Chemistry & Root Zone
pH is a measure of acidity or alkalinity in the root zone, defined as the negative logarithm (base 10) of hydrogen ion activity:
pH = −log₁₀(aH⁺)
Because pH is a negative logarithmic scale, each whole-number change represents a ten-fold change in hydrogen ion concentration. Small numerical shifts can therefore produce large chemical and biological effects.
Explore related topics that build on the ideas in this article.