Nature’s laws have a way of making economic theories look inelegant. Mass production seems great on a blackboard, but out in the open countryside mass production often means monoculture, the planting of a single crop on millions of acres.
In such an environment, ecological stewardship based on principles of sustainability, balance and plant diversity rarely takes root.
Mass production is an efficient way to install a fender on an assembly line, but it has invited population explosions among insects and concentrated use of chemical pesticides across the American heartland, where landscapes of corn and soy extend as far as the eye can see.
One study by researchers from Michigan State University’s Kellogg Biological Station, published in the journal Proceedings of the National Academy of Sciences, discovered that agricultural land in the U.S. Midwest is becoming less diverse with each passing year. That sets in motion a downward ecological spiral, according to Tim Meehan, a University of Wisconsin (Madison) entomologist who participated in the study.
“Two things drive this pattern,” he explained. “As you remove natural habitats, you remove habitat for beneficial predatory insects, and when you create more cropland you make a bigger target for pests — giving them what they need to survive and multiply.”
The study outlined the myriad benefits of plant and ecological diversity:
Habitat stability and perenniality matter.
“Conventional, annual cropping systems disrupt communities of soil microbes and beneficial insects through yearly tillage and use of nutrients and pesticides, reducing the ability of these organisms to cycle nutrients, remove greenhouse gases from the atmosphere and suppress pests.”
Plant diversity matters.
“Habitats with multiple plant species support greater biodiversity and ecosystem services compared to habitats dominated by a single plant. [Agricultural] producers could incorporate plant diversity into annual crops through the use of diverse crop rotations and cover crops.”
Landscape perenniality and diversity matter.
“Agricultural landscapes that contain a mix of annual crop and perennial habitats will support more species and greater rates of many ecosystem services compared to landscapes dominated by one or a few annual crops . . . Such diverse landscapes may support more types of organisms, ensuring that a decline in one species is offset by the presence of another that can fill in to provide a service. In addition, any given species may meet their different needs by using different habitats (for example, some predatory beetles feed within wheat fields but shelter in grassy margins in the winter); diverse landscapes could provide for these needs.”
The solution is to restore the natural balance. Kellogg researcher Doug Landis, a Michigan State University entomologist, advises farmers to offset monoculture fields by adding the diversity of native perennials, some of which could even be used to generate bioenergy: “Perennial crops provide year-round habitat for beneficial insects, birds, and other wildlife, and are critical for buffering streams and rivers from soil erosion and preventing nutrient and pesticide pollution.”
These farmers have rediscovered a fundamental truth: Every great harvest, vibrant landscape and beautiful garden draws from nature’s infinite diversity.