Managing a second-generation crop portfolio through sustainable intensification: Examples from the USA and the EU

Sustainable intensification of agricultural systems has been suggested - in addition to reducing waste and changing consumption habits - as a way to increase food, feed, fuel, and fiber security in the twenty-first century. Here we describe three primary strategies of agricultural intensification - conventional intensification, temporal intensification, and spatial intensification - and how they can be used to manage and integrate food and second-generation crop portfolios. While each strategy has individual merits, combining them to meet case-specific targets may achieve optimum results. Multiple experiments and examples from the USA and the EU illustrate the potential of combining these approaches for agroecological intensification that can provide ecosystem services while maintaining or increasing economic output, thus striking a balance between 'land sparing' and 'land sharing'. Management strategies will vary by the types of markets available, e.g., food, fuel and/or ecosystem services, and the scale of markets supplied, e.g., small heat and power vs. large cellulosic ethanol. Future research should holistically and methodologically evaluate the trade-offs between different management strategies.