Effect of saline and alkali water irrigation on physical and chemical properties of sodic clay loam soil

Abstract

"Presence of appreciable amount of soluble salts has a deleterious impact for raising salinity/ alkalinity in semiarid and arid regions. We evaluated the effect of varying saline and alkali waters on physical and chemical properties of alkali soil which has characteristics of soil pH of saturation paste, electrical conductivity of saturation extract and exchangeable sodium percentage (ESP) of 8.75, 4.98 dSm-1, 31.2%. Soil were sequentially leached in a constant head method using 1 litre volumetric flask and cores with normal (T1), saline water at 5.0 (T2) and 50.0 (T3) me L-1 of total electrolyte concentration (TEC) at a fixed SAR of 2.5 mmol1/2 L-1/2 with Ca:Mg ratio of 2:1, alkali water having residual sodium carbonate (RSC) of 1.0 (T4) and 5.0 (T5) me L-1 with Ca:Mg ratio of 2:1, respectively. Incoming solution of concentrated saline water (T3) has a favourable influence for upkeeping soil hydraulic properties among the simulated saline and alkali water. Increase and decrease in pH2 of soil water suspension revealed that both Ca2+ and Mg2+ build up and displace from exchange sites due to continuous application of normal and saline water, respectively. Residual carbonate and bicarbonate loading in incoming water aggravated alkalinity build up in soil when it was percolated with RSC water with varied quality. Abundance of HCO3 - and CO3 2- in alkali water caused the complete precipitation of the divalent Ca2+ and Mg2+ and increased the ESP to very high values"