CaCO3 has high buffering capacity and resist change in soil pH. After CaCO3 is lost from soil, the decrease in soil pH becomes rapid. Is it because other buffers are weak? I need papers or a diagram showing the phenomenon of pH decline.
Dissolution of calcium carbonate would happen when partial pressure of carbon dioxide increases through the root system of the plants on soils. This chemical reaction will cause decrease in soil pH. Rapidity of dissolution will depend on the root volume in the soil.
As lime dissolves in the soil, calcium (Ca) moves to the surface of soil particles, replacing the acidity. The acidity reacts with the carbonate (CO3) to form carbon dioxide (CO2) and water (H2O). The result is a soil that is less acidic (has a higher pH)
Although a recent paper stated and I quote: “liming is the most effective approach amending soil acidity for agricultural soils.” it goes into the pretty complex chemistry (including references in this paper):
Dear Sir Rob Keller Thank you very much for the answer. The attachments you shared have been very valuable and thoroughly improved my understanding on the subject. Blessings.