Improvement Effect on Different Leaching Modes of Coastal Sandy Saline Soil

The author made a simulated leaching soil column experiment on coastal sandy saline soil in laboratory,including continuous irrigation and intermittent irrigation,compared the improvement of sandy saline soil effect of different leaching modes.The experiment results show: Mineralization degree of effluent drops quickly until steady at low level as the volume changed,after continuous irrigate and intermittent irrigate,It has declined from 233.8,327.4 g/L to 2.5,2.2 g/L.Intermittent irrigation can elution more salinity with irrigated in unit water.The change trend of all ions and mineralization degree of effluent are same.Leaching efficiency declines as the irrigate water ammount rises.Leaching efficiency of 15,20,25,30 cm continuous irrigation are 2.87,2.40,1.98,1.67 g/ml,but intermittent irrigation leaching efficiencies are 3.10,2.48,2.00,1.68 g/ml.Leaching efficiency of intermittent irrigation is higher than continuous irrigation from beginning to end.The soil ions constitute has changed,because the leaching speed of every ion is different.It has changed from Na+-Cl-type to Ca2+-SO2-4 type.The leaching curve is fitted,which showed the relation between soil desalting and irrigate water ammount,and the fitting efficiency is very perfect.Leaching experiment shows that: Intermittent irrigation has a higher leaching efficiency,and the water saving potential is higher than continuous irrigation.Finally,the leaching curve can be used to guide the improvement of the sandy saline soil in the field.