We are all accustomed to adopting new versions of familiar products like phones, computers, and cars. But what about taking on new versions of our most important food crops? Corn, wheat, and rice all have something in common that hasn’t changed since their domestication: an annual life cycle. This characteristic aided their domestication in the hands of Neolithic farmers by allowing quick improvements in yield due to the short time span between generations. Interestingly, these major grain crops have lesser known perennial relatives that did not lend themselves as well to domestication, but otherwise produce similar useable parts. Recently, humans have turned to perennial relatives of our annual staple crops in the hopes that they can help solve some of our most pressing agricultural issues.
Growers face common challenges including water shortage, erosion, high fertilizer costs, and lack of soil nutrition. These problems are caused and/or exacerbated by cultivation practices tailored to plants with annual life cycles. Annual root systems are relatively shallow and short lived. Therefore, a lot of the water and fertilizer applied to annual crops is lost in the form of runoff. By comparison, perennial plants have deeper root systems that remain in place for multiple years in a row (see image below). They help mitigate the above agricultural issues by holding soil in place, maximizing water use efficiency, and improving nutrient uptake. Many non-grain commercial crops are inherently perennial, require fewer agricultural inputs, and do well on marginal land. Examples include grapes, olives, pidgeon peas, and many common fruit and nut trees.
Despite the aforementioned crops, the world still lacks commercially viable perennial alternatives to the world’s most important grain crops. The catch with perennial grain species is that in order to produce extensive root systems and store energy for next year, they must divert energy away from seed production, thus lowering yields. It shows that the saying, “there is no such thing as a free lunch” holds true in the plant world. Currently, in order to get the ecological services of an extensive root system, you have to compromise on yield. Most growers on good agricultural land are not yet forced to make that compromise, but those on marginal land might take it into consideration. Breeders are working on backcrossing domesticated grains with their wild perennial relatives to close the yield gap between perennial and annual varieties. Breeding and commercializing these varieties has proven to be technically challenging and underfunded, but there are some notable signs of progress.
The Land Institute, founded in 1976 by Wes Jackson in Salina, Kansas is a leader in the research and implementation of perennial agriculture for cereal crops. The institute faces the challenge of creating varieties with adequate yields while also maintaining perennial characteristics. Some breeders say they are still 15 or 20 years away from developing varieties that are suitable for main stream agriculture, but signs of progress are imminent. Dr. Hu Fengyi of the Yunnan Academy of Agricultural Sciences has bred a variety of perennial rice that has produced yields for the last three years of roughly equal quantity to annual rice in the region. Nevertheless, projects on this time scale do not lend themselves well to the three year federal grant cycle, and their mission does not exactly jive with the business model of large agricultural companies, so there will likely be some financial hurdles to overcome.
Regardless of the challenges, one has reason to be optimistic that recent advances in bioinformatics and marker assisted breeding techniques combined with mounting pressure from environmental hardships such as soil degradation and water shortages could tip the balance in favor of perennials sooner than people might think. Commercial viability of a crop is not decided in a vacuum, and depends on more than just the crop itself. It is a function of many economic, environmental, social, and biological factors that change from year to year. Additionally, there is an opportunity to get smarter about matching specific varieties to specific land use situations. Proto-varieties of perennial grains will probably not be able to compete on prime agricultural land in the near future, but prime ag land seems to be a static (perhaps diminishing) resource. In an approaching era of agricultural innovation, marginal land could prove to be a vast and profitable new niche for agricultural companies. The development and implementation of hardier crops such as perennial grains are likely to see huge payoffs.