The effect of the type of irrigation with the combination of purified wastewater and salt water on the absorption of some heavy metals in barley seeds

Lack of water resources and rainfall are among the problems facing agriculture in hot and dry regions. The experimental factors included irrigation level (100, 70, and 50% of water requirement) and water type (separate, mixed, and mixed irrigation with treated wastewater and saline well water) in three replicates. Land preparation and cultivation of barley seeds were done in the agricultural lands of Birjand wastewater treatment plant , and after the harvest, the barley seeds were separated and digested, and the concentration of manganese, aluminum and arsenic was measured. The results showed that the concentration of arsenic in barley was insignificant in all treatments and the range of changes of manganese was between 68.4 and 96.5 and aluminum was between 39 and 115.2 mg/kg, which is in accordance with the animal feed standard. In this regard, the concentration of manganese and aluminum in the irrigation treatment was 79.4 and 53.7, respectively, and in the mixed irrigation treatment it was 78.3 and 52.1 mg/kg, and no significant difference was observed between them at the statistical level of 5%. Lack of irrigation in all treatments caused an increase in manganese accumulation and in all treatments except irrigation with treated wastewater and intercropping irrigation caused an increase in aluminum absorption in seeds. By changing the irrigation regime from 50% of water requirement to 100%, the role of water salinity in the accumulation of metals decreased and the role of treated wastewater organic matter increased. The results of this study in terms of the effect of irrigation water level and the punitiveness of one-in-one irrigation and mixing with purified wastewater and salt water in reducing the accumulation of heavy metals in barley grain, as two low-cost management solutions, are a good guide in the safe use of these unconventional waters. is in agriculture."