Implications of continuous and rotational cropping practices on soil bacterial communities in pineapple cultivation.

Bacterial communities in cultivated soils contribute to soil organic matter dynamics and nutrient cycling. Despite numerous reports on the influence of cropping practices on soil microbial community structure, the knowledge of bacterial response to pineapple (Ananas comosus (L.) Merr) cropping systems is very limited. Here, rhizosphere and inter-row soil bacterial community composition in continuous and rotational pineapple (variety: Comte de Paris) cropping at two sites (Leizhou and Xuwen in Guangdong Province, China) during summer (May 2017) and winter (December 2017) were assessed via Illumina high-throughput sequencing of PCR-amplified 16S rRNA genes. Our results showed that: (1) leaf nitrogen, chlorophyll contents and yield of pineapple under rotational cropping were significantly higher than continuous cropping; (2) significant differences of soil bacterial community composition were observed between continuous cropping and rotational cropping; (3) Ten representative differentially distributed genera: Acidobacteria_unclassified , Castellaniella , Holophagae_ unclassified , Frigoribacterium , Crenotalea , Nitrosospira , Clostridium _ sensu_stricto_8 , Pusillimonas , Acidiphilium and Mizugakiibacter were identified, and divided into three functional types: acidophilic, denitrifying bacteria, and ammonia-oxidizing bacteria; and (4) the relative abundances of these 10 differentially distributed genera were significantly or highly significantly correlated with leaf nitrogen, chlorophyll contents and yield of pineapple. Due to these results, we deduce that rotational cropping practice may increases pineapple yield by affecting bacterial community structure. • Pineapple yield under rotational cropping was higher than under continuous cropping. • Bacterial community differed greatly between rotation and continuous cropping. • Ten differentially bacteria genera in response to rotation and continuous cropping. • The ten bacteria genera were significantly correlated with the pineapple yield. [ABSTRACT FROM AUTHOR]