Tolerance of Acacia nilotica to sodium adsorption ratio enriched brackish irrigation water at early growth stages

A field trial of Acacia nilotica (Linn.) Willd. ex Delile was conducted in polythene lined micro-plots to evaluate its tolerance to Sodium Adsorption Ratio (SAR) of irrigation water at early growth stages, using varying qualities of artificially prepared sodic water (SAR 5, 15, 25, 37.5 and 50) for irrigation on sandy loam soil (Coarse-loamy mixed hyperthermic Ustorthents). The best available canal water having EC 0.2 dS/m (SAR 0.17) was used as control. Acacia nilotica grew well with stunted growth at SAR 50 level. However, the 50% reduction in biomass yield of Acacia nilotica as limits of tolerance was observed at SAR 35.4. Uptake of Na+ by plants increased progressively with increase in SAR levels, whereas the uptake of Ca2+ decreased. Mg2+ uptake in general, increased but did not show any constant relationship. Higher uptake of Na+ influenced the uptake of nitrogen, phosphorus and potassium.