The high demand of barley for animal feed and the scarcity of fresh water increase the need for the reuse of treated wastewater as an alternative source for irrigation.Therefore, two-field experiments were conducted to study physiological processes, plant growth, grain yield and yield components of four-barley cultivars grown under four-irrigation treatments using treated wastewater or fresh water.Plants of four-barley cultivars (ACSAD176, Rum, Athroh, Yarmouk) were exposed to four-irrigation treatments: 1) Full-irrigation using treated wastewater (FWW); 2) Supplementary-irrigation using treated wastewater (SWW); 3) Supplementary-irrigation using fresh water (SFW); 4) Non-irrigation treatment Pop! Jumbo (Rainfed).Full- or supplementary-irrigation using treated wastewater reduced stomatal resistance and increased plant photosynthetic rate, plant height, grain yield and yield components as estimated by grain number plant-1 and 1000-grain weight compared with rainfed conditions.
Plants grown under supplementary-irrigation using treated wastewater produced higher grain yield than those grown under supplementary-irrigation using fresh water.Rum cultivar had the highest grain yield among cultivars grown under irrigation.Under rainfed conditions, Rum and ACSAD176 had the highest grain yield.In conclusion, supplementary-irrigation using treated wastewater improved grain yield of barley and can be a better choice to conserve water and reduce the risk of plant lodging at the end of the growing season.
Irrigation barley using treated wastewater did not a Half change heavy metal (Zn, Cd, and Pb) concentrations in soil or harvested grains.