The treated wastewater is highly used as an alternate source of water for growing crops like sorghum for forage/fodder to livestock in Arabian Peninsula water deficit countries including Oman. In present study, high forage yielding sorghum variety, Superdan was investigated under three irrigation systems (Surface, Sub-surface and Drips) at Agriculture Research Station, Rumais, Oman, for its response to treated wastewater and fresh water irrigation conditions with respect to forage productivity. Study was conducted over continuous 11 forage harvests which started from summer season (April, 2013) and completed in mid-winter season (March, 2015). The results of study revealed that both mean green and dry matter yields/ cut and their total yield over 680 days were significantly higher under drip irrigation and it was followed by sub-surface and surface irrigation systems in both treated and freshwater irrigations. Water use efficiency (WUE) of sorghum was significantly higher under drip irrigation than under other irrigation systems not only with treated wastewater (2.54) but also with freshwater irrigation (2.49). The concentrations of heavy elements were either very low, low or in trace amount under the limits of toxicity threshold in both plant samples and soil samples. The present study demonstrated that forage sorghum can last till 11 cut-harvests spanning 680 days providing total green and dry matter yields of 508.30 t/ha and 143.88 t/ha respectively under treated wastewater irrigation compared to total green and dry matter yields of 498.26 t/ha and 144.58 t/ha, respectively under freshwater irrigation.