PH

How the level of pH in the soil influences the plant concentration by affecting the availability of elements.

Each horizontal graph section represents an important element needed for optimal plant growth. The vertical lines represents different pH levels in the soil. The thin or narrow part of each horizontal section means that the absorption and availability of that element into the plant is reduced.

Use phosphorus as an example. You can see that when a soil has a pH of 6.5 to 7.5, the available phosphorus in the soil will be absorbed into the plants. When I studied this chart, I also learned that a soil with a pH above 7.5 is just as bad as a soil that has below 6.5 pH. The horizontal graph section for phosphorus becomes more narrow outside of the 6.5 to 7.5 range.