USE OF ZEOLITE TO ALLEVIATE WATER STRESS ON SUBSURFACE DRIP IRRIGATED BARLEY UNDER HOT ENVIRONMENTS

Water stress is the primary environmental factor that limits cereal production in Mediterranean environments, where barley (Hordeum vulgare L.) is one of the main crops. This investigation aimed at evaluating the effects of zeolite on barley growth under subsurface drip irrigation, subjected to water and heat stress. A sand dune soil was amended with Ca-type zeolite and irrigated every 2nd, 3rd, 4th and 5th day. The results showed that zeolite application significantly increased water-holding capacity of the soil and improved plant growth. Using subsurface irrigation with zeolite amendment helped to reduce water evaporation, kept more water in lower horizons, encouraged salt leaching, and the plants used water more efficiently. Plant growth parameters showed significant differences among treatments and were negatively affected by heat and water stress conditions. High temperatures caused accelerated evapotranspiration, water stress in plants and faster depletion of water from the root zone, causing substantial water loss and inducing water deficit conditions in plants. Using subsurface irrigation poses a better option for the reduction of evaporation and achieving higher water use efficiency. Application of zeolite together with subsurface irrigation may provide favorable conditions for crop production in water-scarce areas under warm environments. Copyright (C) 2010 John Wiley & Sons, Ltd.