Abstract: In order to investigate the optimum amount and frequency of nitrogen application for buffalograss (Buchloe dactyloides (Nutt.) Engelm.) seed yield production,in this experiment we conducted a randomised block-group design,with nitrogen application amount and frequency as the experimental factors,the nitrogen application amount had six levels (60,90,120,150,180 and 210 kg·hm^-2),and the N application frequencies were set once and twice,and no fertiliser was used as the control. The field experiment was carried out in Zhuozhou,Hebei province,China in 2023. The results showed that the difference of buffalograss plant height,number of reproductive branches,seed yield and nitrogen agronomic efficiency (Nitrogen agronomic efficiency,NAE) increased and then decreased with the increase of nitrogen application. Twice applications significantly increased (P <0.05) seed yield and NAE in compared with that of once application. The increases was 2% to 65% and 11% to 159%,respectively. According to the regression model analysis of nitrogen application amount and frequency with buffalograss and NAE,the total nitrogen application amount of 165.50 kg·hm^-2 led the highest seed yield by dividing into two applications during two growth stages. This study provided a support for fertilizer management of buffalograss seed production in Hebei province.

Key words: Buffalograss, Nitrogen application amount, Nitrogen application frequency, Seed yield, Nitrogen utilization efficiency

摘要： 为探究野牛草(Buchloe dactyloides (Nutt.) Engelm.)种子产量生产的最佳施氮量和施氮频次，本研究于2023年在河北涿州开展田间试验，采用随机区组设计，以不施肥为对照，以施氮量和施氮次数为试验因素，其中施氮量设置6个水平(60,90,120,150,180,210 kg·hm^-2)，施氮频次设置1次和2次。结果表明：随施氮量的增加，株高差值、生殖枝数、种子产量和氮肥农学利用率(Nitrogen Agronomic Efficiency，NAE)均呈先增后减的趋势；相同施氮量条件下，分2次施肥比1次施肥显著提高了(P<0.05)种子产量与NAE，其增幅分别为2%~65%和11%~159%。根据施氮量、施氮频次与野牛草和NAE的回归模型分析，将总施氮量为165.50 kg·hm^-2分两次施入时，能够获得最佳种子产量。本研究为河北地区野牛草的高产制种及肥料的高效管理提供参考依据。

关键词: 野牛草, 施氮量, 施氮频次, 种子产量, 氮肥利用效率