Removal of salinity from soil surface by a water-saving leaching method

摘要

Salt accumulation occurs in a very thin soil surface layer and in a spot state in an early stage.In this stage,leaching should be conduct for only the salt accumulation zone.Surface Suction Leaching Method(SSLM)developed by authors,can do such salt removal using a little water.An instrument for SSLM consisted of three parts-water supply,drainage and insert parts.The water supply part had a storage tank for leaching water and a flowing pump.The drainage part had a vacuum pump and a collection tank for soil water.The insert part was a disc-shaped container with a stainless guide for inserting into soil,a ceramic filter,and an inlet/outlet pipe with a bidirectional cock.It was directly inserted into a salt accumulated zone on soil surface.Through the cock,the inlet/outlet pipe was connected with the water supply and drainage parts,respectively.An operator could select the stages of water supply for leaching and collection of soil water for removal of salts by changing the cock.In this study,the method was applied into sandy soil with artificial salt accumulated soil layer with 15 Ds/m.As results.The process could remove 80％of accumulated salts and collect 93％of leaching water from the soil layer.SSLM was thus a useful water saving desalinization method.