Wild Plants to the Rescue
Efforts to domesticate new, high-yield, perennial grain crops require patience and persistence—but such plants could transform agriculture
The Next Grains
Grains form the basis of the global food system, and they can relatively easily be processed into liquid fuels. Many new possibilities for crop development can be found in these plants. Perennial grains developed from tropical plants are the most obvious area for further research. We do not know how well the temperate-grassland–adapted species we are working on might perform in the humid or arid tropics, but even if they can be bred for adaptation to those climates, there is a wealth of indigenous vegetation likely to produce better candidates.
Saline environments are even more challenging. More than 4 million square kilometers of cropland are already salinized, and additional land is at risk, mostly as a result of years of irrigation. Although plant breeders are having some success in increasing the salt tolerance of standard crops, others have predicted that strong salt tolerance is genetically complex and that domestication of wild halophytes (salt-loving plants) might be more successful in the long term. At least one halophyte has traditionally been harvested for grain by the Native Americans of the Colorado River delta: Distichlis palmeri.
Woody crops have been traditionally placed in a separate category from grains, but some, like chestnuts and hazelnuts, have food value similar to plants more usually recognized as grains. Breeding for reduced height and threshability might make it possible to harvest these nuts nearly as easily as corn. Any plant with starch-, oil- or protein-rich reproductive structures that can be harvested, transported and processed like a grain is a candidate for investigation.
Most humans will be seed-eaters for the foreseeable future, it seems. Alternatives to seed-based food systems, such as algae or enzymatic conversion of cellulose, have been proposed, but they have received almost no funding. Fortunately, we live on a planet with more than 220,000 species of seed-bearing plants. These species occupy almost every global habitat across a wide span of plant forms and sizes. The crop base of the world’s food system could be dramatically broadened in the next several decades—if other organizations can replicate the conditions Wes Jackson created at the Land Institute, in which projects are given, in his words, “the freedom to fail,” along with sufficient time to prove their potential.
- Cox, T. S., et al. 2002. Breeding perennial grain crops. Critical Reviews in Plant Sciences. 21:59–91.
- Cox, T. S., J. D. Glover, D. L. Van Tassel, C. M. Cox and L. R. DeHaan. 2006. Prospects for developing perennial grains. BioScience 56:649–659.
- Cox, T. S., D. L. Van Tassel, C. M. Cox and L. R. DeHaan. 2010. Progress in breeding perennial grains. Crop and Pasture Science. 61:513–521.
- DeHaan, L. R., D. L. Van Tassel and T. S. Cox. 2005. Perennial grain crops: A synthesis of ecology and plant breeding. Renewable Agriculture and Food Systems 20:5–14.
- Fedoroff, N. V., et al. 2010. Radically rethinking agriculture for the 21st century. Science 327:833–834.
- Foley, J. A., et al. 2011. Solutions for a cultivated planet. Nature 478:337–342.
- Glover, J. D., et al. Harvested perennial grasslands provide ecological benchmarks for agricultural sustainability. Agriculture, Ecosystems & Environment 137: 3–12.
- Glover, J. D., et al. 2010. Increased food and ecosystem security via perennial grains. Science 328:1638–1639.
- Glover, J. D., J. P. Reganold and C. M. Cox. 2012. Agriculture: Plant perennials to save Africa’s soils. Nature 489:359–361.
- Godfray, H. C. J., et al. 2010. Food security: The challenge of feeding 9 billion people. Science 327:812–818.
- Kahn, P. C., T. Molnar, G. G. Zhang and C. R. Funk. 2011. Investing in perennial crops to sustainably feed the world. Issues in Science and Technology. http://www.issues.org/27.4/kahn.htm
- Kowalski, R., and J. Wiercinski. 2004. Evaluation of chemical composition of some Silphium l. species as alternative foodstuff raw materials. Polish Journal of Food and Nutrition Sciences 13:349–354.
- National Research Council of the National Academies. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, D.C.: National Academies Press. pp. 249–251.
- Pearlstein, S. L., et al. 2012. Nipa (Distichlis palmeri): A perennial grain crop for saltwater irrigation. Journal of Arid Environments 82:60–70.
- Pimentel, D., et al. 2012. Annual vs. perennial grain production. Agriculture, Ecosystems and Environment 161:1–9.
- Scotland, R. W, and A. H. Wortley. 2003. How many species of seed plants are there? Taxon 52:101–104.
- Rozema, J., and T. Flowers. 2008. Crops for a salinized world. Science 322:1478–1480.
- Van Tassel, D. L., L. R. DeHaan and T. S. Cox. 2010. Missing domesticated plant forms: Can artificial selection fill the gap? Evolutionary Applications 3:434–452.
- Weaver, J. E., and L. A. Stoddart. 1935. Response of the prairie to the great drought of 1934. Ecology 16:612–629.
- Zerai, D. B., et al. 2010. Potential for the improvement of Salicornia bigelovii through selective breeding. Ecological Engineering 36:730–739.
- Zhang, Y., et al. 2011. Potential of perennial crop on environmental sustainability of agriculture. Procedia Environmental Sciences 10:1141–1147.
» Post Comment