عنوان مقاله [English]
Today in agriculture, the effective use of limited soil and water resources and cultivation of new crops, resistant to environmental challenges, such as quinoa have been considered. In order to investigate the interaction effect of different levels of irrigation water and nitrogen fertilizer on yield and yield components of quinoa (cv. Titicaca), a field experiment was conducted on March 2017 during four months at Shiraz University in the Bajgah area of Fars province. A factorial experiment was conducted in a randomized complete block design with twelve treatments and three replications. Nitrogen (N) fertilizer treatments were four levels of zero, 125, 250, 375 kg N ha-1 and the irrigation water strategies were three levels of full irrigation (FI), 75% and 50% full irrigation (0.75FI and 0.5FI. After tillage operations, quinoa seeds were planted with a density of 20 plants per square meter. Irrigation treatments were applied after plant establishment with basin irrigation method. Nitrogen fertilizer was given to the field at two stages of vegetation and grain filling.). Irrigation amount reduction of 25% had no significant effect on seed yield at zero, 125 to 250 kg N ha-1 nitrogen fertilizer application levels Increasing nitrogen fertilizer application levels from 250 to 375 kg N ha-1 under deficit irrigation (0.75FI and 0.5FI) did not cause a significant difference in grain yield and the total dry matter of quinoa. Generally, the recommended irrigation regime and optimum nitrogen fertilizer application rate in the study area (Bajgah) for quinoa, based on the yield, total dry matter, harvest index, 1000-seed weight, water productivity are 0.75FI and 250 kg N ha-1 nitrogen fertilizer. Moreover, the chlorophyll index (SPAD) threshold value was 55 for the optimum nitrogen fertilizer application rate.