Study of spatio-temporal variations of soil salinity in the south-eastern coastal part of Bangladesh

Soil salinity (SS) is one of many constraints to sustainable crop production in coastal areas of Bangladesh. With increasing the areas of saline soils in the south-eastern part of Bangladesh, it is of utmost importance to observe the variations in SS at a spatio-temporal scale. Therefore, this study attempted to assess the degree and extent of SS as well as the concentrations of ammonium acetate (NH4OAc) extractable and water (H2O) soluble cations along with anions using laboratory and GIS techniques. In connection with this, the middle part of Roypur Union of Anowara Upazila was divided into three different zones considering cropping intensity and location of sampling sites. The representative soil samples were collected from each zone in the pre-monsoon (April) and postmonsoon (December) periods of the year 2018. The results indicate distinct analytical and mapping differences in SS of the studied area in the pre-monsoon and post-monsoon seasons. The correlation of EC with all of the cations and anions was found positive in both seasons. Furthermore, the mean values of EC along with NH4OAc extractable and H2O soluble cations as well as anions of all the sampling sites varied signifi cantly (p<0.01). The fi ndings of this study successfully indicate the variations in degree and extent of the SS which would help in coping with the suitable crops to grow. Keywords