The Effect Of Different Leaching Way On Improvement Of Coastal Saline Soil

Irrigation leaching has been one of the important ways of improve saline soil. This study involved leaching efficiency and water saving potential to compared two leaching ways to improve coastal saline soil. The objective is to select the best leaching way for different coastal saline soil. There are two levels of irrigation leaching way:continuous leaching and intermittent leaching. The results show that the mineralization degree of effluent drops quickly until steady at low level as the volume changes, intermittent leaching can dissolve more salinity than continuous leaching. The change trend of all ions and mineralization degree of effluent are same. The salinity of soil column drops significantly after leaching. The soil ions constitute has changed from Na+-C1-type to Ca2+-SO42-type. In the experiment of sandy soil, The leaching efficiency are2.87,2.40,1.98,1.67g/cm after continuous leach15,20,25,30cm water, and the intermittent leaching efficiency are3.10,2.48,2.00,1.68g/cm. The leaching efficiency of intermittent leaching is higher than continuous leaching from beginning to the end. Both the intermittent leaching and the continuous leaching can be used to guide field working thought intermittent leaching has some of the water saving potential. The leaching curve can ascertain the leaching quota. In the cohesive soil experiment, The leaching efficiency are1.58,2.19,1.66g/cm after15,25,35cm continuous leaching, but the intermittent leaching efficiency are1.78,2.28,1.72g/cm. The intermittent leaching saves about27%and it will be higher after increase9t/hm2-sulfur-removal gypsum. So the intermittent leaching and fertilize9t/hm-sulfur-removal gypsum are the best way to guide the cohesive soil field working.