Keywords: 
• coral sand /
• backfilled soil /
• water content /
• Scaevola sericea

Abstract: The dredger filled land in the tropics is mainly composed of coral sand accumulated without native ecosystem. Man-made vegetation and ecological systems need to be constructed to create a livable ecological environment for the production and living of the people living in the dredger filled land. Coral sand contains very low water and it is difficult for plants to survive and grow on it. It is necessary to study the water content of coral sand and the change of water content in the coral sand when planted with Scaevola sericea, which is significant to make the planting and water management schemes in the backfilled land with coral sand. The results showed that the water content of coral sand above 50 cm deep ranged from 6.1% to 10.9%. After 7 days of planting, the water content of the soil in the backfilled land was 9.4% for coral sand, 14.5% for mixed soil, and 31.6% for organic soil,while the water content of coral sand was falling from 17.6% to 13.0% in the second day and then maintaining at about 10%. The results proved that as the site condition of cultivation, the coral sand mixed with organic manure and yellow loam can improve the water content and water retention capacity of the backfilled soil, which is beneficial to improvement of the survival rate of plants cultivated and water utilization rate.