Spatially-resolved, consortial approaches towards a mechanistic understanding of soil nitrogen fate
EMSL Project ID
49480
Abstract
Nitrogen acquisition is a key determinant of plant productivity and the fate of nitrogen, both applied and endogenous, is largely controlled by microbial processes. Furthermore, microbially-induced loss of nitrogen contributes both to lacustrine and riverine eutrophication and emission of N2O, a greenhouse gas 300 times as potent as CO2. Although the environmental variables governing the fate of soil nitrogen are relatively well-understood at the field scale, the mechanisms by which environmental controls alter processes at the cellular scale are much less clear. This mechanistic understanding is critical for multiple BER-relevant applications, including 1) predicting N biogeochemistry, 2) predicting SOM mineralization and N effects on C cycling, and 3) determining control points to improve soil nitrogen retention and improve biofuel crop sustainability. Here we propose to 1) apply methods developed under the FSFA to generate consortial models of soil nitrogen cycling for species-resolved, genome-enabled experimentation, and 2) design a pore-scale microfluidic model to examine the impact of microbial behavior upon nitrogen immobilization. This will entail (1) cultivation of consortia specializing in aspects of soil carbon and nitrogen cycling (nitrification, denitrification, nitrite ammonification, N2 fixation, and oxygenic photosynthesis) from the Panicum virgatum rhizosphere and associated soils, (2) metagenome sequencing of those consortia and (3) reconstruction into species-resolved bins. Concurrently, we propose to develop a microfluidic device capable of simulating wetting/dry-down events, gas exchange, and nitrogen retention by mimicking clay mineral surface chemistries. Once complete, this investment will align with future research directions in both the FSFA and SBR SFA and position PNNL well for increased visibility for BSSD and CESD emphases on soil carbon-nitrogen cycling.
Project Details
Start Date
2016-05-11
End Date
2016-09-30
Status
Closed
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