Abstract

                                A survey of underground irrigation water of a brackish water affected tract i Agra district of Uttar Pradesh revealed Na+-Mg++-Ca++ type waters. An increase in salinity of water was associated with increase in the concentration of the ions, however relative increase of magnesium was more than sodium and calcium. About 5 per cent of water samples were dominated with magnesium over sadium, Out of the remaining watere dominated with sodium, a large number (30 per cent) showed Na/Mg ratio between 2-3 Only 2 per cent water samples were dominated by calcium over sodium and from rem- aining sodium do ninated waters 26 per cent contained 6-10 times sodium as compared to calcium. About 94 per cent samples were dominated by magnesium ove calcium and 1/3rd of these samples analysed 2-3 times more magnesium than catcium, Hence the ratio between Na/Mg and Mg/Ca were approximately of the same order.

Key words :