2158 Advances in Environmental Biology, 6(7): 2158-2163, 2012 ISSN 1995-0756 This is a refereed journal and all articles are professionally screened and reviewed ORIGINAL ARTICLE Corresponding Author Khosro Estaki Oregoni, Ph.D student of Soil Science, Science and Research Branch, Islamic Azad University, Khouzesatn, Iran, E- mail: khesteki471@yahoo.com Effects of Treated Low Quality Wastewater on Growth Parameters of Young Zard Olive (Olea. europaea L.) Cultivar in Different Irrigation Conditions 1 Khosro Estaki Oregoni, 2 Ebrahim Pazira, 3 Payam Najafi, 4 Abdol Amir Moezi 1 Ph.D student of Soil Science, Science and Research Branch, Islamic Azad University, khuzesatn, Iran 2 Faculty of Agriculture and Natural Resources, Science and Research Branch, Islamic Azad University, Tehran, Iran 3 Faculty of Agriculture and Natural Resources, Islamic Azad University, Khorasgan, Iran 4 Faculty of Agriculture and Natural Resources, Ahwaz University, Iran Khosro Estaki Oregoni, Ebrahim Pazira, Payam Najafi, Abdol Amir Moezi; Effects of Treated Low Quality Wastewater on Growth Parameters of Young Zard Olive (Olea. europaea L.) Cultivar in Different Irrigation Conditions ABSTRACT This study was carried out to investigate the effects of using treated low quality wastewater on the vegetative growth, leaf water contents, total chlorophyll and nutrients content of three years old zard olive (Olea. europaea L.) trees.The experiments were carried out for 3 years (2006 – 2009) in random complete blocks in three treatments with six repetitions. The treatments were: subrface drip irrigation with wastewater (T 1 ), subsurface drip irrigation with wastewater in 15 cm depth (T 2 ) and subsurface drip irrigation with wastewater in 30 cm depth (T 3 ). Wastewater from the treatment plant of the Khoramabad, Iran was used. Results indicated that, subsurface drip irrigation with wastewater in 30 cm depth as compared to other treatments had higher growth parameters, nutrients content and had seen significant difference. Thus, drip irrigation T 1 with wastewater, had lower growth parameters as compared to another treatments. In T 3 , plants absorb water and essential elements, better than other treatments because irrigation source is near the root zone. Key words: essential elements, olive, surface drip irrigation, wastewater Introduction As demand for fresh water intensifies, wastewater is frequently being seen as a valuable resource. In most arid and semiarid regions of the world, including the lands of Iran (above 80%) water crisis is considered as one of the main problems on the path of sustainable agriculture [1]. Due to water restrictions and increased water consumption using low quality water resources (wastewater) is considered as a solution to resolve agricultural water requirements which is pointed out as the largest consumption of water recently. In 1996 the total volume of urban and industrial wastewater produced in Iran was 36.3 billion cubic meters (1-BCM) that urban wastewater formed 5.2 units out of all, 5.4 units in the year of 2001 and it is forecasted about 7 BCM for 2011. Availability of good quality water for irrigation is limited worldwide and thus agriculture is likely to be forced to make increasing use of municipal wastewater [2]. In view of recent advances in crop management, irrigation and drainage methods, it becomes feasible to use low quality water for irrigation with minimum adverse impacts on plant growth and productivity [3]. Drip systems result in increased productivity and nutrient saving. However, the system has problems of seasonal labor requirement in spreading and collecting the laterals in addition to its deterioration because of its exposure to above soil surface condition particularly in sunny hot climates. To solve these problems, subsurface drip irrigation is being studied. This system has additional advantages over surface irrigation including placement of both water and nutrients at the center of the root system with water content being relatively high and steady with time [4, 5], and decreased evaporation of water from soil surface resulting in increased water availability to plants [6], and movement of nutrients in larger volume around the emitter in spherical volume, while in the case of surface application the movement is restricted to a semispherical volume below the drip (7). Kalavrouziotis (2010) found that crop yield and water use efficiency (WUE) were slightly higher when applying water through subsurface drip than through surface drip [8]. Martinez et al. (1991) found that marketable and total ear yields of corn for subsurface trickler were higher than for surface tricklers. Total fresh weight, dry matter production and plant height during the growing season were greater for subsurface than for surface content at the