Effects of nitrogen levels on matter accumulation and nitrogen use efficiency of Buchloe dactyloides

To provide a theoretical basis for the management of nitrogen fertilizer of Buchloe dactyloides, two cultivars, ‘Sundancer’ and ‘Texoka’, two cultivars of Buchloe dactyloides, were used as the test materials to explore the effects of different nitrogen levels (N₀: 0 mg·kg⁻¹, N₁: 500 mg·kg⁻¹, N₂: 1500 mg·kg⁻¹, N₃: 2500 mg·kg⁻¹, and N₄: 5000 mg·kg⁻¹) on matter accumulation and nitrogen use efficiency (NUE). The results showed that, compared to the nitrogen deficiency environment, 500 mg·kg⁻¹ was the best nitrogen application. Chlorophyll, reducing sugar, soluble protein, nitrate nitrogen, ammonium nitrogen, total nitrogen, and total carbon levels and biomass were significantly improved (P < 0.05). When nitrogen application exceeded 500 mg·kg ⁻¹, nitrate nitrogen, ammonium nitrogen, total nitrogen, total carbon, and biomass increased slightly, but NUE decreased significantly (P < 0.05). When nitrogen application exceeded 2500 mg·kg ⁻¹, reducing sugar and nitrate nitrogen levels and biomass were significantly reduced (P < 0.05), and growth and matter accumulation were restrained. Buchloe dactyloides has a strong tolerance to a low nitrogen environment, and it may improve its stress resistance through the massive accumulation of starch and soluble sugar. The production capacity and nitrogen use efficiency of ‘Texoka’ were higher than those of ‘Sundancer’.