Conclusions
We evaluated the dynamic changes in SWC and ST during freeze-thawing in agricultural soils. During the study period, the freezing point and water migration as well as the distribution of SWC changed significantly. The initial SWC distribution seemed to control the upward water movement. The lowest ST was -18.92℃ and occurred at depths above 20 cm, while the highest SWC (19.79%) occurred at a depth of 80-100 cm. During freezing, the temperature affected the freezing front, resulting in a more rapid thawing process compared to the freezing process. Before the ST dropped to the freezing point, upward soil water migration caused a slight decrease in SWC in each layer. In general, freeze-thawing is affected by changes in water potential energy and pore pressure gradient, resulting in the migration of soil water to the upper layers. In addition, during the entire freezing process, the upper soil (0-60 cm) was significantly affected by temperature changes, and its ST levels and water content fluctuations were significantly stronger. Affected by freeze-thawing, the soil texture and physical properties will be greatly changed, the soil compaction will be reduced, and the soil particles will be more broken. This, in turn, increases wind erosion and the frequency of dust events in semi-arid agricultural areas, which might also alter carbon and nitrogen cycles. Soil thawing increased soil water storage in farmland, reducing reliance on irrigation. Our results provide a deeper understanding of soil freeze-thawing processes in semi-arid agricultural areas and their impacts on crops, facilitating the development of adequate management strategies.