Additional Funding Sources
The project described was supported by Institutional Development Awards (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under Grant Nos. P20GM103408 and P20GM109095, and National Science Foundation S-STEM Gateway Scholarships in Biological Sciences under Grant Award No. DUE-1644233. We also acknowledge support from the Biomolecular Research Center at Boise State with funding from the National Science Foundation, Grant Nos. 0619793 and 0923535, the M.J. Murdock Charitable Trust, and the Idaho State Board of Education.
Presentation Date
7-2021
Abstract
Big Bluestem and Switchgrass are promising candidates for cellulosic bioenergy production. Increased removal of atmospheric CO2 is a key aspect of bioenergy production to ensure that more CO2 is removed than produced, via biofuel conversion. This makes it an ecologically sustainable process. Plant roots can contribute to atmospheric CO2 removal through the process of photosynthesis, transferring C from atmosphere to soil, where it may be sequestered long term. However, it is uncertain which root traits contribute most to soil C sequestration. We propose that root systems with greater relative abundance of fine roots will yield elevated rates of soil carbon sequestration, because these roots exude the most carbon. With this study we ask how the relative abundance of fine roots differs from switchgrass to big bluestem and does further variability extend to their cultivars. We collected soil samples from 10 year old plants in May 2018 (0-10cm depth) at Fermilab in Batavia, Illinois, and analyzed root size classes. Data shows that big bluestem has more fine (0-0.5mm) roots than switchgrass, which indicates it may be able to store more soil carbon. Our results provide greater understanding of how root traits in bioenergy cropping systems contribute to soil carbon sequestration for improved ecological sustainability.
The Role of Root Morphology in Soil Carbon Storage
Big Bluestem and Switchgrass are promising candidates for cellulosic bioenergy production. Increased removal of atmospheric CO2 is a key aspect of bioenergy production to ensure that more CO2 is removed than produced, via biofuel conversion. This makes it an ecologically sustainable process. Plant roots can contribute to atmospheric CO2 removal through the process of photosynthesis, transferring C from atmosphere to soil, where it may be sequestered long term. However, it is uncertain which root traits contribute most to soil C sequestration. We propose that root systems with greater relative abundance of fine roots will yield elevated rates of soil carbon sequestration, because these roots exude the most carbon. With this study we ask how the relative abundance of fine roots differs from switchgrass to big bluestem and does further variability extend to their cultivars. We collected soil samples from 10 year old plants in May 2018 (0-10cm depth) at Fermilab in Batavia, Illinois, and analyzed root size classes. Data shows that big bluestem has more fine (0-0.5mm) roots than switchgrass, which indicates it may be able to store more soil carbon. Our results provide greater understanding of how root traits in bioenergy cropping systems contribute to soil carbon sequestration for improved ecological sustainability.