Effects of water quality and frequency of irrigation on growth and yield of barley (Hordeum vulgare L.)

A field trial on a loamy sand soil was carried out to study the effect of three irrigation waters with different qualities on growth and yield of ‘Gesto’, a barley (Hordeum vulgare L.) cultivar. Three irrigation water quality treatments (canal irrigation water, drainage water, and mixed canal and drainage waters at 1:1 ratio) were imposed with two irrigation frequencies (I and 2 week intervals). In addition, nitrogen and phosphorus fertilizers were applied at different rates. Barley grain and straw yields were significantly decreased under the use of drainage water (EC 10.7–16.7 dS m^?1), attributed mainly to reduction in the number of spikes per plant and grain weight. The mixed irrigation water (EC 6.8–9.9 dS m^?1) produced high seedling emergence and good vegetative growth, which was followed by high grain and straw yields. These yields were not significantly different from those under fresh canal irrigation water (EC 2.8–3.9 dS m^?1). Thus, mixed water could be another alternative for irrigation under similar experimental conditions especially with high rates of nitrogen (250–350 kg ha^?1) and phosphorus (90 kg ha^?1) fertilization at weekly irrigation intervals, which could eventually save more fresh irrigation canal water for other cultivated crops.