Environmental impact assessment of double- and relay-cropping with winter camelina in the northern Great Plains, USA – M Berti, B Johnson, D Ripplinger, R Gesch, A Aponte – Agricultural Systems 2017
Summary: Recent findings indicate that double- or relay-cropping winter camelina with forage or food crops can increase yield per area, improve energy balance, and provide several ecosystem services. Double-cropping can help balance food and energy production. The objective of this study was to determine the environmental impact of double- and relay-cropping systems as compared with monocultured maize and soybean in the Midwest, USA. Maize in monoculture had higher GWP (Global Warming Potential) than all other double- and relay-cropping systems studied. The higher emissions of double- and relay-cropping systems and maize can be explained by higher N fertilizer application, which led to greater field N2O emissions. Also, the additional sowing and harvesting of the double- or relay-crop increased CO2 emissions due to increased diesel use. Winter camelina as a monocrop had the lowest values in all impact categories, indicating camelina agricultural production phase has low environmental impact compared with maize and soybean in monoculture. Double- and relay- cropping systems increased primary productivity per unit area and biodiversity and reduced soil erosion potential. Increasing productivity with the additional environmental benefits of these systems may encourage more farmers to adopt sustainable agricultural practices.