STUDY OF WATER QUALITY FOR IRRIGATION AT BIRGANJ UPAZILLA IN DINAJPUR DISTRICT

Abstract

A laboratory investigation was carried out to assess the suitability for irrigation purpose of 50 groundwater samples collected from different Deep Tubewells (DTW) at different locations of Birganj upazilla of Dinajpur district during irrigation period January-Aril 2017 most of the water sapless were suitable for irrigation purposes based on pH, TDS, EC, Ca, Na, K, PO4, SO4, Cl, Fe, MN and Cu content. Analyses were included pH, EC, TDS (total dissolved solids), cations (Ca2+, Mg2+, Na+, K+, Cu2+, Mn2+, Fe3+) and anions (HCO3 - , SO4 2-, PO4 3- and Cl- ). Several variables such as SAR (sodium adsorption ratio), SSP (soluble sodium percentage), Hardness (HT), permeability index (PI), Kelly’s ratio, and potential salinity to evaluate the suitability of groundwater for irrigation purpose. Almost all the water samples were within the recommended pH value for irrigation and had a great impact on crop production. 15 samples were excellent, 35 samples were good for irrigation purpose in respect to EC. For TDS all samples except 7 samples were considered as ‘freshwater’ for irrigation. Based on SAR and SSP values, all samples were classed as ‘excellent’ categories for irrigation. On the basis of Ca, K, Fe and Cu, content the entire water samples can safely be used for irrigation and would not affect the soils. Overall observation of the study was that groundwater samples were found suitable for irrigated agriculture with same exception.