Luring local pollinators to farms can pay for itself in four short years, according to a new study.
Right now in Washington and Oregon, 380,000 honeybee hives are at work pollinating cherry, pear, and apple orchards. Last month, a million hives—three-quarters of the nation’s entire stock of commercial honeybees—were pollinating almonds in the Central Valley of California. Pollination by insects is an essential service, necessary for 71 percent of the top 100 crops worldwide. But it has also become alarmingly expensive and uncertain, as colony collapse disorder and other problems have doubled or tripled the cost of renting honeybee hives.
Why not let native pollinators do the same work for free?
That might be a good idea, except that populations of wild pollinators have also collapsed, largely because intensive agriculture has eaten up huge swaths of former habitat, with no end in sight. When researchers in Utah and Illinois recently looked at four North American bumblebee species, they found that their geographic range had shrunk by as much as 87 percent, and population by as much as 96 percent, with a significant share of the loss having occurred within the past 20 years.
The developing concern over a different kind of national security—pollinator security—recently led the White House for the first time to include a pollinator garden in its plantings, with the aim of supporting bees and monarch butterflies and drawing attention to their crucial role in food production. A group called Make Way for Monarchs is lobbying for large-scale federal action ahead of National Pollinator Week in June. (It has also called on Americans to “join us in a day of action and contemplation for imperiled pollinators” today.)
Of potentially more lasting impact is that some farmers have begun to ask whether introducing flower strips, hedgerows, and other forms of habitat in the margins of their farms might bring back wild pollinators—and ensure that their crops will get the pollen they need to bear fruit. A new study in the Journal of Applied Ecology adds to the growing evidence that it can work.
Michigan State University entomologists Brett Blaauw and Rufus Isaacs looked at blueberry farms over a four-year period. Planting a one-acre patch of perennial wildflowers cost about $700, with a state program picking up much of the tab. The wildflowers, grown on unused land next to 10-acre patches of blueberries, didn’t seem to make much difference in the first three years, as the plantings became established. But by year four, farms with flower patches had a 33 percent higher pollination rate than farms that relied solely on honeybee colonies. The payback timetable was also attractive, even setting aside the state subsidy. The increased value of the crop in year four was sufficient to pay for the initial cost of planting, with the likelihood that benefits would continue indefinitely thereafter.
The fourth-year results in the new study were particularly revealing, according to Blaauw, because that year was a terrible one for pollination. Nonetheless, the farms that relied on a diversity of wild pollinators suffered much less than farms that relied on trucked-in honeybees. The wild pollinators served as a sort of insurance policy, he says.
Beneficial insects also took up residence in the plantings and, though the study doesn’t try to quantify the benefit, these newcomers seem to have gone to work picking off crop pests. One farmer in the study, Richard Rant, of West Olive, Mich., liked the results well enough to add wildflowers throughout his farm. He reported that he was able to cut back from 10 or 12 insecticide applications on his blueberries each year to just two or three in some years, at a savings of up to $6,000 a year.
Up to now, conventional agriculture has been headed in the opposite direction. Over the past 15 years, development of herbicide-tolerant crops has led to a massive increase in spraying of Roundup, wiping out all other plant life—that is, habitat for wild pollinators—on more than 100 million acres of row crops in the Midwestern grain belt alone. At the same time, the federal mandate for corn-based ethanol has resulted in the planting of crops, just since 2008, on 23.6 million acres of marginally productive land formerly set aside for conservation—more lost pollinator habitat. That change has resonated in the amount of insurance payouts when plantings on such marginal land fail: Taxpayers had to pay $8.3 billion for crop failures in the 294 counties with the highest rates of conversion, according to a 2012 study by the Environmental Working Group.
Experiments like the one in Michigan have increasingly demonstrated the value of taking a step back—for instance, by planting hedgerows for pollinators alongside almond fields in California, or flower strips among the mango trees in Africa. The U.S. Department of Agriculture now works with the Xerces Society, an entomological group, to help farmers figure out which wildflowers or other pollinator habitats are likely to work best on a given terrain or with a particular crop. Many states also have programs to help farmers pay for wild pollinator habitat. Michigan, for instance, has so far subsidized 2,000 acres of wildflower plantings, in theory supporting 20,000 acres of crops.
But the scale of agricultural intensification so far dwarfs all these efforts. Until that changes, the fate of wild pollinators—and of the food on our tables—remains at risk.