Abstract:

To explore the nitrogen and phosphorus uptake and utilization strategies of barley under different nitrogen fertilizer levels in the Erhai Lake watershed, and to provide a theoretical basis for efficient nutrient utilization and sustainable agriculture in the watershed, a field experiment was conducted in this study. Five N fertilizer treatments were set up in the field experiment, and two local barley varieties, ‘Yundamai 2’ and ‘S4’, were selected to examine the dry matter accumulation, nitrogen and phosphorus utilization and yield formation at the flowering and mature stages. The results showed that dry matter accumulation and yield formation of barley at maturity were improved with increasing nitrogen application, and it was mainly due to the increase of grain number of per unit area, while the change in 1000-grain weight was not significant. Different applications of nitrogen fertilizer had little effect on the P concentration in the organs of barley at anthesis and maturity, while the N concentration in the stems and leaves increased with increasing N application. From flowering to maturity, the accumulation of N and P in stems and leaves decreased significantly, while the accumulation of N and P in spikes increased significantly. The increase of N application could improve dry matter accumulation and yield formation in barley. Although the decrease of N and P accumulation in stems and leaves did not change significantly with the level of N application from flowering to maturity, the N and P accumulation in spikes significantly increased from flowering to maturity.

Key words: barley, nitrogen levels, yield formation, nitrogen and phosphorus uptake, dry matter accumulation, nitrogen and phosphorus utilization efficiency