Effects of chloride and sulfate onions and role of nitrogen on the physiological nutrients uptake and yield of barley (Hordeum vulgar L.)

Environmental conditions such as soil salinity, high temperature, and soil toxicity of heavy metals have harmful effects on plant growth and nitrogen uptake by roots. Fluctuations of osmotic pressure usually are related to varying chloride (Cl-) concentration. Increasing N concentration in saline soil solution may have a positive effect on the uptake of other nutrients.A factorial greenhouse experiment on barley was carried out in Ferdowsi University of Mashhad with six Cl-/ SO4= ratios (C0S0, C1S1, C1S2, C1S3, C2S1 and C3S1) and two nitrogen fertilizers (N1=75 Kg/ha and N2= 150 Kg/ ha) on the basis of a completely randomized design with three replications. The objective was to study the effects of Cl- and SO4= salinity and nitrogen on the barley physiological uptake of nutrients and yield. The results showed that maximum grain and straw yield was achieved in C1S3 and C1S2 ratios. In addition, maximum nitrogen (N), phosphorous (P) and potassium (K) concentrations were presented in straw and grain for C1S2, C1S3 and C1S1 treatments. The maximum of N, P and k concentrations under the effects of Cl-/SO4 - ratios and N resulted in low Cl- concentration and high SO4 - concentration. P uptake was not under salinity influence, which is because of the medium level of salinity used in the experiment. Maximum grain and N harvest index was observed in C1S3 and C1S1 had maximum P harvest index. The results also indicated that S harvest index was higher in high Cl- ratios (C2S1 & C3S1) because of high sulphate concentration in biomass rather than in grain under sulphate salinity.PFNUE & PFNRE (Partitial Factor N Use Efficiency and Partitial Factor N Uptake Efficiency) were maximum under high SO4= and low Cl- concentration (C1S3 and C1S2) treatments, but not for PFNUTE (Partitial Factor N Utilization Efficiency). Hence, maximum of PFNUTE was related to high Cl- and low SO4 - concentrations (C3S1 and C2S1) because of the antagonistic effect between SO4= and NO3- . The trend of PFNUTE, PFNUE & PFNRE was similar in two N levels (75 and 150 Kg/ha) and PFNRE was double for 75 Kg N /ha relative to 150 Kg N/ha.