Project Number: 6413-13000-010-00
Project Type: Appropriated

Start Date: Nov 29, 2007
End Date: Nov 27, 2008

Objective:
Specific objectives are to develop technology and management guidelines to maximize production of varieties of sugar cane that are most suitable for energy/fuel production while: 1. Minimizing water use and negative impacts to the quality of drainage waters, including exploring wastewater reuse technologies to support biomass energy production. 2. Maintaining soil fertility and maximizing soil carbon storage and carbon neutrality of biomass energy production systems in humid temperate and subtropical environments. 3. Minimizing sediment and nutrient loss and potential erosion and/or subsidence of associated coastal ecosystems.

Approach:
Field studies will be conducted in close cooperation with the ARS Sugarcane Research at the Ardoyne Farm site, as well as the LSU Ag Center in Baton Rouge. Field experiments will be conducted to evaluate and select an integrated system of best management practices (BMPs) for a sustainable production system for energy-cane as a biomass source for biofuels that will protect soil and water resources from degradation and/or pollution. On-farm practices to be included in the integrated system will include alternative strategies for management of: drainage, tillage, agrochemical (fertilizer and pesticide) application, and post-harvest residue management. For examples, fertilizer will be applied in split applications or by different methods, pesticide applications will include different methods and timing based on weather forecasts, sufficient amounts of post-harvest residue will be retained in the field to reduce soil erosion, and optional controlled-drainage methods will be implemented. Evaluation and selection criteria for BMPs in the integrated production system will be based on sediment, nutrient and other agrochemical transport in drainage flows, maintenance of soil fertility and carbon storage, energy-cane biomass yield, and economics to implement and operate the integrated practices. Modeling and simulation studies will be conducted (e.g., with DRAINMOD-N2, RZWQM, AnnAGNPS, etc.) to predict hydrology, agrochemical loss, soil erosion, and crop (biomass) yield for various BMP combinations for the energy-cane production management system. Field data will be used to calibrate the models to improve predictions. The simulation technique will permit evaluation of a larger number of BMP combinations for an optimum production system. Simulations at sub-watershed scale will be conducted to predict the scope of application needed for the integrated management system to impact water quality parameters at the larger scale. One or more models will be modified to input weather forecast records (for specific sites) to also evaluate benefits (if any) of adjusting the timing of agrochemical application based on the forecast probability of rain for the day following planned application. Future complementary studies will be conducted on cooperating farms by monitoring, sampling and analyzing flow in small streams or drainage channels that carry runoff from energy-cane cropland. Diversion of drainage channel flow through wetland resource areas will be implemented, if possible at selected sites, to evaluate further reduction in stream flow nutrient loads (particularly nitrate). Additional future complementary studies will be conducted to evaluate the potential for using nutrient enriched drainage waters diverted into associated coastal ecosystems to restore and maintain coastal wetlands and marshes; this practice would reduce nutrient enriched flows to the Gulf that contribute to hypoxia.