Responses of nitrogen metabolism, photosynthetic parameter and growth to nitrogen fertilization in Rumex patientia L. × Rumex tianschanicus Losinsk

Edible grasses (Rumex patientia L. Rumex tianschanicus Losinsk.) are highly prized as a superior food ingredient due to their abundant yields and rich protein content.Nevertheless, this particular crop lacks a symbiotic N fixation system, resulting in an equally significant requirement for N fertilizers.Nitrogen is a highly sought-after mineral ingredient that plays a constant role in the growth and development of plants.This study aimed to investigate the optimal N delivery for hydroponically cultivated leaf-eating grasses.The study included five different N concentration treatments: 45.53 (N1), 91.06 (N2), 136.59 (N3), 182.12 (N4), and 262.65 mg L -1 (N5).These treatments were used to assess the impact of varying N supply levels on the growth indexes, N utilization efficiency, and photosynthetic rate of phloem.The study observed that the growth indexes of leaf-eating grass, such as plant height, diameter, number of tillers, biomass, N buildup, and photosynthetic rate, exhibited a pattern of initially increasing and subsequently declining with higher N levels.Specifically, at a N concentration of 136.59 mg L -1 (N3), the indices reached the highest point with plant height of 23.18 cm, ground diameter of 6.06 mm, tiller number of 9.14, whole plant biomass of 1.10 g, whole plant N accumulation of 49.48 g, and N utilization of 19.92, which were significantly (P < 0 .05)higher compared to other treatment levels.This optimal N level was favorable for promoting plant growth and contributing to the accumulation of proteins and other organic substances.