This week, when you look out your window, there is a good chance you will see monarch butterflies fluttering back through the Twin Cities area as part of their astonishing annual multigenerational migration between North America and Mexico. And as they do, I'll think back to my boyhood on a central Illinois farm, when the plant these magnificent insects love to eat was the bane of my existence — and I, in a sense, was the bane of theirs.

Monarchs eat milkweed and milkweed only; deprive them of this plant and they cannot survive. But milkweed's deep roots also compete with crops for water and nutrients. So every June, my dad would assign my cousins and me to walk the soybean fields and pull by hand the weeds he hadn't been able to plow under with his tractor.

This was hard labor, and we hated it.

There was, then, perhaps some irony when in 1996 the company I joined after earning my doctorate in microbiology and biochemistry — Monsanto — began marketing Roundup Ready soybeans. These genetically modified seeds enabled farmers to use Roundup herbicide, generically called glyphosate, to control many weeds, including milkweed, without harming their beans. The combination of the genetically modified seed and glyphosate also produced many environmental benefits.

But not for monarchs, because the herbicide helped rid farmers' fields of milkweed better than boys like me ever could. And in these and ensuing years, several other developments also began to harm the monarch: government policies that encouraged crop expansion for biofuel to replace the harmful gasoline additive MTBE; logging in the monarch's Mexican forest home and freakishly bad weather, among others.

Eventually, it became apparent that this combination of forces was shrinking the monarch's annual migration between Mexico and Canada. And today, the monarch has become an emblem of the dramatic conflict between farming's role in feeding humanity and its impact on biodiversity and the environment.

Fortunately, however, all kinds of interests — environmentalists, wildlife and conservation groups, farmers, agricultural companies, and government — are now joining forces to protect this beautiful creature. Earlier this year, for example, the U.S. Fish and Wildlife Service pledged $1.2 million for habitat restoration, research and seed production. And we at Monsanto recently announced that we have committed $4 million to support grants to the National Fish and Wildlife Foundation and other organizations to aid experts working to benefit the monarch and its habitats.

These are strong initial steps, but more is needed to address this very complex challenge. For example:

• We need to build on the efforts of groups like Forests for Monarchs to restore the monarchs' winter home in the mountain forests of central Mexico.

• We need to understand how to ward off pests, like the debilitating parasite that's infecting nonmigratory monarchs in Florida and is threatening to spread to migratory monarchs.

• Most important, we need to restore milkweed populations. Not in farmers' fields, where they would interfere with the goal of feeding humanity, but in many other places.

This third item will take years. But it can be done.

For example, federal and state departments of transportation already are reassessing mowing and vegetation management guidelines along country roads, highways and other places where milkweed can grow. As a next step, pasturelands, land managed under the federal Conservation Reservation Program (CRP) and other appropriate areas should be planted.

Likewise, through the good work of groups like Monarch Watch and Monarch Joint Venture, we've learned that certain areas along the monarch corridor, especially in the Upper Midwest, are critical. But now more research is needed to determine exactly where habitat restoration efforts should be focused.

In addition, the U.S. Department of Agriculture can encourage the inclusion of milkweed in soil conservation and habitat restoration programs by nonprofit organizations — groups such as Xerces Society, Pheasants Forever and Quail Unlimited — which already are active in this effort. City gardens, parks and urban landscaping also can be managed in more monarch-friendly ways.

To accomplish all this, we'll also need technical innovations, such as large-scale milkweed seed production. And we'll need to continue to innovate in agriculture itself. Because by embracing advances such as molecular breeding, genetic modification, microbials and precision agriculture, we can sustainably produce more food on less land — enabling us to turn more farmland back into habitat for monarchs and other creatures. "Sustainable intensification" can help us achieve an enormous win-win — for humanity, which needs food, fiber and energy, and for the environment.

I'm optimistic. The monarch — that wondrous creature with which I've somehow been involved my whole life — is a powerful motivator.

Robert T. Fraley is the chief technology officer at Monsanto.