the Southwest Sokoto-Rima Basin, Nigeria.

Ground water from open-wells, tube-wells and boreholes were investigated to ascertain the current quality status and suitability for irrigation in the floodplains (Fadama lands) of the southwestern Sokoto-Rima basin in northern Nigeria. The water samples were slightly acid with pH values ranging from 5.7 to 6.1. In terms of salinity hazards measured as electrical conductivity (Ecw) and total dissolved solids (TDS), the water samples had very low salinity (Ecw 48-607 uS.m-1, TDS 38-486mg.l-1) with the exception of the tube-well samples from site C (Birnin Kebbi) with moderate salinity (Ecw 822 uS.m-1 and TDS 657 mg.l-1). With respect to sodicity hazards, the sodium adsorption ratio (SAR) values obtained for all the samples ranged from 0.2 to 1.4. This indicates a low risk of sodium buildup in the soils. However, irrigation water of very low salinity (<200uS.m-1) and low SAR can lead to problems of water infiltration into the soils. The nitrate concentration in most of the samples was quite high ranging from 4.5 to>50mg.l-1, possibly as a result of excess applications and leaching of nitrogen fertilizers