Greenhouse Gas Life Cycle Analysis of Biochar Effects On Marginal Land Conversion to Switchgrass Production.

The establishment of switchgrass on marginally-productive agricultural lands allows for the production of bioenergy feedstocks while providing excellent soil erosion control. Biochar additions to soil sequesters carbon and the organic matter addition can potentially improve the soil properties and increase plant biomass production. A field experiment to investigate the benefits of two biochar application strategies during switchgrass establishment has been initiated in the fall of 2011 at four locations in central Pennsylvania (two excessively drained, two poorly drained).  Biochar was produced from switchgrass biomass, and 10 ton ha^-1 were either tilled into soil before switchgrass planting or are being applied as four annual side-dress applications. Switchgrass biomass production and quality, soil C partitioning, nitrous oxide emissions, and other properties are being monitored in the field. Additional laboratory investigations are being conducted to further indentify biochar characteristics and the influence of the char on soil properties. These include quantification of carbon respiration from char and char-amended soils and the measurement the effect of char addition on soil water holding capacity. ¹³C signatures of carbon dioxide respired by char-amended soils indicates a very small contribution from char, confirming that char is a very stable form of organic C. Data obtained form the field study will be used to support life cycle analysis.