Choosing a Commercial Ag Laboratory

Soil chemical analysis is the cornerstone of an effective nutrient management program. Without a reliable soil test, significant miscalculations in fertilizer recommendations can occur, leading to drastic effects on profitability and the environment as a result of under and overfertilization and soil amendment recommendations.

Despite the large number of analytical commercial laboratories serving California agriculture, deciding which laboratory to send a sample to can be a daunting task. Unfortunately, there are no public data reporting the accuracy of the analysis performed by agricultural laboratories, and there isn’t a “true” certification program in the U.S. Although a lab may participate in a proficiency program such as the Agricultural Laboratory Proficiency (ALP) program or the North American Proficiency Testing (NAPT), these programs are not mandatory, nor do they certify lab quality. Therefore, laboratories are chosen based on “word of mouth” and prices, which can vary significantly.

Because of the absence of data, growers, farm managers, consultants, environmentalists and even researchers are left without a reliable means by which to select a testing laboratory. A study was conducted in 2018/2019 to assess the performance of soil testing laboratories.

Please access the links below for a full description of the project and its results:

PowerPoint presentation file:  Biscaro_FREP_final

CDFA FREP's conference recording: