Effects of Irrigation Water Salinity and Leaching Fraction on Soil Chemical Characteristic, Grain Yield, Yield Components and Cation Accumulation in Safflower in Esfehan



In order to study the effects of irrigation water salinity and leaching fraction on soil chemical characteristic, grain yield, yield components and sodium and potassium contents in leaves of safflower, an experiment was coducted in a split plot design with four replications in 2009 at Roudasht, Isfahan. Treatments included three irrigation water salinities of Q1=3.35, Q2=8.77 and Q3=11.21 dS/m in main plot and two leaching levels, LR0=without leaching and LR1= leaching fraction based on 75% grain yield of safflower in sub plot. Results showed that by using leaching fration, SAR value and the amount of sodium ions reduced, especially at the 30 cm soil depth. Reduction in sodium content in the depth of 0-30 for 3.35 and 8.77 dS/m were 2.9 and 11.1%, respectively. Salinity significantly reduced grain yield of safflower and with rising salinity levels from 3.35 to 11.21 dS/ m, grain yield declined about 67.4%. The main effect of salinity on yield components was found on the biomass production which was reduced by 71% at 11.21 dS/m compared to 3.35 dS/m. This ultimately reduced the percentage of harvest index. Although using leaching fraction increased grain yield of safflower but interaction of salinity and leaching had significantly decreased harvest index and biomass production, but did not have significant effects on grain yield and other yield components. In this study, salinity significantly affect absorption of sodium and potassium. At 11.21 ds/m the amount of absorption of potassium 28.2% decreased and 63.5% of sodium absorption in safflower leaves was increased. The leaching treatment and interaction between salinity and leaching did not have significant effect on the absorption of these two elements.