Impacts of sulfur application on microbial communities and functional attributes in rubber plantation soil

Elemental sulfur is widely used in fungicide applications to control crop diseases in agricultural systems, but its effects on soil microbial communities are largely unknown. In China, significant amounts of elemental sulfur are sprayed annually on rubber plantations to support crop performance. To investigate the effects of sulfur spraying on microbial diversity, composition, interactions, and functionalities in rubber plantation soil, soil samples from rubber plantations in Yunnan, South China, were collected, and bacterial and fungal communities were analyzed through high-throughput sequencing. Results showed that sulfur application did not alter the alpha diversity but the beta diversity of the soil bacterial community. Notably, sulfur disturbed the relative abundances of Chloroflexi and Planctomycetes. Certain bacteria (e.g., Bacillus and Sinomonas) thrived under sulfur treatment, influencing nutrient cycling. The ecological network analysis revealed enhanced bacterial and fungal interconnections. Sulfur application had a limited impact on microbial phenotypes and community functions, yet it inhibited sulfur compound respiration. These findings indicate that sulfur spraying can shift microbial community composition and influence nutrient cycling by favoring specific microbial groups. Despite its limited impact on microbial phenotypes, sulfur affects key metabolic processes, such as sulfur respiration, which are vital for soil health and microbial activity. The results highlight the need for sustainable sulfur management to optimize nutrient cycling and soil health on rubber plantations.