Characterization of Soil Bacterial Diversity in Relation to Irrigation Water: A Case Study in China

Use of wastewater for irrigation has become indispensable worldwide due to accelerating water scarcity, and it also carries a social dimension of poverty reduction in developing countries. However, the impacts of wastewater irrigation on soil properties are still insufficiently understood, especially with regard to change in soil microbial community characteristics. The present study presents an assessment of soil bacterial communities subjecting to different irrigation waters. We conducted soil sampling in farmlands irrigated with wastewater, river water and groundwater respectively in an arid region of China and performed a metagenomic survey of microbial populations using the prokaryotic 16S ribosomal RAN gene. It sheds new light on possible alteration of soil bacterial diversity due to irrigation water. It also reveals that the relative abundance of nitrifying bacteria is greater in soil irrigated with river water than soil irrigated with wastewater. The opposite is true for denitrifying bacteria. The findings serve as a call for further in-depth study to explore the long-term responses of soil microbial communities to irrigation waters for the sake of environmentally sound watershed management.