Growth and nutrient concentrations of maize in pressmud treated saline-sodic soils

An open-air pot experiment was conducted to investigate effects of pressmud (PM) on saline-sodic soil reclamation, mitigating the adverse effects of saline irrigation and increase of maize (Zea mays L.) growth. Pressmud was added at the rate of 0, 5, 10 and 20 Mg per ha to pots containing 6.8 kg air dried surface (0-20 cm) soil collected from two sites. The increasing levels of PM enhanced maize plant height, shoots and roots biomass in both soils. However, the Soil 2, with initial EC and SAR of 5.43 dS m-1 and 18.67 (m mol L-1) 1/2, respectively, produced comparatively more biomass at all PM levels than Soil 1 [silty-clay loam, EC = 6.22 dS m-1, SAR = 20.72 (m mol L-1) 1/2]. The [P] in shoots was maximum at the highest PM in both the soils but the [K] increased with PM levels in Soil 1 and decreased in Soil 2 due to the dilution effect. The Soil 1 maintained several folds more [Na] in shoots and consequently lower K: Na ratio than Soil 2. The post harvest soil pH, Na, Ca+Mg and SAR in saturation extracts decreased with increasing levels of PM as compared to control. Soil 2 released more volume of leachate as compared to Soil 1 but the leachate EC and [Na] were comparable while [Ca+Mg] were relatively higher in Soil 2. The higher removal of total salts from Soil 2 resulted in lower soil pH, EC and SAR in this soil as compared to Soil 1. The increases in crop growth with each increment of PM up to 20 Mg per ha in the present study proved the benefits of PM in increasing crop yields and suggested that doses higher than 20 Mg PM per ha could be applied to the saline-sodic soils of the area to get maximum possible crop yields depending on soil and water quality.