Plant growth, salt removal capacity, and forage nutritive value of the annual euhalophyte Suaeda salsa irrigated with saline water

Abstract

Sustainable agricultural development in semiarid and arid regions is severely restricted by soil and water salinization. Cultivation of the representative halophyte Suaeda salsa, which can be irrigated with saline water and cultivated on saline soils, is considered to be a potential solution to the issues of freshwater scarcity, soil salinization, and fodder shortage. However, the salt removal capacity and differences in the forage nutritive value of S. salsa under different saline water treatments remain unknown. Using the methods of field trials and randomized blocks design, we quantified salt accumulation in the aboveground biomass, and the biochemical and nutritive value of field-cultivated S. salsa in arid northwestern China under irrigation with water of different salinities [i.e., freshwater or water containing10, 20, 30, or 40 g/L NaCl). The fresh and dry weights of S. salsa increased, then decreased, with increase in salinity. The salt content of the plant’s aboveground biomass increased to a constant range and, thus, the salt extraction of S. salsa was relatively stable under different salinities of irrigation water. Under the experimental conditions, the crude protein content significantly increased to 9.45% dry weight (DW) and then decreased to 6.85% DW, with an increase in salinity (p < 0.05). The neutral detergent fiber (42.93%–50.00% DW) and acid detergent fiber (34.76%–39.70% DW) contents were suitable for forage. The contents of trace elements, such as copper and zinc, were significantly increased after irrigation with saline water (p < 0.05). The forage of S. salsa is of high nutritive value for livestock, and contains low concentrations of anti-nutrients. Therefore, S. salsa can be considered for cultivation in saline soils irrigated with saline water. In addition, it provides a viable additional source of fodder in arid regions, where the availability of freshwater and non-saline arable land is limited.

Exogenous Sodium and Calcium Alleviate Drought Stress by Promoting the Succulence of Suaeda salsa

“…Euhalophytes are plants that can tolerate high levels of salinity and often display tissue succulence as a visible trait [ 12 ]. Research has found that the succulence of S. salsa leaves increases with increasing salt concentrations [ 24 ] and that there is a linear correlation between the succulence of euhalophytes ( Salicornia europaea , S. salsa ) and the dry mass of the shoot [ 32 ]. This suggests that it is possible to use the degree of tissue succulence as an indication of plant growth under salt stress.…”

“…Field studies showed that the aboveground biomass of S. salsa had a “curvilinear” growth trend as the salt dosage increased, with the highest biomass at 20 g·L −1 . In addition, the succulence of S. salsa leaves increased significantly with increasing salt dosage [ 24 ]. Thus, our results suggest that the degree of tissue succulence does not accurately reflect the growth state of halophytes under salt stress.…”

“…Euhalophytes not only thrived in saline soil but also exhibited a noteworthy increase in their biomass when exposed to optimal salt content. Furthermore, the succulence of euhalophytes leaves ( Suaeda salsa ) has been observed to significantly increase with an increase in irrigation water salinity [ 21 , 22 , 23 , 24 ], which is linked to increases in cell dimensions, a reduction in surface area per tissue volume, and a significant amount of water content per unit of surface area [ 25 ]. This allows them to dilute toxic ion content in their cells, enabling them to withstand large quantities of salt [ 26 ].…”

Effects of water–nitrogen coupling on water and salt environment and root distribution in Suaeda salsa

“…The salt absorption capacity of S. salsa was determined usingthe following Formula (5) ( Wang et al., 2022 ):…”

“…Harvesting these parts can help improve the quality of saline–alkali land ( Liang and Shi, 2021 ). Moreover, S. salsa can be used as livestock feed ( Wang et al., 2022 ). Therefore, the utilization of S. salsa as feed can drive the large-scale development and use of saline–alkali lands ( Zhang et al., 2005 , 2018 ).…”