The lime requirement of ponds can be determined by direct titration with standard sulfuric acid of the
amount of alkalinity neutralized by the exchangeable acidity displaced from a bottom soil sample
equilibrated with a solution of 1.0 N in potassium ion and 0.04 N in bicarbonate (2 mg CaCO3 equivalent
mL−1). This procedure, called the K-bicarbonate method here, provided precise estimates of lime requirement
that were 9.6% to 27.2% (average = 12.9%) greater than those obtained by the method currently recommended
for use on pond soils. It is likely that the K-bicarbonate method neutralizes more of the
exchangeable acidity in pond bottom soil samples than does the current method recommended for pond
bottom soils and thereby provides a more reliable estimate of lime requirement. Moreover, the Kbicarbonate
method does not require a hazardous chemical, a mechanical shaker, or a pH meter as does
the current method for pond lime requirement. The cost per analysis also is cheaper by the K-bicarbonate
method than with the method currently recommended for pond soils.