Effect of saline irrigation water on the leachability of salts, growth and chemical composition of wheat (Triticum aestivum L.) in saline-sodic soil supplemented with phosphorus and potassium

Abstract

Salinity-fertility interaction has not been properly explored especially in saline-sodic soils. Therefore, the current study investigated the response of wheat (Triticum aestivum L.) to saline irrigation water in saline-sodic soil supplemented with potassium (K) and phosphorus (P). Wheat was grown in pots filled with saline-sodic soil which were irrigated either with normal or saline water. Potassium and P fertilizers were applied at two levels. Results indicated that growth of wheat plants was impaired by saline irrigation resulting in a decreased grain and dry matter yield. The P application had significant effect on the dry matter yield and other yield components. Potassium application significantly increased dry matter yield and root mass. Wheat yield increased by 14 and 7% with the application of 150 kg K2O ha-1 and 120 kg P2O5 ha-1 over the control soil under saline irrigation. The higher yield was obtained with combined P and K treatment under non-saline irrigation. The P addition significantly affected shoot and root [P] and [Na], [K] and [Mg] in the shoot tissue while the K:Na ratio produced non-significant effects under both irrigation waters. The addition of K significantly affected [Na], [K] and K:Na ratio in shoot. All other root parameters were significantly affected by the K addition. The Ca uptake by roots increased with saline irrigation. The P addition increased [P] in plant tissue. The Na uptake by root and shoot tissues was depressed with the addition of P and K fertilizers. The higher K uptake increased K:Na ratio in both shoot and root tissues. The values of EC, SAR and [P], [Na], [Ca], [Mg], [Cl] and ratios of Na:K, Ca:P, Cl:P and SO4:P in the soil leachates significantly increased with saline irrigation. The P addition had significant bearing on the soil pH, SAR, [P], [SO4], [CO3] and [HCO3] and Ca:P, Cl:P and SO4:P ratios in leachates. Saline irrigation significantly increased ECe, [Na], [K], [Ca], [Mg], [Cl], [CO3], SAR and ratios of Ca:P, Cl:P and SO4:Cl in saturated extracts of post-harvest soils. This study could suggest that the addition of P and K under saline-sodic conditions may affect salts and nutrients dynamics of the soil and was useful for crop productivity.