Whenever soil is plowed and prepared for another growing season, soil erosion is a problem. One long-term approach to reducing agriculture-related erosion is being explored by plant geneticist Wes Jackson, president of the Land Institute in Salina, Kansas. Jackson maintains that the single most beneficial new development in agriculture would be the development of food crops that do not need to be replanted every year.

Annual plants, such as wheat and corn, live only one season and must be replanted each year, which causes enormous disruption to the soil. In contrast, perennial plants do not require plowing. Perennials have a longer growing season than annuals: They can continue producing roots and storing energy even after harvest, and they often emerge earlier in spring than annuals. In addition, they can rely on root systems that were established in previous years, so they can allocate more resources in the current year to the production of stems, fruits, and seeds. All of these characteristics make them more productive than annuals.

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Researchers at the Land Institute are exploring a variety of ways to grow crops in systems that mimic the natural world. Using a combination of conventional selective breeding and technology, they are attempting to convert annual species such as wheat, sorghum, sunflowers, and corn into perennials. At the same time, they are collecting wild perennials such as wheatgrass, then domesticating them and selecting for higher seed yield, size, and quality. Through these efforts, researchers hope to assemble communities of perennial plants, animals, fungi, and microorganisms that will be stable, productive, and resistant to insect pests and diseases.

The ultimate goal of the Land Institute is to develop sustainable crops that will produce sufficient amounts of food for harvest by humans, reduce soil erosion, and reduce or eliminate the need for synthetic fertilizers, pesticides, and irrigation. The researchers have already managed to double the size of seeds of a species of wheatgrass and increase its seed production by 20 percent without losing other important qualities of the plant. They have also had some success in crossing specially treated domesticated sorghum with perennial sorghum varieties to produce progeny that are both fertile and perennial.

Critics contend that it may take many decades to develop perennial seed crops that provide usable produce. Jackson doesn’t seem overly concerned about this. According to Jackson, “If you’re working on something you can finish in your lifetime, you’re not thinking big enough.”

Critical Thinking Questions

References

Glover, J.D., et al. 2010. Increased food and ecosystem security via perennial grains. Science 328:1638–1639.

The Land Institute: http://www.landinstitute.org.