When using gypsum, the particle size of the gypsum used must be considered. Smaller gypsum particles dissolve faster. Of course, given the cost of this work, the size choice depends on economic issues, and this does not mean that the use of powder agricultural gypsum can have the best result in all cases. Gypsum particles smaller than 2 mm, with a wide distribution of particle size, can well release calcium and displace sodium without precipitation through the ion exchange processing.
The limited solubility of gypsum in water (2.4 g L-1) reduces soil reclamation speed. Larger gypsum particles can cause better water infiltration in the soil before dissolution. Powder gypsum can be easily dissolved in irrigation water at pond or the basin, and the water containing dissolved gypsum enters the soil evenly. This method is more effective in fields with medium and low sodium content. For instance, if the water in the pond is saturated with gypsum, using 1000 m3 of irrigation water, equal to 2.4 tons of pure gypsum has entered the soil. Also, gypsum is available in soluble and usable in pressurized systems.