Effect of irrigation management with saline waters on soil salinity in the crop rotation

In order to investigate the effects of saline waters on some soil characteristics، this experiment was conducted with three irrigation water salinity treatments contains 1. 7-3. 4، 8-9 and 11-12. 5 dSm-1 (low، medium and high salinity) and two irrigation water managements with four replications in a wheat-fallow-sugar beet-safflower rotation. Results show that in (1) Irrigation management with low water salinity in early season followed by medium or high saline water caused a significant decrease in ECe and SAR and meantime yield increased as compared with (2) irrigation management with medium and high saline water treatments during whole season. Wheat grain، extractable sugar in sugar beet and safflower grain yield in irrigation water management (1) followed by medium water salinity increased 26. 5، 7. 4 and 36. 4 percent as compared to irrigation water management (2) with medium salinity respectively. Irrigation water management (1) followed by high water salinity increased wheat yield by 94 percent. Sugar beet with no change and safflower with more than 100 percent yield increase. ECe and SAR changes show that irrigation management (1) followed by medium saline water of about 8 dSm-1 could relatively maintain soil solute balance، so that condition for growing semi tolerance and tolerant crops such as wheat، sugar beet and safflower maintained.