Effects of Covering Sea Ice on Platform Field on Soil Water and Salt Content in Coastal Saline Soil of Bohai Bay

Based on the building technology of platform field,sea ice was covered on soil surface of the field in Bohai Bay of China,because sea ice had lower salts than seawater in winter.The change of soil water and salt in melting processes of sea ice was determined at different stages.The present studies showed that the large amount of ice-melting water infiltrated into the soil and increased soil water content at all depths,especially top soil(0-20 cm).In later stages,soil water content of 0-40 cm layer was reduced with increasing of air temperature and value of other soil layers stabilized.At March 8,soil salt content of 0-20 cm and 20-40 cm layer were lower 70% and 22.22% than the value at primary time,whereas soil salt content of other layers slightly increased.At March 14,sea ice was completely melt and soil salt content of all layers continued to decrease in platform field.During later sampling stages,soil salt content of 0-20 cm and 20-40 cm layer stabilized(1.5~2.0 g/kg and 3.5%,respectively) and soil desalting rate of them was 80%~85% and 22.22%,respectively.While soil salt content of deeper layer had no changes compared to their value of primary time.These results indicated that the combination of platform field and covering sea ice on soil surface decreased 0-40 cm layer soil salt content and there was no salt accumulation in deeper soil layers.