Conservation tillage enhances the stability of the rhizosphere bacterial community responding to plant growth

Soil microbes play important roles in plant growth and nutrient cycling. Conservation tillage is extensively used in northern China, which alters the soil structure and nutrient conditions, causing changes in the soil microbial community. However, the influence of conservation tillage on rhizosphere bacteria during plant growth, and associations with plant root nutrient efficiency, and plant productivity remains unclear, particularly regarding the effects on the stability of the soil bacterial community that modifies plant growth. Therefore, the aim of this study was to evaluate the contributions of conservation (chisel plow, zero) tillage and conventional (plow) tillage on the soil rhizosphere bacterial community throughout plant growth. The responses and succession of the bacterial community in the rhizosphere of winter wheat crops growing under conservation and conventional tillage practices were determined through high-throughput sequencing of 16S rRNA. The response of plant growth was determined by measuring plant carbon and nitrogen accumulation from the wheat tillering stage to the flowering stage. Here, we show that variations in rhizosphere alpha and beta diversity throughout plant growth had the greatest contributions to distinguishing conventional plow tillage from conservation (chisel plow, zero) tillage. Additionally, zero tillage (dissimilarity: 11.3%) had less of an effect on the relative abundances of Proteobacteria (Alpha-, Beta-, Gamma-) and Bacteroidetes in the rhizosphere in response to plant growth as compared with plow tillage (dissimilarity: 21.7%). This is the first in-depth study of the effects of conservation and conventional tillage on the stability of rhizosphere bacterial community in response to plant growth. Furthermore, our study indicates that conservation tillage can modify the soil conditions and preserve rhizosphere bacterial memberships. The consequent enhanced stability of the plant growth-promoting rhizobacteria population can help to establish a profitable agroecosystem to in turn enhance soil nutrient conditions and improve plant production sustainably.