Vermicompost Application Enhances Halophyte Suaeda salsa Performance and Improves Coastal Saline Soil Quality

Vermicompost is a commonly used organic fertilizer that can effectively improve the fertility and structure of saline soil. However, the effect of vermicompost on the growth of halophytes in coastal saline soil, especially under flooding conditions, is obscure. We conducted two greenhouse experiments in which seeds and seedlings, respectively, of the Suaeda salsa were subjected to no flooding, episodic flooding, or continuous flooding, crossed with or without vermicompost addition, in a factorial design. Continuous flooding decreased seed germination and seedling biomass of S. salsa. Under no flooding or episodic flooding, vermicompost addition significantly increased seed germination and seedling growth in S. salsa, but vermicompost addition had no significant effects under continuous flooding. Vermicompost addition increased the stability of soil aggregates and decreased soil electrical conductivity, thereby improving the soil quality. Our results suggest that vermicompost addition could be an effective strategy for enhancing the population growth of S. salsa in saline soil and benefit the restoration of the S. salsa community in the Yellow River Delta, China.