اثر چهار رژیم تلفیقی آبیاری با آب شور بر الگوی توزیع شوری خاک در شرایط کشت گیاه

The main objective of this study was evaluation of integrated management and mixing saline/fresh water on soil salinity distribution. For this purpose, a field was selected and 32 plots were made in it with a 6 m×2.5 m size. A split plot experiment was employed with two sunflower varieties (Alstar and Hisan33), four irrigation schemes (CIS) and four replications. Irrigation schemes being applied as treatments are: T1: every other irrigation with saline water (11 dS m-1) and fresh water (2 dS m-1) (every other irrigation), T2: fresh water - saline water, T3: mixed irrigation and T4: saline water - fresh water. Soil samples were collected from depth of 0-20, 20-40 and 40-60 cm in the early, mid and end of the irrigation season. The samples were analyzed for EC, Ca, Mg, Na and Cl. The result showed that soil salinity in depth of 40 cm is greater than salinity in depth of 20 and 60 cm in all treatments and for both sunflower varieties, in all growing stages. The maximum salinity concentration was observed in T2 among all treatments. Increasing irrigation depth has increased the soil extract’s Cl and Na in all treatments during growing season to 50 and 75 meq/L, respectively. The effects of CIS treatments are statistically significant on Ca and Mg in Alstar, and in all regimes affect on different depths. The minimum value of EC and maximum yield was observed in T4, T3, T1 and T2, respectively.