Effects of Treated Wastewater Irrigation on the Growth and Yield of Three Maize (Zea mays L.) Varieties in the Mining Area of Arlit, Niger

Abstract

Arlit, a mining city in northern Niger, faces severe water scarcity because of its arid climate and substantial water demand. Reusing treated wastewater for irrigation may provide an alternative water source for crop production under these conditions. This study compared the growth and yield-related responses of three maize (Zea mays L.) varieties—Jaune de Tassaou, Rouge de Gayi and Maka—irrigated with treated wastewater or fresh water. A randomised complete block design with three replications and six treatment–variety combinations per block was used. Fourteen phenological, growth and yield-related traits were measured, and the data were analysed using analysis of variance and principal component analysis. Irrigation water type significantly affected flowering, all measured growth traits and all evaluated yield components. Treated wastewater shortened the periods to male and female flowering and increased leaf length, leaf width, stem diameter, number of nodes, ear length, ear diameter, cob weight, stem biomass, grain number, total grain weight and 100-grain weight relative to fresh water. Total stem biomass and grains per row increased by 45.31% and 20.64%, respectively. The first principal component explained 30.41% of the total variation and distinguished the two irrigation treatments. The findings indicate that treated wastewater may support maize production under the water-limited conditions of Arlit, although its use requires regular assessment of water quality, soil conditions and potential contaminant accumulation.