The study aimed to assess the effects of using rice husk ashes to treat the quality of non-fresh irrigation water on the growth and productivity of the wheat cultivar Al-Rashid in plastic pots. The research occurred during the 2022–2023 season at the Thi-Qar Governorate, Iraq. The randomized complete block design with split-plot arrangement had two factors and three replications. The main plots were the irrigation water quality (W), comprising river water 2.1 dSm^-1 (W1), city sewage water 6.4 dSm^-1 (W2), and drainage water 12.3 dSm^-1 (W3). The subplots were the ashes of rice husks (T) burned at temperatures of 1000 °C (T1), 800 °C (T2), 600 °C (T3), and 400 °C (T4). The burned rice husk (T1) showed a significant positive effect on the growth and yield traits, i.e., plant height, leaf area, tillers per plant, grains per spike, and grain yield (113.67 cm, 62.86 cm², 9.73 tillers plant^-1, 65.22 grains spike^-1, and 7.438 t ha^-1, respectively). Drainage water caused a decrease in average values of studied traits compared with the river water. The river water exhibited a significant positive effect and provided the highest means for the above traits (118.42 cm, 63.66 cm², 10.32 tillers plant^-1, 71.58 grains spike^-1, and 7.967 t ha^-1, respectively). The interaction of river water (2.1 dSm^-1) and burned rice husks (1000 °C) (T1 and W1) gave the maximum grain yield (8.212 t ha^-1).

Keywords: Wheat, lack of water revenues, rice husk ashes, irrigation water quality, growth and yield traits

Key findings: The study revealed that increasing the temperature of burning rice husks to treat irrigation water can improve the mean values of studied traits.