Title: Quantification and fragment analysis of soil and cotton root-associated fungal and bacterial populations under different tillage managements Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 18, 2014
Publication Date: N/A
Technical Abstract: Background: Conservation tillage is a common management practice utilized in the hopes of reducing soil erosion and increasing soil carbon. Evidence suggests that conservation tillage may lead to habitat improvement for soil microorganisms, in particular rhizospheric bacteria and arbuscular mycorrhizal fungi (AMF) communities. In turn, these communities may confer drought resistance for plants, and decrease fertilizer inputs. To gain a better understanding of how soil management practices influence plant-soil-microbial interactions, we conducted an experiment utilizing plots established in 1978 to compare the long-term effects of conventional and conservation tillage. Plots are currently under a corn-cotton rotation allowing us to examine the effects of both crop type and soil management on microbial communities. We are currently on the third year of this particular study. Methods: AMF were quantified using quantitative Real Time polymerase chain reaction (qPCR) and an AMF specific primer set. Bacterial communities were “fingerprinted” and analyzed using terminal restriction fragment length polymorphism (T-RFLP). We also utilized second-generation deoxyribonucleic acid (DNA) sequencing methods to identify the fungal populations in the system. Results: Year one of the study revealed distinct soil microbial communities between both crop type and soil management practice. For conventional and conservation tillage, these differences were significant both before and after planting. Stability of the bacterial cotton rhizopsheric community structure was more quickly established in conventional tillage, as compared to conservation tillage. The second year of the study has masked some of the differences saw between crop type and soil management. We are currently in the process of elucidating responsible environmental factors to account for the disparity between the yearly results. Conclusion: By correlating microbial communities and colonization rates with plant nutrients and soil properties, findings from this study will further our understanding of how soil management practices impact plant-microbe relations and plant productivity. Ultimately, this research can aid in the development of best management practices that reduce fertilizer and water input.