Adaptability evaluation of several native plants in the desert steppe of Ningxia

The evaluation of the adaptability of native plants is important for the ecological restoration of degraded grasslands. The native plants of the Ningxia desert steppe, Lespedeza potaninii, Astragalus melilotoides, Agropyron mongolicum (wild), A. mongolicum (domestication), and A. mongolicum (new), were evaluated for their adaptability in terms of agronomic traits, photosynthetic characteristics, and feeding value in 16 indicators. The results showed that the growth rate, leaf-stem ratio, and hay yield of L. potaninii were significantly higher than those of the other four plants (P < 0.05), and the overwintering rate reached 100%. The net photosynthetic rate of three gramineous plants was significantly higher than that of two leguminous plants (P < 0.05), and the intercellular CO₂ concentration showed a converse trend. The differences in stomatal conductivity and transpiration rate among the 5 materials were not significant (P > 0.05). The crude protein content of A. melilotoides was significantly higher than the other 4 plants (P < 0.05), and the content of neutral detergent fiber and acid detergent fiber was lower, with a high relative feeding value. The comprehensive evaluation by the gray correlation method revealed that the adaptability of the five native plants showed the trend, A. melilotoides > L. potaninii > A. mongolicum (domestication) > A. mongolicum (wild) > A. mongolicum (new) under an equal-weighted correlation, and A. melilotoides > A. mongolicum (domestication) > L. potaninii > A. mongolicum (wild) > A. mongolicum (new) under a weighted correlation. The study concluded that A. melilotoides and A. mongolicum (domestication) can be preferred in the construction of desert steppe vegetation in Ningxia and similar areas.