Nature’s laws have a way of making economic theories look inelegant. Mass production seems great on a blackboard, outstanding in a bar graph. But out in the open countryside, mass production often means monoculture; and nature’s prized variables of sustainability, balance and ecological vitality follow downward trajectories, falling off charts in sharp chalk-drawn descents.
Long-term studies of the land, such as those conducted by the Kellogg Biological Station over the past quarter century, demonstrate that plants are not widgets, and that economic laws easily provable in the classroom wither when planted in an agricultural field.
Simplification, for example, is no doubt an efficient way to install a fender on an assembly line, but it invites population explosions among pests and torrents of insecticide applications throughout the American heartland.
The remedy, Kellogg researchers confirm, is a return to plant diversity, nature’s enthralling kaleidoscope. A recent study led by researchers from Kellogg and Michigan State University (Werlinga et al.) puts it in specific terms:
“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.”
On the land, the most efficient economic model turns out to be not one devised by Henry Ford or Sam Walton, but rather the idea a wise band of gentlemen farmers once enshrined on the very symbol of profit and prosperity: E pluribus unum. Every great harvest draws from nature’s infinite diversity.