Changes in Microbial Diversity, Soil Function, and Plant Biomass of Cotton Rhizosphere Soil Under the Influence of Chlorpyrifos.

Chlorpyrifos (CPF), a common organophosphorus pesticide, is extensively used in agricultural practices. However, we lack sound evidence for the linkage between soil microbial diversity, soil function, and plant biomass under the influence of CPF, which prevents us from assessing the actual impact of CPF on agricultural production. In this study, we used high-throughput sequencing to test the effects of CPF on soil microbial diversity, soil function, and cotton biomass in indoor pot experiments. The use of CPF leads to a significant reduction in cotton biomass until the concentration of CPF used reaches 15 mg kg-1, and the cotton biomass is no longer significantly reduced. Compared with the original soil, the alpha-diversity of bacteria, which was significantly linearly related to cotton biomass, was significantly decreased when the soil was treated with 15 mg kg-1 CPF. Affected by CPF, the overall soil microbial composition has changed significantly. Acidobacteria, Nitrospirae, Planctomycetes, and Actinobacteria were significantly regulated after CPF treatment. Correspondingly, key soil functions, including nitrogen metabolism and iron (III) transporter, have been significantly down-regulated. The reduction of nitrogen and Fe3+ should deprive the cotton of essential nutrients during the short crop cycle and thus affect cotton biomass. Our study provides experimental evidence that CPF affects cotton rhizosphere soil microbial diversity, the relative content of key bacterial genera, and soil function, which shows that it has an important impact on plant biomass, and provides a reference for studying the actual impact of CPF on the environment and agricultural production.