Location: Soil Management and Sugarbeet ResearchTitle: The effects of agricultural crop residue placement on microbial community and carbon dynamics in an irrigated, no-till corn system
|OLESZAK, HANNA - Colorado State University|
|COTRUFO, FRANCESCA - Colorado State University|
|LEICHTY, SARAH - Colorado State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2020
Publication Date: 11/9/2020
Citation: Oleszak, H., Cotrufo, F., Leichty, S., Stewart, C.E. 2020. The effects of agricultural crop residue placement on microbial community and carbon dynamics in an irrigated, no-till corn system. Meeting Abstract.
Technical Abstract: As microorganisms metabolize soil organic matter, they either assimilate carbon as biomass or respire carbon as CO2, thus resulting in the net stabilization or loss of carbon, respectively. As incentives for soil carbon sequestration and soil health are being developed, it is critical to understand how microbial communities and their processes are affected by various agricultural management practices. We conducted a study tracking 13C labeled residue carbon in either surface applied (SA) or incorporated (INC) residue treatments in an irrigated, continuous no-till cornfield to understand the impacts of residue management on soil carbon stabilization. After two years, the SA treatments resulted in greater residue CO2 loss than INC. To determine how microbial biomass, community structure, and proximity to residue relates to carbon flow, we extracted phospholipid fatty acids (PLFA’s) throughout the soil profile of our treatments from the first 2.5 years of the study. The organic material used in our treatments was labeled with 13C, thus we analyzed the 13C content of PLFA extractions in order to track what microbial members are actively decomposing the labeled organic matter over time and at depth. We expect INC to have greater soil microbial biomass and aggregation than SA. Ultimately, we predict that overall carbon sequestration will be greatly determined by the soil microbial community’s interaction with soil structure. We hope to understand the effects of residue management on microbial community structure and activity, and how they link to the carbon dynamics of our system.