Priming Effects of Cover Cropping on Bacterial Community in a Tea Plantation

The acidic nature of red soil commonly found in tea plantations provides unique niches for bacterial growth. These bacteria as well as soil properties are dynamic and vary with agricultural management practices. However, less is known about the influence of manipulation such as cover cropping on bacterial communities in tea plantations. In this study a field trial was conducted to address the short-term effects of soybean intercropping on a bacterial community. Diversity, metabolic potential and structure of the bacterial community were determined through community level physiological profiling and amplicon sequencing approaches. Cover cropping was observed to increase soil EC, available P, K, and microelements Fe, Mn, Cu, and Zn after three months of cultivation. Bacterial functional diversity and metabolic potential toward six carbon source categories also increased in response to cover cropping. Distinct bacterial communities among treatments were revealed, and the most effective biomarkers, such as Acidobacteriaceae, Burkholderiaceae, Rhodanobacteraceae, and Sphingomonadaceae, were identified in cover cropping. Members belonging to these families are considered as organic matter decomposers and/or plant growth promoting bacteria. We provided the first evidence that cover cropping boosted both copiotrophs (Proteobacteria) and oligotrophs (Acidobacteria), with potentially increased functional stability, facilitated nutrient cycling, and prospective benefits to plants in the tea plantation.

Automated summary

This study conducted a field trial in tea plantations to investigate the short-term effects of soybean intercropping on the bacterial community. Results showed that intercropping increased soil EC, available P, K, Fe, Mn, Cu, and Zn, and promoted bacterial functional diversity and metabolic potential. Intercropping also revealed distinct bacterial communities and identified effective biomarkers related to organic matter decomposition and plant growth promotion. This study suggests that intercropping can enhance the growth of both copiotrophs and oligotrophs, potentially improving functional stability and nutrient cycling for plants in tea plantations.