Abstract

The wetland farms in the Wammakko region of Sokoto, Nigeria have been experiencing an increase in stunted growth of plants, reduced yield, burnt leaf tips and visible accumulation of whitish residues on the topsoil, all of which are pointers to a salt problem. This study was conducted during the dry season of August 2018 in the wetland Fadama farms, Nigeria to determine the salinity status of the soil. The experiment was conducted by dividing the chosen study area into 3 sites (based on topography, upper, middle and lower for sites A, B and C, respectively), from each site soil samples were collected at the depths of 0-15 and 15-30 cm. The collected samples were air-dried, crushed and sieved. The soil was then analyzed for particle size distribution, pH, organic carbon, total nitrogen, available phosphorous, exchangeable cations, soluble ions, cation exchange capacity (CEC), electrical conductivity (EC) at 25°C, Exchangeable sodium percentage (ESP) and sodium adsorption ratio (SAR) to aid in the salinity assessment. The analytical result revealed that the soil was predominantly silt loam with a pH range between slightly acidic to neutral. The organic carbon, total nitrogen and available phosphorous were low. The EC (25°C) was not >4, SAR was <13, ESP was >15 at 0-15 cm soil depth across sites. The soil was saline-sodic and Mg (HCO3)2 and CaCl2 were identified as major contributors to the absolute salt concentration in the study area.