A December study from Cornell University’s Department of Entomology provides more evidence that hemp is a crucial resource for struggling pollinators, and hemp farmers agree.
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Researchers in New York State have shed new light on the little-known world of pollinators in the hemp industry.
By staking out hemp flowers and catching everything that buzzed, entomologists from Cornell University showed that hemp farms in the Fingerlakes supported sixteen different species of bees. This diversity could be a buffer for a group of pollinators in steep decline.
The study, in the journal Environmental Entomology, backs up a Colorado State University study from last year that documented twenty-three unique kinds of bees on hemp flowers in northern Colorado.
Most of the visitors were one of two usual suspects, the domesticated European honey bee, Apis mellifera, and the familiar wild bumblebee, Bombus impatiens, but the wide variety of other wild bees included species like Augochlora pura, a solitary sweat bee which nests in rotting logs.
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The Cornell researchers found that hemp is a crucial source of pollen in late summer, a time of scarcity for bees when other crops and done flowering and agricultural fields have little to offer.
This research comes at a time when pollinator populations are in global decline, with potentially dire consequences for the world’s food supply, according to the National Institute of Food and Agriculture.
The studies help clarify the role that hemp might play in the relationship between agriculture and biodiversity. America’s hemp industry is exploding — according to the USDA, the acreage of land under cultivation in the U.S. has grown a hundredfold since restrictions were first loosened in the 2014 Farm Bill.
The most recent Farm Bill in 2018 officially turned hemp from a controlled substance into an agricultural commodity, adding rocket fuel to the boom.
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That bees and hemp get along like bears and honey comes as no surprise to “Wild” Bill Billings, co-founder of the Colorado Hemp Project and one of the growers who in 2014 helped inaugurate the first legal harvest in America. “Oh, bees love hemp,” he said. “Absolutely, I’ve seen bees so fat they couldn’t even fly, or they were flying in slow motion.”
Caveat: CBD doesn’t count
Billings and his clients, who cultivate thousands of acres in Colorado, grow traditional industrial hemp, with both male and female plants. Hemp pollen comes from the flowers of the male hemp plant, and bees gather it to feed their larvae, and in the case of domestic honeybees, their workers — hence the familiar bulky saddlebags of pollen on their hind legs. Female hemp plants have small flowers, but unlike many flowering plants, they do not produce nectar, and so aren’t good bee food.
This is an important distinction because much of the new hemp being grown is for the surging cannabidiol market — the key ingredient in low-THC extracts and edibles. Hemp farmers focused on the extract market grow only female hemp plants, and so their fields are not useful for bees.
A 2017 survey of the global hemp industry in the journal Trends in Plant Science noted that “currently, there is a major discrepancy in crop value depending on product type,” and that “the value of CBD far exceeds that of seed or fiber.”
“We grow regular industrial hemp, not CBD hemp,” he said. Their hemp, destined for products like hemp seed oil, building materials, or hemp protein powder, does provide a pollen windfall because the fields include male plants. The recent pollinator studies focused on these kinds of farms.
Is pest-control bee-friendly?
The fairly hands-off, low-pesticide approach that characterizes hemp farms, which is good for pollinators, might not last. The authors of the Colorado pollinator study noted that “as a novel crop, currently there are few insect pests reported in hemp fields. However, this can change as the cultivation expands.”
If more aggressive pests or higher intensity farming practices accompany hemp’s switch from a controlled substance to an agricultural commodity, the benefits seen by pollinators could shrink or even reverse.
A recent paper in the Journal of Integrated Pest Management raises this concern, rattling off a list of known pests like the corn earworm, the hemp russet mite, and the cannabis aphid.
“The situation regarding pesticide use on hemp in the United States has been chaotic,” the authors wrote, which “has created enormous confusion, and remains a major impediment to the development of effective pest management on the crop.”
Hemp has long been considered a superstar of sustainability, but as the industry scales up this assumption will be tested.
A classic 1999 study by Canadian agricultural scientists rated oilseed and fiber cannabis (typical varieties of industrial hemp) behind only ginseng and alfalfa in all-around environmental friendliness.
It is a hardy, naturally pest-resistant plant that is low maintenance compared to other crops.
Billings, the Colorado hemp consultant, said most farms he works with do fairly little pest management now. Asked about his strategy, he said jokingly that it was to “pray — pray that the hail don’t come, and you pray that you don’t have too bad a bug infestation.”
The EPA currently approves just ten pesticides for use on industrial hemp, and only one is a conventional chemical. The others are organic farming standbys like neem oil and insecticidal soap. Even some of these, however, have shown to be possibly detrimental to bees, and as the EPA continues to consider permits for new applications on hemp, there is the prospect of a more toxic landscape for pollinators.
Instead of designing a pest control program from scratch, one newcomer to the hemp industry, Main Street Farm in Cortland, New York, is wrapping the new crop into a pest management and pollinator program that already exists for its other ones, including vegetables, cut-flowers, and blueberries.
“We take a holistic management approach on our farm that includes the entire agroecosystem,” said Adrienne Traub, one of the Main Street’s farmers and its certification coordinator. “Crop rotations are an integral part of our pest management plan. By moving crop families each year, we reduce the possible build of pests in that soil that can over-winter.”
Main Street Farm, which has a USDA organic certification, also makes an effort to build up wildlife habitat within and around crops. This jibes well with the findings of the Cornell study, which took place in the same region.
The entomologists found that “the number of wild bees visiting hemp declined as the proportion of agricultural cover in the landscape increased,” indicating that hemp is most helpful to bees when it exists as part of a diverse system.
Main Street Farm’s efforts to diversify their landscape include providing food and habitat for beneficial insects. “We planted a pollinator strip that runs the length of the farm that includes many varieties of native annual and perennial flowers,” Traub said. “We also are actively working to increase the biodiversity of our hedgerows.”
Eventually, Traub hopes to one day have access to varieties of hemp that are especially pest resistant, but “at this point, there are no pest-resistant cultivars commercially available.”