Conjunctive Use of Saline Ground Waters for Crop Production in a Semi-arid Climate

A field study was conducted on a sandy loam calcareous soil to evaluate the effect of conjunctive use of two saline ground waters [EC_i=4 and 8.5 dS m⁻¹; SAR 18-9 and 21.6 (mmol L⁻¹)^½] along with organic matter in different modes on soil salinity build-up, growth and yield of wheat and succeeding cluster bean. Both crops were given a pre-sowing irrigation with 4 dS m⁻¹ salinity water. Subsequently, the wheat crop was irrigated four times in different sequences of two saline ground water. The rainy season cluster bean received only one irrigation, as there was suficient soil moisture available due to monsoon rains. The results of this study indicated that grain yield of wheat decreased with the increase of irrigation water salinity. Taking wheat yield obtained with best saline water irrigation (EC = 4 dS m⁻¹) as the potential value (100%), the mean relative grain yield of wheat irrigated with high salinity (EC = 8.5 dS m⁻¹) water was 80%. Substitution of best available saline water at first post-plant irrigation and applying thereafter only high salinity water increased the yield to 85.5%. Conjunctive use of best available saline water with the high salinity water in different treatment resulted in 86.6 to 91.2% yield. The succeeding cluster bean crop yield did not decrease significantly in any of the previous irrigation treatments. Application of farm yard manure, @ 10 t ha⁻¹ during rainy season increased the grain yields of both the crops significantly.