Effect of deficit irrigation with treated wastewater on corn yield

The water crisis is one of the fundamental issues in arid and semi arid regions like Iran. Therefore, the use of unconventional water resources, where good quality water is not available, is increasing. One of these resources is treated wastewater which in addition to the water supply can also provide some of plants nutritional requirements. The statistical design used for this study was a factorial design experiment based on a completely randomized factorial design having two types of irrigation water with four levels of plant water stress: absence of plant water stress (control), low stressed (80%), moderately stressed (60%), and severely stressed (40%) with three replications. Analysis of variance showed that irrigation with treated wastewater and normal water affects shoot wet and dry weights of crop, ear weight, root wet and dry weights and plant height and diameter. In other words, plant growth depends totally on the type of water for irrigation and possibly on presence of nutrients and organic matter in the wastewater. Results showed that irrigation with treated wastewater increased wet and dry weights of shoots and roots of corn. With exerting more water stress, wet and dry weights of shoot and root were reduced, however, this reduction in treated wastewater was lower when compared to normal water. Shoot wet and dry weights related to treated wastewater without stress (100%) had the highest values 874/3 and 306 respectively which show an increase of about 45.5 and 59.2%, respectively when compared to normal water under severely stressed condition (40%). Therefore, deficit irrigation with treated wastewater significantly increased the yield of corn rather than deficit irrigation with normal water.The use of treated sewage along with a permanent water quality monitoring network is recommended.