Soil pH relationships and mineral solubility
The Truog diagram, developed in the 1930s and 1940s, is a conceptual tool that illustrates how soil pH influences the availability of essential nutrients for plants. This diagram, which includes 11 nutrients, shows that for most plants, a pH of about 6.5 is ideal for nutrient uptake.
However, this diagram should not be used to predict the actual amount of available nutrients, as this also depends on the crop type, soil, and fertilization.
Original diagram
Here is the original 1946 diagram:
Current diagram
An incomplete diagram
Recent research[1] in soil fertility and plant nutrition has shown that Soil pH affects not only nutrient solubility but also their concentration in soil solution, ionic form, and mobility. It is recognized that the interactions between nutrients and the different plant responses to pH variations are complex and cannot be generalized simply by a diagram.
Nutrient availability depends on many factors, and numerous exceptions make the Truog diagram unreliable for precise agricultural applications. Farmers are advised to not rely solely on this diagram for agronomic decisions, but to consider a more comprehensive and personalized soil analysis and the specific needs of their crops. Soil pH is a useful indicator but alone cannot accurately estimate nutrient availability for plants.
Source
Taken from "Alfred E. Hartemink · N. J. Barrow, 2023" by Martin Rollet, agronomist.
- ↑ Barrow, N.J., Hartemink, A.E. The effects of pH on nutrient availability depend on both soils and plants. Plant Soil 487, 21–37 (2023). https://doi.org/10.1007/s11104-023-05960-5
