As the global population grows toward 10 billion people, we need to find ways to better manage the farmland that we have, while also removing CO2 from the atmosphere, said Evan DeLucia at JGI’s 13th Annual Genomics of Energy & Environment Meeting in San Francisco, Calif. As director of the Center for Advanced Bioenergy and Bioproducts Innovation (CABBI),a DOE Bioenergy Research Center at the University of Illinois Urbana-Champaign (UIUC), DeLucia noted that second-generation biofuel crops like the perennial grasses Miscanthus and switchgrass can efficiently meet emission reduction goals without significantly displacing cropland used for food production because, in addition to producing a usable product, these crops sequester carbon in soil. But the annual row crops that dominate agriculture around the world, particularly intensive maize-soybean rotation, have considerable negative environmental impacts, including significant greenhouse gas emissions.
Stressing the need for transformative, and not merely incremental land-use solutions, he advocated perennial polycropping, where herbaceous and woody plants and trees—nut trees with berry bushes, for example—are integrated with food crops throughout a field. He presented data showing that nitrogen loss form such a system is very low compared to maize-soybean rotation, and projected that the combined caloric yield could reach one-third the yield of a conventional system. And, he added, there hasn’t even been much effort to date to genetically modify chestnut or other nut trees to maximize yields.