Intensified Dryland Cropping Systems for Food and Fuel Production.

Intensified Dryland Cropping Systems for Food and Fuel Production

Reza Keshavarz Afshar and Chengci Chen*

Montana State University

*corresponding author: cchen@montana.edu; 406-433-2208 

Camelina has great potential to substitute fallow period in the predominant wheat-fallow (WW-FAL) cropping system in the Northern Great Plains. Production of biofuels on fallow land will benefit both, farmers and environment without creating any “food versus fuel” crisis. In a multiyear field study (2008-2015), we evaluated the sustainability of replacing fallow with camelina in WW-FAL rotation with respect to agronomic, economic, and energetic performance. We also examined how to improve the sustainability of camelina production via optimization of agronomic practices. Replacing fallow with camelina resulted in 13.2% wheat yield penalty whereas 907 kg ha^-1 of camelina was produced. Greater and annually biomass production thus enhancing soil organic matter, higher precipitation use efficiency, and protecting soil against erosion in WW-CAM indicates more agronomic sustainability of this system. WW-CAM also outperformed WW-FAL by 30% greater net energy output and similar energy efficiency. Despite agronomic, energetic, and ecological benefits, economic analysis revealed that at existing market prices and production costs, WW-FAL provides greater net returns to growers due to substantially lower variable costs. We found that there is a good potential to curb production costs of camelina through improving nitrogen fertilization use efficiency and reducing herbicide application. Beside lower production cost, higher grain price (the breakeven of $0.358 kg^-1) and/or greater grain yield are still essential to attract producers to plant camelina.