Effect of Increasing Levels of Residual Sodium Carbonate in Irrigation Water on the Exchangeable Sodium Percentage of a Sandy Loam Soil and Crop Yield

Sodic waters of fixed sodium adsorption ratio (SAR) (16) and total soluble salts (25 m.e./l), but increasing residual sodinm carbonate (RSC) levels (0, 2.5, 7.5 and 12.5 m.e./l) were used in wfieat-bajra (pearl millet) rotation on a sandy loam soil in lysimeters, for three years. The total amount of irrigation water applied and rainfall received during the entire study period was 225 and 240 cm, respectively. Maximum ESP build up did not exceed 50% of SARiw in zero and 2.5 RSC,whereas it was 100 and 120% of the SARiw under 7.5 and 12.5 RSC treatments. The straw and grain yield of wheat were not affected significantly. Bajra fodder yield decreased consistently with rise in the RSC of water and was reduced to 50% at a soil ESP of 15 and pH of 9.0