Soil Salinity Spatial-temporal Variation And Salinity Transport Simulation In Southern Laizhou Bay

As one of the low-yielding soil types, saline soil plays an important role inagricultural science and soil science, and it directly related to the level of cropproductivity. Using classical statistics and geo-statistics to study the characteristicsand distribution of soil salinity based on systematic grid sampling in southern Laizhoubay during2012, gave a first assessment, and explored the salinity transportation ofthe saline soil located in this study area by conducting the salt-leaching experiment.The main conclusions were drawn as following:Firstly, soil salinity in the study area dominated by slight and moderatesalinization, and both of them accounted for more than90%. The soil salinity hassimilar spatial distribution in the surface layer (0~30cm)，middle layer (30~60cm)and bottom layer (60~90cm), generally exhibits banded and patchy distribution, asthe highest in the north, showing higher in the middle and lower in southwest andeast of Laizhou bay. The primary factors of this phenomenon are seawater intrusionand special irrigation methods. The soil salinity in autumn is lower than in summer iscaused by the leaching of rain and the absorption of crop.While, from the difference of land use and land cover, the soil salinity shows anobvious spatial variation and increases in coin farmland, soy, grass, forest, cotton, saltland sequentially. And the soil salinity increases gradually with depth in cotton, grassand forest but decreases in soy and coin farmland. There is no obvious variation ortrend in the salt land.We also find the spatial distribution of salt ions is higher in north and the lowerin south, just the same as soil salinity. And the origin is similar to the soil salinity. Thesalt ions in this area could be divided into three categories: The first category consistsof K+,Mg2+,Ca2+and SO42-;2) Soil containing Na+is the second class;3)Which has Cl-is the third one.According to the results of salt-leaching experiment, the best scheme ofirrigation is using100m3/ha fresh water which can get the best effect. In the use ofbrackish water for irrigation in study area should keep the salinity of the water under4.31g L-1.