There are a handful of crops that feed the world, and corn (maize), rice and wheat are at the top of the list. Hundreds of millions of tonnes of these grains are grown every year. All three are annuals. They are harvested, the land is ploughed over and replanted in the spring.
As we have known for some time, this is difficult to sustain in the long term. Soil begins to lose its fertility, and we have to compensate with chemical fertilisers. When this runs off, it pollutes waterways and leads to marine dead zones. Ploughing disrupts the soil and risks erosion. And all this harvesting and replanting requires huge amounts of energy.
Grasslands, on the other hand, look after themselves. Nobody replants a prairie. They need no fertiliser or irrigation. Yet many of the grasses on prairies are grain-bearing, year after year, relying on deep roots that access nutrients and hold moisture. So would it be possible to farm perennial grains?
There is a reason why we’ve come to depend on annuals. Because they are replanted every year, our ancestors were able to cross-breed better crops. They lent themselves to selective breeding, and over hundreds of years we managed to nurture several important species into the high yielding crops that have become today’s staple foods. It would have been much harder to have done something similar with perennial grains.
Kansas based organisation The Land Institute believes that it’s not too late to switch tack, and that perennial grains could play a major role in future agriculture. They are working to cross-breed existing food crops with wild cousins, and domesticating perennial alternatives. So far they have tested a perennial wheat-wheatgrass hybrid. It can’t compete with the yields of traditional wheat just yet, but it’s early on in the process. Given another decade or two, and quicker still if we use genetic sequencing, we may have a revolutionary approach to providing our staple foods.