Interaction of Phosphorus and Potassium on Maize (Zea mays L.) in Saline-Sodic Soil

Salinity and nutrient deficiencies are the main constraints for high crop productivity. Interaction of diammonium phosphate and potassium sulphate in saline-sodic soil for maize (Zea mays L.) crop was investigated. The results demonstrated that maize responded well to K and P fertilization in saline-sodic soils. The effects of salinity and sodicity were ameliorated by the application of K and P fertilizers resulting in higher yield. K had greater influence on grain yield than P level. K application increased yield related parameters. The addition of P significant affected leaf [P] and [Na] content, Na:K and Ca:Na ratios. Potassium levels had significant effects on [Na], [K], [Mg] and Na:K ratio. Phosphorus and K interactions did not affect leaf chemical composition except Mg content. The P application resulted in an increase of [P] in maize leaf tissue as compared to control. A decrease in [Na] and Na:K ratio was observed with the addition of K. There was positive relationship between grain yield (R2 = 0.67), dry matter yield (R2 = 0.76) and leaf [P], respectively in soils treated with P. The tissue [Ca], ratios of Ca:K and Ca:P were non-significantly affected by the K and P treatments. Extractable [P] increased after P treatments in the soil. The application of K significantly decreased Na:K ratios in the soil. Th