Effects of Nitrogen Application Rate on Nutrient Utilization Efficiency of Vicia faba

In this study, 3 nitrogen application levels were set in pot experiment, and no nitrogen fertilizer was used as control(CK). Dry matter accumulation, root length were detected and nutrient utilization efficiency were measured at different growth stages. The results showed that the dry weight of Vicia faba at harvest stage increased by 180%–480% compared with that at flowering stage and pod stage, respectively. Compared with T₁, the root length of T₂ and T₃ were increased by 30.64% and 24.19% at flowering and were increased by 21.32%, 27.88% at pod stage, no significant difference between T₂ and T₃. At the harvest stage of V. faba, compared with CK, the nitrogen application rate of T₁, T₂ and T₃ were increased by 33.01%–74.85%, respectively; however, there was no significant difference between T₁ and T₂. Compared with seedling stage, nutrient absorption efficiency of V. faba at harvest stage was reduced by 48.61%–63.54% at 3 nitrogen levels, respectively. In the same growth period, compared with the control group, N use efficiency of T₃ increased by 4.76%–20.74%, respectively; however, there was no significant difference between CK and T₁, T₂. With the increase of nitrogen application rate, N use efficiency was increased, and there was no significant difference in harvest index of V. faba. In conclusion, nitrogen application rate affected the growth and nutrient utilization of V. faba, but did not affect the harvest index, and excessive nitrogen application did not promote the nutrient absorption and utilization of V. faba.