| Abstract: |
Optimum fertilization management is an important technique to alleviate the adverse effects of salinity stress on plants. A pot experiment was conducted to evaluate the ameliorative role of inorganic and organic P-sources on wheat grown under salt stress in three soil types deficient in available P. Wheat plants (Triticum asetivum L. cv. Shakha 93) were grown on alluvial, sandy and calcareous soils under salinity levels of 4, 8 and 12 dS/m of saturated paste extract (ECe) and supplied with constant rate of 30 mg P2O5/kg soil as superphosphate (SP), cattle manure (CM) and 1:1 mixture of SP and CM , beside 0 P as control.The results revealed that plants grown on the sandy soil were more susceptible to the adverse effects of salinity compared with that planted on the alluvial one, especially at 0 P. However, plants grown on the calcareous soil were moderately affected. In addition, varying soil type caused significant differences in the aboveground biomass and uptake of N, K, P and Zn in shoots and grains, where maximum values were attained in the alluvial soil followed by calcareous soil. Grains and straw yields and contents of N, P and K in the shoot tissue, grains and straw decreased significantly with increasing ECe from low (4 dS/m) to high level (12 dS/m). In contrast, increasing ECe slightly increase Zn concentrations and induced significant increases in Zn uptake in the aerial parts of wheat plants. It was obvious that P ameliorated wheat growth under salt stress, and this role was greater under moderate and high salinity. The increases in N, P, K and Zn uptake appeared driven by P application were more conspicuous in the sandy and calcareous soils. Results also indicated that combined application of inorganic and organic P-sources treatment surpassed both when each applied solely, and this was true under all tested soil types and salinity levels.
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