UTILIZATION OF SALT AFFECTED SOILS FOR WHEAT-RICE PRODUCTION IN ARID REGION OF EGYPT

A field experiment was conducted on a salt affected soil at Hussienia south plain, Sharkia Governorate, during two successive seasons winter 2008/2009 and summer 2009 to evaluate the effect of soil amendments i.e., gypsum and sulfur applied individually or combined with different nitrogen sources i.e., urea formaldehyde, urea and ammonium sulfate at three rates 75 %, 100% or 125 % N from  the recommended dose for wheat plants. Rice was grown in the same plots without any further application of the aforementioned soil amendments to study their residual effects on straw and grain yields as well as uptake of N, P and K. Results showed that the soil amendments significantly improved the straw and grain yields of wheat as well as N, P and K uptake by both straw and grain compared to the control treatment.  Also, it was found that straw, grain and N,P and K uptake by plants increased with increasing rates of nitrogen sources application and the highest values were achieved at a rate of 125 % N from the recommended dose. The combination between soil amendments and nitrogen sources produced higher values of straw, grain yields and N, P and K uptake values, compared to the soil amendments or nitrogen sources alone and the control. The highest values of straw and grain yields as well as N,P and K uptake by wheat plants were recorded by the combined application of urea formaldehyde at a rate of 125% from  recommended dose + gypsum. Concerning the residual effect of soil amendments, the results revealed that the straw and grain yields as well as N, P and K uptake by rice plants were significantly enhanced with the application of nitrogen fertilizer combined with the residual effect of the used soil amendments. However, the higher values of the abovementioned parameters were obtained due to the residual effect of sulfur combined with nitrogen fertilizer. The soil samples analyzed after both wheat and rice harvesting showed that the residual effect of gypsum or sulfur significantly reduced the soil ECe, ESP and pH. From the results, it could be recommended that the application of 125% N from recommended dose especially in the slow release combined with soils amendments were required for wheat and rice grown on new reclaimed salt affected soils as well as reduced soil ECe, ESP and pH.