Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 28, 2004
Publication Date: October 31, 2004
Citation: Liebig, M.A., Johnson, H.A., Hanson, J.D., Frank, A.B. 2004. Soil carbon under switchgrass stands and cultivated cropland. IN: Agronomy Abstracts (No. 4262). ASA, Madison, WI. Technical Abstract: Switchgrass (Panicum virgatum L.) is considered to be a valuable bioenergy crop with significant potential to sequester soil organic carbon (SOC). A study was conducted to evaluate soil carbon stocks within established switchgrass stands and nearby cultivated cropland on farms throughout the northern Great Plains and northern Cornbelt. Soil from forty-two paired switchgrass/cropland sites throughout MN, ND, and SD were sampled to a depth of 1.2 m and analyzed for soil carbon in depth increments of 0 to 0.05, 0.05 to 0.1, 0.1 to 0.2, 0.2 to 0.3, 0.3 to 0.6, 0.6 to 0.9, and 0.9 to 1.2 m. Soil organic carbon was greater (P<0.1) in switchgrass stands than cultivated cropland at 0 to 0.05, 0.3 to 0.6, and 0.6 to 0.9 m. Differences in SOC between switchgrass stands and cultivated cropland were especially pronounced at deeper soil depths, where treatment differences were 7.74 and 4.35 Mg ha-1 for the 0.3 to 0.6 and 0.6 to 0.9 m depths, respectively. Greater root biomass below 0.3 m in switchgrass likely contributed to trends in SOC between switchgrass stands and cultivated cropland. Switchgrass appears to be effective at storing SOC not just near the soil surface, but also at depths below 0.3 m where carbon is less susceptible to mineralization and loss.