and specifies the lab methods that must be followed as part of the state’s nutrient management regulation. These state certifications can be simply a permit process, other states verify that the soil test results fall within an acceptable range. For example, the state of Iowa specifies that “laboratories must achieve an average score of 80% or greater in the Iowa program of the NAPT soil Testing Proficiency Program” on 6 key lab analysis.

Within the agricultural laboratory industry, proficiency programs are the fundamental way to validate lab data. While these programs are voluntary, they are required for a lab to be certified in some states. The larger reason for a lab to participate and pass is to prove the lab produces quality data. Quality data is the terms of repeatable constancy over time.

Labs that participate in a soil testing proficiency program will receive a set of soil samples. These samples have been selected from around the country for specific parameters by the proficiency organization staff. A wide variety of soils are selected to thoroughly test the labs ability to produce soil test results that match the proficiency testing organizations results. Different standardized methods are used in different regions for the county, so the proficiency organization determines acceptable value range for all of the standardized lab methods. The proficiency program identifies an acceptable range of soil test results and then scores each laboratory as to how close the lab results match up with the proficiency organizations results. Often these test samples are sent to the participating labs quarterly. Labs must meet these quality levels for an extended period of time to earn and retain certification by a state or proficiency program.

A similar concept is used within the lab on a daily basis. The lab has two check soils that are prepared in relatively large quantities and in such a way to ensure that they are very uniform. These check soils are placed within the sample flow, one being known to the lab staff, and another as a "blind" check. The quality control department tracks the data generated from the these check soils to verify that data output is consistent over time. Approximately 10% of the soil samples analyzed at ALGL are check soil samples. 

In short, those labs that display current state and proficiency program certification are showing that they can reliably produce data that matches set quality guidelines.

For more information on the proficiency programs ALGL participates in go to: Certifications and Credentials | A&L Great Lakes and click on the links to learn more about the individual proficiency programs.