The Relationship Between Corn Yield and Water Consumption (Computational water demand and lack of soil moisture)

Water recourses planning in the arid and semiarid areas which are faced with water restrictions, both in quality and quantity, is very important, yet it is too difficult. Utilizing targeted low irrigation can be one of the approaches to deal with water shortages. According to their regions and physiological conditions, various plants show different reactions to water shortages. This survey in the form of the perfect randomized block program contains 9 different levels of irrigation in 3 repeating times on the SC704 corn cultivars had been applied in 2012 at the Islamic Azad University Golbahar branch farm in Mashhad. samples contain 7 levels of irrigation (11,12,13,14,15,16,17) respectively equivalents to 120%,100%,90%,80%,70%,60%, and 50% of the plant water requirements, and two other levels based on the soil water depletion(SWD)(19 and 18 respective irrigation when 50 and 70 percent of the corps capacity moisture depleted).results indicate that change in the amount of water consumption, directly affects the crop performance. Also, targeted water shortage by optimized and low water consumption, can have more suitable performance on crops production. The highest plant height is related to the sample11 and equals to 209 cm and the least of them is related to the sample 17 and equals to 32.5 tons in per hectare, and it happens when the irrigation of about 50 percent of full water requirement has done. The results indicate that the efficiency of water consumption (seed performance) in samples that irrigation takes place based on the soil humidity is higher than the other samples.