Microbial community structure, function and mobile genetic elements in the rhizosphere of Avena sativa L. under glyphosate desiccation and mechanical suppression

Cover crops have gained a growing popularity in sustainable agricultural practices based on the multiple benefits for soil health. Among them Avena sativa L. represents a clear example of a non-resistant crop treated with glyphosate based herbicides (GBHs) as a desiccation agent during the suppression step, before planting the main crop (e.g. soybean and maize). Most studies of glyphosate impact on soil microbial communities have focused on bulk soil or in the rhizosphere of glyphosate resistant crops. Instead, a considerable lower number of studies have addressed the comparison of microbial communities from the rhizosphere of sensitive crops (GS) under GBH dependent and independent managements. Considering the growing trend of cover crops in sustainable agriculture, a comparison of the effects of mechanical suppression and glyphosate desiccation on microbial communities is required to identify which parameters could differ in the long term under sustained use of each suppression method. Different rhizhospheric microbial communities assembled in the remaining root material, after mowing or glyphosate desiccation of the CC, could result in differential effects on the following crop. The objective of this project is the assessment of the impact of GBHs on rhizospheric microbial communities of A. sativa L. relative to the mechanical suppression.