Rationalizing the Use of Water of Salinity Hazards for Irrigating Maize Grown in a Saline Sodic Soil

SOILS of Fayoum depression are mostly salt affected and usually irrigated with water of EC around 1.2±0.2 dS m-1. The current research was conducted to investigate the effects of gypsum, organic manure and humic acid applied to a saline sodic clay soil (EC 5.7 ±0.1 ) singly or in combinations under two irrigation systems (furrow and drip systems) at two levels of irrigation (100% of the water requirements (WR) and 75% of WR) on water saving in relation to maize productivity. The results indicated that amendments significantly increased grain yield; more upon using each singly than in combination. Increases were more pronounced with increasing the amount of irrigation water from 75% of the WR to 100% of WR. Grainyield was significantly higher in the second growing season than the first one which means a successful sustaining production of maize in the area of study. Protein content in grains ranged from 144.2 to 163.7 g kg-1 which is higher than the protein content of the maize imported by Egypt from other countries. Virtual water values (VWV) ranged between 0.60 to 0.89 m3 kg-1 grains under drip system which was superior in the efficiency of using water for producing crop yield than values of 1.00 to 1.52 m3 kg-1 under the furrow system.