Reuse of Agricultural Drainage Water for Crop Production

A field experiment was conducted for two years on a sandy loam soil to evaluate the effects of irrigation with drainage water of different salinity levels (EC_iw = 3,6,9 and 12 dS m⁻¹) on soil salinity build-up, growth and yield of wheat and succeeding pearl-millet and sorghum crops. Drianage water (EC=12–12.5 dS m⁻¹) was blended with canal water (EC =0.5 dS m⁻¹) to obtain different EC levels. On an average, use of 3, 6, 9 and 12 dS m⁻¹ salinity waters for two years resulted in 8.6, 19.7, 27.5 and 43 per cent reduction in wheat grain yield, respectively, as compared to the yield with canal water irrigation. Pearl-millet and sorghum yields decreased significantly only where 9 and 12 dS m⁻¹ salinity water was applied to previous wheat crop. Increased soil salinity and sodicity hazards were eliminated by the subsurface drainage during the ensuing monsoon periods.