Question

13. A soil contains 30% smectite, 10% kaolinite, and 2% organic matter. Calculate an estimated CEC for this hypothetical soil.

Answer 1

Answer:

estimated CEC for given hypothetical soil is  26.25 meq/100g.

Explanation:

Average CEC in smectite =  62.5 meq/100g. Since it ranges from(25-100 meq/100g)

Average CEC in kaolinite = 10 meq/100g.

Average CEC in organic matter = 325meq/100g.

Range(250-400 meq/100g).

Estimated CEC for given soil will be,

$=30\% \times\ avg.\ CEC\ in\ smectite + 10\% \times \ avg.\ CEC\ in  \ kaolinite +2\% \times avg\ CEC\ in\ organic\ matter.$

$= 0.3\times 62.5 + 00.1 \times 10 + 0.02\times 325$

= 26.25 meq/100g.