Evaluation of Sustainable Cropping Sequences for Ameliorating Saline-Sodic Soil with Amendments and Water Having Different EC to SAR Ratios

A pot experiment was conducted on saline-sodic soil following sorghum-oat and rice-wheat crop rotations and amending with gypsum (G), farm manure (FM), and mulch (M). Water of different qualities viz. electrical conductivity (EC) 0.6 + sodium adsorption ration (SAR) 6, EC 1.0 + SAR 12 and EC 2.0 + SAR 18 was used for irrigation. The results showed that one pore volume (PV) of brackish water with higher EC and SAR ratio may be used beneficially, if proper amendments are applied. For rice and oat crops, the order of effective amendments was G>FM>M>control (C). With sorghum and wheat, the order was FM>G > M > C. Salt removal from soils was the lowest when leaching fraction (LF) was 0.20 and was the highest when LF was 0.32, i.e. a direct positive relationship. This proposes that irrigation water and the salt accumulated in the profile should be measured after short intervals to avoid reoccurrence of salinity.