1a. Objectives (from AD-416):
Taking advantage of the long term Farming Systems Project (FSP) maintained at BARC for 16 years, we will examine the effects of repeated application of glyphosate or no application of glyphosate on the soil microbial community. To achieve this we will be comparing a number of contrasting small grain production systems specifically comparing conventional till and no-till plots with organically managed plots.Perform system level comparisons of the microbial community in the rhizosphere of Round-up ready corn and soybean varieties with their progenitor isoline and utilize next generation high-throughput sequencing to ensure that we obtain enough sampling coverage to evaluate if history, isoline, or within season application of glyphosate impacts the structure of the soil microbial community in the rhizosphere of corn and soybean crops.
1b. Approach (from AD-416):
ARS will conduct field experiments in its long-term FSP to assess the impact of glyphosate application on general indicators of plant health and subsequent impact on the soil microbial community. The Cooperator and ARS will conduct experiments to quantify the changes in microbial community structure in the rhizosphere of glyphosate resistant and sensitive crop plants in the typical small grain rotations in place at the FSP. The Cooperator will perform all of the necessary bioinformatics computations related to the project.
3. Progress Report:
Research to evaluate the impacts of glyphosate and Roundup Ready soybean on plant health and soil microbial communities has been initiated at three ARS locations in Maryland, Mississippi, and Illinois. In Beltsville, MD, microplots of Roundup Ready and non-Roundup Ready isolines of soybean and corn have been planted within larger plots at the long-term Farming Systems Project. Plant root samples have been collected and will be analyzed for plant pathogens. Plant shoots will be evaluated for residual glyphosate and its breakdown products. Soil samples have been collected and will be analyzed for rhizobial and bulk soil microbial community structure. The indirect effects of glyphosate application on plant pathogen load will be accessed.