To explore the changes of pore and unfrozen water contents in saline soils during the freezing-thawing process

the pore and unfrozen water contents in different saline soils and NaCl saturated soil samples were determined using nuclear magnetic resonance spectrometer (NMR) to detect

the effects of soils texture on unfrozen water content in freezing process were studied

and the hysteresis during the freezing-thawing process was analyzed. Eight treatments were designed

i. e. two types of soils (mild saline silt loam and moderate saline loam) and four types of solutions (distilled water

0.2% NaCl

0.6% NaCl and 1.0% NaCl ). The findings were as follows: (1) macropores showed a faster decrease in unfrozen water content than micropores during the process of salinized soil freezing

with the thawing dissolved first in micropores in salinized soil. (2) For both the light and moderate salinized soils

unfrozen water content was the maximum when the soil were treated with 1.0% NaCl solution. (3) As could be seen from the comparison of unfrozen water content between different soils during the freezing-thawing process

the loam had higher unfrozen water content than in the silt loam. According to the experimental results

water content reduction started in macropores

while water content increase started in micropores during freezing-thawing process. The higher the concentration of NaCl solution was

the larger the unfrozen water content was

and the lower the freezing temperature was. Unfrozen water content changed to varying degree in different soils

and the unfrozen water content in the loam was obviously higher than that in the silt loam; saline soil frozen and thawed relatively slowly

and in the areas where freezing and thawing lagged behind obviously

the temperature range tended to decrease with the rising concentration.