Effects of Topdressing Nitrogen Fertilizer at Different Growth Stages on Growth Dynamics and Quality of Beer Barley

【Objective】 To study the effects of topdressing nitrogen fertilizer on the economic characteristics and quality of beer barley during different growth periods, and determine the best topdressing time of nitrogen fertilizer for beer barley. 【Method】 Taking the barley varieties introduced and self-fertilized in recent years as test materials and using the split zone design, the effects and changes of topdressing nitrogen fertilizer at different growth stages on the economic characteristics, yield and quality of different varieties were studied. 【Result】 With the delay of the nitrogen topdressing period, the heading and maturity periods were delayed; the application of nitrogen fertilizer at the booting and heading stages significantly increased the number of days of growth; the highest total stem number and effective ear number of topdressing nitrogen fertilizer at the two-leaf and one-heart stage showed the best performance with significant differences; plant height, yield components, and yield had the best effect of topdressing nitrogen fertilizer at the jointing stage, and the differences were significant; protein content was positively correlated with the nitrogen topdressing period. With the backward shift of topdressing nitrogen fertilizer, protein content was higher. 【Conclusion】 Topdressing nitrogen fertilizer at the two-leaf and one-heart stage can significantly improve the economic traits of beer barley; topdressing nitrogen fertilizer at the jointing stage can significantly increase the yield of beer barley and significantly improve its grain quality. Therefore, this study showed that topdressing nitrogen fertilizer at jointing stage could achieve synergistic improvement of yield and quality.