Research Project:  Crop and Weed Responses to Increasing Atmospheric Carbon Dioxide

* ''Title: Kudzu Pueraria montana (Lour.) Merr. Var lobata: a new source of carbohydrate for bioethanol production'' *

Authors # Sage, Rowan - UNIV OF TORONTO # Coiner, Heather - UNIV OF TORONTO # Way, Danielle - UNIV OF TORONTO # Runion, George # Prior, Stephen # Torbert, Henry # Sicher, Richard # Ziska, Lewis

*Interpretive Summary: *

Among invasive plants, Kudzu, a vine species imported from Asia to control soil erosion, now occupies over 8 million acres, primarily in the southeastern United States. Kudzu is a weed, but can produce a high volume of carbohydrates. As such, it could be considered as a potential new source for biofuel. The authors measured the amount of kudzu in naturally-infested fields in three states, Alabama, Georgia, and Maryland.

Below-ground biomass in Alabama exceeded five tons per acre. Based on the yield data and carbohydrate concentration, the authors estimated wild kudzu in Alabama and Georgia could produce two to four tons of carbohydrate per acre. This would rival carbohydrate production? from corn and sugarcane? fields, but without the costs associated with planting, fertilizer and pesticides.

Wild kudzu has the potential to economically supplement existing bioethanol feedstocks, which could be of local significance to the rural U.S. economies where it grows. These results will be of interest for policy makers, scientists, agronomists and stake-holders interested in the potential utilization of plant-based biofuels.

*Technical Abstract: *

The authors determined the amount of standing biomass of kudzu ''Pueraria montana var. lobata'' in naturally-infested fields in Maryland and Alabama, USA. At each site, carbohydrate content of root, stems and leaves were evaluated. For a third site from Georgia, the carbohydrate content of roots of varying diameters was evaluated. Below ground, biomass in Alabama exceeded 13 tons per hectare, and contained an average of 35% fermentable? carbohydrates (sucrose?, glucose and starch). Roots from Georgia of all size classes contained over 60% fermentable carbohydrates. Stems were only 1-2% carbohydrates. Biomass and carbohydrate levels in roots from Maryland were low compared to plants growing in Alabama and Georgia, being on the order of 5 tons of roots per hectare with 20% nonstructural carbohydrate.

Based on the yield data and carbohydrate concentration, the authors estimate wild kudzu stands in Alabama and Georgia could produce 5 to 10 tons of carbohydrate per hectare, which would rival carbohydrate production from corn and sugar cane fields, but without the costs associated with planting, fertilizer and pesticides. Wild kudzu thus has the potential to economically supplement existing bioethanol feedstocks?, which could be of local significance to the rural economy of the southeastern USA.

=External links:=

Kudzu Pueraria montana Lour. Merr. Var lobata: a new source of carbohydrate for bioethanol production

Submitted to: Biomass and Bioenergy?

Publication Type: Peer Reviewed Journal

Publication Acceptance Date: April 1, 2008

Publication Date: January 5, 2009

Citation: Sage, R.F., Coiner, H.A., Way, D.A., Runion, G.B., Prior, S.A., Torbert III, H.A., Sicher, Jr., R.C., Ziska, L.H. 2009. Kudzu [Pueraria montana (Lour.) Merr. Var lobata]: a new source of carbohydrate for bioethanol production. Biomass and Bioenergy. 33:57-61.