Cation Exchange Capacity (CEC) of Soil (Leaving Cert Agricultural Science): Flashcards

What does CEC measure?

Soil's ability to hold positively charged nutrients (cations)

Unit for measuring CEC

$\text{cmol}^{+}/\text{kg}$

Role of $\text{Ca}^{2+}$ in plants

Cell wall strength

Role of $\text{Mg}^{2+}$ in plants

Chlorophyll production

Role of $\text{K}^{+}$ in plants

Water regulation

What increases soil CEC?

Higher clay content and higher organic matter

Most common CEC measurement method

EDTA titration method

CEC range for sandy soils

1-5 $\text{cmol}^{+}/\text{kg}$ (low nutrient holding capacity)

CEC range for clay/organic-rich soils

20 $\text{cmol}^{+}/\text{kg}$ (excellent nutrient retention)

Benefits of higher CEC

Better nutrient retention, less leaching, stable fertility