Soil analysis requires a lot of individual hand extraction and quality checks along the way to insure results are reported with respect to meeting required quality criteria.
Each day, our lab supervisors evaluate their processes and identify ways to improve the quality and consistency of results. It really comes down to training people with respect to proper procedures and methods and helping them identify potential issues that can occur.
The result is a soil testing report for growers to assist them with their soil fertility needs. (See earlier post on Soil Testing Results)