CDR LTER

Bioenergy could be an important part of the solution to the projected climate problems of the future, and in addition could provide auxiliary ecological services. The project described here aims to parameterize expected benefits of diverse prairie biofuel plantations for groundwater quality, and also to further evaluate its biofuel potential. This project, done in cooperation with the USGS, grows out of purely scientific discoveries in other Cedar Creek experiments. We know that diverse prairie systems are better able to retain inorganic nitrogen than monoculture systems (e.g., Dijkstra etal. 2007). However, nitrogen is just one pollutant of many being delivered to surface-water and ground-water from agricultural systems. There are a number of others including phosphorus, pesticides, and veterinary pharmaceuticals. This fact combined with the rising demand for corn grain ethanol could lead to further declines in the water quality of agricultural regions in the United States. Perennial vegetative buffers, in particular diverse prairies and/or hay (CRP), are proposed solutions. The vegetation in such buffers can be used for biofuel and simultaneously appear to be attenuate leaching of agricultural compounds through the unsaturated zone to groundwater. This 3-year cooperative USGS and UMN study will (1) examine the ability of prairies and hay (CRP) to attenuate leaching of agricultural compounds to ground-water (2) compare biofuel production of four cropping systems: diverse prairie, hay (CRP), corn grown with chemical fertilizer, and corn grown with a combination of manure and chemical fertilizer, (3) provide for future investigations into microbial antibiotic resistance and (4) provide a better understanding of the unsaturated zone hydrology and shallow groundwater recharge at Cedar Creek. The project will take place in the E120 field.