Liangliang Guo

Four typical halophytic communities found in saline-sodic soil, including Phragmites australis, Suaeda glauca, Leymus chinensis, and Puccinellia parl, were investigated in this study. A comparison was made among the electrical conductivity (EC) value, pH value, soil organic carbon (SOC), and soil enzyme activity across various soil depths. The findings of this study indicate that the EC and pH levels of the soil at the 0–40 cm depth vary among the four communities, with Suaeda glauca having the highest values, followed by Puccinellia parl, Phragmites australis, and Leymus chinensis. The highest value of SOC among the four communities was observed in the Leymus chinensis community (0.85–0.94 g/kg), followed by the Phragmites australis community (0.50–0.77 g/kg), and the lowest levels were observed in the Puccinellia parl community (0.37–0.78 g/kg). As the soil depth increases, there is a decline in the amount of SOC. With an increase in soil depth, the content of SOC in the soil decreased, and the content of total nitrogen (TN) and the activity of six enzymes in the soil of each community increased. Furthermore, at the soil layer of 0–20 cm, the TN content in the soils was negatively correlated with pH and EC (p < 0.01), and so was the total phosphorus (TP). Additionally, the TP content is considerably positively connected with alkaline phosphatase (ALP) activity, whereas the TN content is significantly positively correlated with Soil Urease (S-UE) activity. Within the soil depth of 20–40 cm, the levels of TN, TP, and SOC exhibit a negative association with pH and EC. However, this link is weaker compared to that observed in the surface soil. A strong inverse correlation (p < 0.05) exists between the TP concentration and the ALP activity. The objective of this study was to investigate the use of halophytes in various saline-sodic soils for diverse avenues of restoration, and to establish a database on the role and efficacy of plant roots in enhancing saline-sodic soil.

Organic improvement measures play a crucial role in the reclamation of saline‐sodic soil. However, there is still a limited understanding regarding the relationships between soil microbes and soil properties and crop yield in response to the application of these organic materials to saline‐sodic soils. In a field trial, the following treatments were carried out: no modifier input (CK) and compound lignite organic modifier 30 t/ha (LOM) with 2 years of rice cultivation, no modifier input (RF) with 5 years of rice cultivation, and the full amount of straw was returned to the field with rice‐duck farming (SW). Compared with RF and CK, the SOM content in the 0–20 cm soil layer of SW and LOM was significantly increased by 4.600 and 5.020 g kg⁻¹, respectively, while the total alkalinity and pH were significantly decreased. In the 20–40 cm soil layer, the LOM treatment resulted in decreased pH and total alkalinity compared with other treatments. Overall, changes in soil microbial structure changes were significantly associated with SOM and pH levels. In the 0–20 cm soil layer, the LOM treatment significantly increased the relative abundance of Proteobacteria, while SW treatment significantly increased the relative abundance of Bacteroidetes and Firmicutes compared with CK. Moreover，the relative abundances of Longobacteriaceae of Bacteroidetes, Hydrogenaceae, and Xanthomonas of Proteobacteria were positively correlated with crop yield. The yields of SW and LOM were 6985.587 and 7879.910 kg ha⁻¹, respectively. These results demonstrate that implementing comprehensive organic improvement measures can enhance the properties of saline‐sodic soil and increase crop yield, with lignite composite organic amendments may be more suitable for sustainable agricultural development.