Acidity, exchangeable reserve

In axenic cultures, some EMF can get access to non-exchangeable potassium and calcium reserves in micas such as phlogopite and vermicu-lite (Paris et al., 1995a, b, 1996). Application of limiting amounts of potassium and magnesium in the nutrient media increased the release of potassium from phlogopite, and seemed to be accompanied by increased exudation of oxalic acid by the EMF (Paris et al., 1995a, 1996). Exposure... 

Salt splitting capacity is a value sometimes used to describe the strongly functional component only of a resin s total capacity. The term is usually reserved for strongly basic anion exchangers where it is identical to the value for strong base capacity or for weakly acidic cation exchange resins in which case it is a measure of the usually low capacity for the exchange of neutral cations. 

It should be stressed that the exchangeable base cation buffering mechanism does not actually neutralize the acidity but merely stores it in the soil s reserve acidity pool. If the soil is then subjected to leaching, the cost of buffering against acid inputs by this mechanism is depletion of the exchangeable base cations in the soil,... 

Reserve acidity. All titratable acidity in the soil that is associated with the solid phase. It equals in magnitude the sum of the nonexchangeable and exchangeable acidity. 

The ions in the soil solution constitutes the active acidity and are measured directly as soil pH values. On the other hand the adsorbed H+ ions held on exchange sites are not subject to pH measurements are termed as reserve acidity , both the forms contribute to soil acidity. Thus soil pH does not reflect the total acidity. However a suitable index which takes into account the reserve acidity of soil is the lime potential, which is calculated as follows ... 

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