The labs listed in the second category are the ones generally involved with the high brix movement/methods.
The labs in this list are organized in two broad categories:
1. those that emphasize a biological assessment, and
2. those that emphasize mineral content and fertilizer recommendations
The first category focuses on tests for biological parameters and associated indicators such as soil organic matter and microbial activity. Farmers using organic production methods employ a range of biological farming practices to achieve a healthy, productive soil—e.g., crop rotations, cover crops and green manures, composts, minimally processed rock minerals, and in some instances, microbial inoculants. Accordingly, they need data that indicate soil biological health, not just mineral composition. They also need to understand how they can adjust agronomic practices to improve organic matter, soil tilth, microbial diversity, and nutrient mineralization and how this will affect their farm production.
The second category emphasizes mineral availability and mineral balances in the soil. The labs listed in this category provide organic fertilizer recommendations, conduct modified lab tests considered special or unique, or provide recommendations based on alternative fertility concepts developed by agricultural advisors like William Albrecht, Carey Reams, Rudy Ozolins, and Arden Andersen.