The study of nitrogen use efficiency and its related traits in winter cereals

Nitrogen is the most important factor limiting the growth and performance of crops, especially cereals. Therefore, with the aim of investigating the nitrogen use efficiency and its components in different cereals under the conditions of control (no use nitrogen) and optimal conditions of nitrogen, a factorial field experiment was conducted base on randomized complete block design with three replications at Gonbad Kavus University in 2017-2018. The experimental treatments included cereals at 7 levels, including bread wheat Koohdasht cultivar, durum wheat Seimareh cultivar, two rowed barley Khoram cultivar, six rowed barley Sahra cultivar, hull less barley Line 17, triticale Javanilo cultivar and oat Canadian cultivar) and the nitrogen factor were evaluated at two control (zero) and optimum levels. The result showed that cereal × nitrogen interaction was not significant on nitrogen utilization efficiency, nitrogen uptake efficiency and nitrogen use efficiency, nitrogen harvest index, nitrogen content and grain protein. But the main effect of nitrogen and cereals on nitrogen uptake efficiency, nitrogen utilization efficiency and grain protein percentage was significant at 1% level. While the nitrogen harvest index was only affected by cereals, Also, nitrogen remobilization was affected by cereals, nitrogen and cereals × nitrogen interaction. Finally, the results of this experiment showed that nitrogen use efficiency increased in all studied cereals under optimal nitrogen conditions. Nitrogen use efficiency consists of two components, nitrogen uptake efficiency and nitrogen utilization efficiency, as a result, the increase in nitrogen use efficiency is mostly due to the improvement in nitrogen uptake efficiency. Also, in all cereals under optimal nitrogen conditions, protein percentage and grain yield increased, in order to the increase in protein percentage was due to increased nitrogen remobilization. On the other hand, hull less barley had a higher nitrogen use efficiency than other cereals.