The Effect of Nitrogen Fertilizer on Some Growth Traits and Yield of Quinoa (Chenopodium quinoa Willd) Irrigated with Sugar-cane Fields Drainage Water

In order to study the effect of nitrogen and irrigation application with sugar-cane effluent on yield, yield components, grain nitrogen and nitrogen use efficiency of Quinoa (Gizzavan), a field trial was conducted as split plot design in 2018-19. In this experiment, four levels of nitrogen fertilizer (0, 75, 150, 225 kg ha-1) using urea fertilizer as a main factor and three levels of irrigation water including control (Karun river water with 2.5 dS m-1 salinity), alternative irrigation with river water and sugar-cane effluent (with salinity of about 5 dS m-1), and irrigation with sugar-cane effluent (with 7.5 dS m-1salinity) as sub-factor were performed in three replications. The maximum leaf area index, grain yield, index harvesting and nitrogen content of quinoa seed were obtained with application of 150 kg N ha-1. The maximum 1000-grain weight (2.77 g) was observed in treatment irrigated with Karun river water. Application of 150 kg N ha-1 and alternative irrigation improved leaf area index (51%), grain yield (79%), harvest index (60%), grain nitrogen content (61%) and finally increased nitrogen use efficiency. In irrigation treatment using sugarcane effluent, increasing nitrogen levell in the soil, not only did not mitigate the adverse effects of salinity, but also decreased the nitrogen content of the seed. Generally, the results of this study indicated that using adequate nitrogen fertilizer can mitigate the detrimental effects of salinity on plant growth and yield.