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CH3041
ON-LINE LECTURE 14
• BASE
CATIONS are Ca2+, Mg2+, Na+, K+
• Base
cation saturation is the fraction of
the
soil CEC that is taken up by these cations.
BCS = S cmol (Ca2+,Mg2+,Na+,K+) / CEC
soil CEC that is taken up by these cations.
BCS = S cmol (Ca2+,Mg2+,Na+,K+) / CEC
• A low
base cation saturation means a
soil is susceptible to acidification.
• A soil with significant base cation inputs
can become alkaline.
can become alkaline.
• As long as [Ca2+] > [Na+] the pH
will remain below 8.5 due to the
buffering nature of Ca2+. Ca2+ + CO2 + H2O D CaCO3(s) + 2H+
