How Perennial Crops Save Our Soil

These days, there’s a lot of talk about which agricultural practices are safe and sustainable. GMOs, organics, small- or large-scale operations, local or industrial farms – these all are considerable topics on how we cultivate crops. Jerry Glover, agroecologist at The Land Institute and a National Geographic Emerging Explorer, argues that these concerns are in fact subordinate in relation to one decision: whether to grow annual or perennial crops. Whether the goal is to restore food security in impoverished countries, reverse desert expansion in U.S. prairie lands, or reduce energy and water consumption, the influence of perennials is profound.

4 Advantages of Perennial Crops

Many perennials represent what are considered to be staple crops: grains and legumes. These include wheat, rice, maize, soybeans, peas, and beans. Cropland for grains and legumes represents 68 percent of the earth’s agricultural acreage, and they provide as much as 80 percent of human calorie consumption. Currently, these crops are annuals, meaning that they die after harvest and must be reseeded each year. Because their life cycles are short, annuals have shallow roots and require extensive tending. The longevity of perennials, on the other hand, presents a multitude of advantages for people and for the planet.

1. Improve Soil Quality

Because perennials endure year after year, their root systems have time to mature and deepen. These deep roots create a haven for bacteria that, in turn, enriches the soil with nutrients. Deep roots also have better access to groundwater, which means they require less irrigation and are better equipped to handle drought. What’s more, their intensive root systems combat topsoil erosion, runoff, and nutrient loss – conditions that transform otherwise arid and barren terrain into fertile land.

Perennial roots are incredibly deep and complex compared to their annual counterparts. Image via The Land Institute.

Perennial roots are incredibly deep and complex compared to their annual counterparts. Image via The Land Institute.

2. Minimize Labor & Energy

Deep-rooted plants with long lifespans are more efficient and self-sufficient. Subsequently, perennials require fewer resources to function, including labor, fuel, fertilizers, and water. While farmers from any region can appreciate these benefits, perennials are especially influential in poor countries where small farms readily collapse if resources are limited.

3. Reduce Greenhouse Gasses

Using less fuel on farms equates to fewer greenhouse gas emissions. However, perennials furthermore combat greenhouse gas by dissolving carbon into the soil. When carbon is stored in soil instead of air, the quality of the soil improves while global warming is mitigated.

Perennial wheatgrass flourishes at The Land Institute’s home base of Salina, Kansas. Image via Wikimedia Commons.

Perennial wheatgrass flourishes at The Land Institute’s home base of Salina, Kansas. Image via Wikimedia Commons.

4. Enhance Biodiversity

Most common agricultural practices are intrusive to the natural world, restricting the ability of different plants and insects to grow and thrive. Nature has flourished throughout the ages by establishing complex ecosystems based on symbiotic relationships. Perennials hold the potential to return us to a more natural system where rigorous tilling and replanting is substituted with agriculture that essentially resembles prairie land. In such an environment, multiple plants grow with complementary nutrient needs, and insects serve as natural predators to common pests.

Making the switch to perennial crops requires identifying plants with characteristics suitable for agriculture, such as producing adequate yields and having fewer leaves and shorter stems. These plants will not appear overnight and require studying the relatives of common annuals that can then be crossbred or domesticated – essentially grooming the plants for desirable traits. Jerry Glover and The Land Institute are leading the way in research in this field. During the upcoming years, we can look to them to change the future of farms as we know it.

Featured Image: Banana trees, like these on a farm in rural India, are perennial crops. Image via Mira John.

Copyediting by Daniel Cordero

About The Author

Molly is a student at the Boston Architectural College obtaining a Masters in Sustainable Design. Originally from Mount Desert, Maine, Molly is a lover of both the natural world and city living and hopes that the two can coexist practically, responsibly, and beautifully. Molly's interests lie particularly in food supply and nutrition.