The importance of soil conditioners controlling bacterial biodiversity of vegetable fields under continuous cropping

Abstract

A soil-borne fungal parasite (Plasmodiophora brassicae Woron) has regularly caused 50-60% reductions in the seasonal yield of a 35 years old cabbage plantation under garlic revaccination in China. We investigated the impact of soil conditioners on soil chemical properties and bacterial communities in order to recommend actions to address increasing frequencies of root-resistant cabbage infections. The results showed urease and polyphenol oxidase activities increased by 10.4-15.8% in the topsoil after two-years of quicklime and organic fertilizer application. High throughput sequencing data showed significant increases in the relative abundance of bacteria with potential for biocontrol (Xanthomonadales, Pseudomonas, and Bacillus) under lime and bioorganic fertilizer. Also, according to a forward-selection CANOCO analysis, in this case the two most important variables contributing to the variation in bacterial communities’ composition were soil organic matter and total nitrogen.