Conservation Strip Tillage Leads to Permanent Alterations in the Rhizosphere Microbiota of Brassica napus Crops.. Winter Oilseed rape rhizosphere microbiome

Microbes play vital roles in many soil ecosystem functions and services, many of which are crucial for agricultural productivity. Among different agricultural management practices, soil tillage methods can result in significant changes in a soil’s physical, chemical and biological properties, including the soil microbiome. In addition, crop type and the plant developmental stages are important drivers of rhizosphere bacterial microbiota structure and composition. Here, we have used high-throughput 16S amplicon sequencing to explore the Brassica napus (winter oilseed rape) rhizosphere bacterial structure, diversity and composition in two contrasting tillage practices; conventional-plough based tillage and conservation strip tillage over three different plant growth stages (vegetative, flowering and harvesting stage). Our finding show that tillage and growth stages were significant determinants of microbial community structure and composition but the effect of tillage became stronger at plant maturity. The combined effect of conservation strip tillage and harvesting stage had a significant impact on the rhizosphere microbiota selection. Our results showed that under conventional tillage system there was no significant impact on rhizosphere microbiota over the growth stages of oilseed rape. However, the rhizosphere bacterial community of oilseed rape under conservation strip tillage was significantly different. Our data suggests that different tillage regimes created distinct ecological niches that selected different microbiota with potential consequences for the ecosystem services provided to the plants and the soil environment.