1) The rate of gypsum dissolution in aqueous NaCl solutions increased as the NaCl concentration increased. For example the total Ca concentration in 0.17V NaCl solution at a given time is about 1.5 times higher than the concentration in water. Thus, when gypsum is used as an amendment in the reclamation of sodic soil and sodic water, the rate of dissolution of gypsum will change according to the concentration of NaCl in solution (in addition to the common ion effect when Ca2+ and/or SO4~ ions are present).

2) The dissolution coefficients of the analytical, industrial, and mined gypsum are the same for a given surface area. However, the surface area (at a given fragment size) of the industrial gypsum is larger than that of the mined gypsum (for a given amount) and , therefore, the dissolution rate is higher. As the fragment size of the gypsum becomes smaller, the difference between dissolution rates of both sources decreases.

3) The infiltration rate of sodic soil exposed to simulated rain depends on the source, amount, and size of the gypsum fragments used. The efficiency of gypsum in maintaining a high infiltration rate correlates with its rate of dissolution. Industrial gypsum is more effective than mined gypsum in maintaining a high infiltration rate.

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