Abstract
A research study was conducted to examine the crop responses of maize under two irrigation systems, i.e. raised bed and high-efficiency irrigation system (HEIS; drip irrigation) systems, with three irrigation frequencies and three levels of irrigation water quality. The trial was carried out in a completely randomised design mode with triple replication of each treatment. The raised bed irrigation system demonstrated better performance in terms of crop parameters: plant height, biological yield and grain yield for the raised bed system were recorded as 1, 5 and 21%, respectively, higher than the drip irrigation system. Field measurements for the HEIS showed that the biological yield, grain yield and harvest index were quadratically correlated with the frequency of irrigation. Better results were obtained for plots irrigated every 2 or 6 days than for those irrigated every 4 days. Good-quality water raised plant biological yield by 12% and grain yield by 14.85%. The irrigation frequency had a clear-cut effect on total dry matter weight and grain yield was dependent on the quality of the irrigated water. The raised bed with furrow irrigation system produced the highest harvest index for all of the levels of water quality and the highest water use efficiencies were observed for good-quality water. The vigorous crop growth in those plots irrigated using the raised bed irrigation system resulted from salts leaching away from the crop’s root zone; however, because it uses more irrigation water for crop production than the HEIS, this system is not preferred.