Most soil tests are quantitative — they deal almost exclusively with numbers. But life processes are hard to pin down when they are actually alive. What can work better to give an overall picture of the health of the soil is just that: a picture. Chromatography for soil analysis was developed by Ehrenfried Pfeiffer to provide a way for farmers and growers to perceive the activity in the soil in a visual way — a complement to soil test print-outs, but in no way a replacement.