MANAGEMENT OF SALINE SODIC SOILS THROUGH CULTURAL PRACTICES AND GYPSUM

Management of saline sodic soils requires combination of agronomic practices in addition to the chemical and organic amendments. However, the relative efficiency of the amendments under variable cultural practices is not well documented. We evaluated the efficiency of gypsum, farmyard manure (FYM) and cultural practices on the yield and yield components of wheat grown in saline-sodic soil during Rabi 2003-04. The soil under study was clay loam in texture containing 0.17% organic matter with 20.5% lime content and alkaline in reaction (pH(e) 8.8). The electrical conductivity (ECe) was 9.4 dS m(-1) with sodium adsorption ratio (SAR) of 21.4. Seven treatments viz., conventional method, Flat bed + FYM, Flat bed + Gypsum, Raised bed + FYM, Raised bed + Gypsum, Ridges + FYM, and Ridges + Gypsum were arranged in RCB design with three replications. Gypsum was applied at variable rates dependent upon the gypsum requirements of the soil, while FYM was applied @ 20 t ha(-1). Significant improvement in soil properties i.e., ECe, SAR and pH(e) was recorded in plots treated with gypsum in ridges and resulted 42% grain yield increase over conventional method. The significantly higher grain yield (3055 kg ha(-1)) may be associated with ameliorative effect of gypsum and less saline environment in ridges as irrigation next to the seed row caused movement of salts away from the seeds and into the top of the ridge. This allowed the seed to germinate and establish in less saline conditions there by increasing yield. The lowest grain yield (1781 kg ha(-1)) of wheat was produced in plots grown by conventional method. The soil samples analyzed after the termination of experiment showed that gypsum + ridges sown treatment significantly reduced the soil ECe, SAR and pHe at 0-15 and 15-30 cm soil depths as compared to conventional method. There was a positive significant relation between wheat grain yield with leaf K+ (r(2) = 0.70) while negative significant relationship between the grain yield with leaf Na+ (r(2) = 0.745). This study suggests that wheat grown on ridges supplied with gypsum was the most useful management tool in saline-sodic conditions