Researchers conducted a field experiment in a saline-alkali wheat field to study how water and salt ions are distributed in the soil during freeze-thaw conditions. They looked at three key periods: early freeze-thaw, late freeze-thaw, and salt accumulation. Results showed that soil moisture varied at different depths during these periods, with some ions accumulating near the surface and others deeper in the soil. Soil pH and electrical conductivity also changed with depth. Overall, the study found that moisture content increased with depth after freezing and thawing, and various ions showed different distribution patterns in the soil layers.