Managing Water Resources in a Biofuel Economy.

One goal of our national security policy is to become more energy independent using biofuels.  Southeastern US agriculture can greatly contribute to biofuels with our usually favorable climate.  However, recent droughts have magnified competition with urban areas for available water resources.  Annually, the many states in the southeastern US receive greater then 1100 mm of rainfall.  The summer months usually have the greatest monthly rainfall from thunderstorms averaging approximately 120 mm per month.  However, thunderstorms are highly variable spatially.  Additionally, many soils in the coastal plain regions typically are sandy with root-restricting layers that reduce the available water holding capacity (usually ~25-50 mm storage).  Low water holding capacity soils coupled with variable rainfall typically result in short-term yield-reducing drought stress.  Previous research has shown that droughts during the growing season have a 50% probability of exceeding 20 days. 

 

Variable rainfall and soils with poor water holding capacity would also affect the potential biofuel crops grown in the region.  Biofuel crops would need to be grown with these water limitations taken into consideration.  Irrigation would be required to reduce the impact of these short-term droughts and to produce a steady, reliable stream of crops for sustainable biofuel production. 

 

The presentation will focus on the effect that water shortage will have on potential biofuel crop production along with the demands that biomass will place on water resources in the southeastern US.