Abstract:

This study investigated the effects of sowing date and nitrogen application rate on grain yield and quality of the barley variety ‘Yundamai 10’, aiming to provide a scientific basis for its large-scale production and application. A two-factor randomized block design was adopted, examining three sowing dates (D1: October 21^st; D2: November 1^st; D3: November 11^th) and two nitrogen levels (N1: 150 kg/hm² urea; N2: 225 kg/hm² urea) on grain yield, key agronomic traits, protein, starch, fat content and so on. The results showed that sowing date had highly significant or significant effects on all measured traits. With delayed sowing, grain yield reduced significantly. Compared with D2 and D3, D1 increased grain yield by 87.93% and 76.79% respectively, while protein content increased significantly under later sowing. Nitrogen application significantly influenced grain yield but not yield components, agronomic traits or quality parameters. The gain yield under N1 was significantly lower than that under N2, indicating that excessive nitrogen application reduced yield instead of increasing it. Although the protein content under N1 was lower than that under N2, the difference was not significant. Delayed sowing significantly decreased grain yield but increased protein content; excessive nitrogen application significantly reduced yield while marginally increasing protein content, suggesting a trade-off between high yield and protein content improvement. However, the increase in protein content was limited by the genetic characteristics of the variety. Therefore, sacrificing yield for quality improvement was not recommended for this variety. Early sowing combined with a urea application rate of 150 kg/hm² was recommended to achieve high yields.

Key words: forage barley, sowing date, nitrogen application rate, grain yield, quality