The researchers studied how salt moves in sandy soil when water is added. They used a lab experiment with soil columns to observe how salt moves in sandy and mixed soils when water is added. They found that after watering, salt from the surface soil dissolves and moves down, forming a peak of salt in lower layers. The salt peak forms later in deeper soil. After reaching a peak, the salt levels decrease rapidly, leading to a desalting stage. The soil's salt levels eventually stabilize. In sand-free soil, the highest salt levels were at 90 cm deep after 84 hours, while in sand-layered soil, it was at 70 cm. Over time, the salt peak moved deeper into the soil. This study helps understand how to improve and use alkaline soil near the sea.