Investigating the effect of Regulated Deficit irrigation and Partial Root Dring on some physical and qualitative properties of rice grains and Nitrogen Absorption in furrow cultivation

Due to drought crisis in recent years, the use of alternative cropping methods that saves water without any decrease in yield is increasing. Regulated deficit irrigation is a method of irrigation in which, by supplying part of the maximum crop requirement at specified times, water management is addressed and therefore the root zone is in a dry area most of the time. Using this method will partially stop the growth of the plant and usually decrease yield (Jovanovic et al., 2010). Root Partial Drying (PRD) is a modified form of the deficit, which includes watering one section of the root zone in each irrigation and dry up another side, so the moisture of this section before next irrigation largely come down (Ahmadi et al., 2010). In the root drying method, the roots of the plant simultaneously with soil drying with the production of Abscisic Acid, prevent leaf expansion and reduce stomatal conductance. Simultaneously with this process, the root in the wet part with adequate water uptake puts the plant in proper moisture (Yousri Ibrahim Atta, 2008). Abscisic acid is a plant hormone whose production is increased by root in dry soils and transported by water flow into the stem. (liu et al., 2008). On the other hand, The quality of production is as important in all crops and especially in rice production in Iran. (Salehifar  et al., 2009) In order to evaluate some of the physical and qualitative properties of rice grain and the amount of nitrogen uptake in rice (Hashemi variety) under different irrigation levels and comparing it with continuous waterlogging, an experiment was conducted during two years of cultivation of 2015 and 2016.