Rhizobacterial communities and crop development in response to long-term tillage practices in maize and soybean fields on the Loess Plateau of China

Abstract

Abstract Conservation tillage, that is, reduced or zero tillage, can change the soil ecological environment and rhizosphere bacterial communities. Here, we investigated temporal variations in rhizosphere bacterial communities during crop development and their relationships with crop growth characteristics under three tillage practices (Plow tillage (PT), chisel plough tillage (CPT), and zero tillage (ZT)) in maize and soybean fields on the Loess Plateau of China. Conservation tillage (CPT and ZT) practices significantly increased the contents of soil moisture (3.62–13.13%), soil organic carbon (29.19–39.67%), and nitrogen (38.69–60.23%) and decreased soil pH (1.15–3.76%). The overall responses of rhizosphere bacterial community composition to tillage practice and phenological period were taxonomically consistent across maize and soybean fields, and changes were predominantly observed in the relative abundances of dominant bacterial phyla. Co-occurrence network analysis indicated that the average connectivity degree among 16S operational taxonomic units was higher under PT (38.92% and 73.60%) practice than under CPT and ZT practices. CPT practice tended to increase the total biomass and nitrogen accumulation of maize and soybean compared with PT practice, whereas ZT practice significantly (P