Abstract:

Soil acidification coupled with high contents of aluminum loads in red soils in the Southeast of China, posing a great threat to soil fertility and plant growth. The application of soil amendments is an effective way to improve acidified soil, remediate heavy metal pollution, and improve crop productivities. Here our study selected four soil amendments such as coconut, lime, biochar and plant ash, and conducted a 180-day greenhouse pot trial, to explore the effects of soil amendments on soil properties, plant growth and physiology of Hongmeiren, and soil microbial communities. The results showed that the four amendments significantly improved the soil acidification, reduced the aluminum contents, and increased soil carbon and nitrogen contents; the application of soil amendments had no significant effect on the root activity, but increased β-carotenoid contents of leaves of Hongmeiren; structure of soil bacterial community had significantly been changed, especially reducing the relative abundances of Proteobacteria and Pseudomonas; zero model (null model) revealed that the microbial assembly process was a deterministic process rather than stochastic process. These findings indicate that soil amendments could effectively alleviate the acidification of soil, promote plant photosynthesis, increase energy substances, and change the assembly mechanism of soil microbial community.

Key words: soil amendments, soil remediation, Hongmeiren, microbial community, plant physiology, remediation mechanisms