By Ruscena Wiederholt
“In the fall, we don’t mow like the beautiful archetypical farm that you see on postcards where everything is tidy and everything’s neat ” says Brett Grohsgal, co-owner of Even’ Star Farm, an organic vegetable, fruit and flower farm in Maryland. “If you want to have a farm that doesn’t have pollinator habitat, make it look like the postcard. Because you want messiness at the edges, and in a farm of this size 100 acres we can have a lot of edges of fields and a forest that are messy looking. And you intentionally don’t mow them. You intentionally let asters or goldenrods take over. You view milkweed as beneficial for monarchs and other species, too.”
Even’ Star Farm is an anomaly: It is teeming with insect life. In an increasingly hostile landscape, it’s a bug refuge filled with blooming cover crops, wildflowers and trees.
Unfortunately, not everywhere is so bucolically beneficial the decline of insect populations is unmistakable. Thirty-seven percent of insect species are decreasing globally, while abundance is dropping by nearly 4 percent annually.
A major player behind this demise is intensive agriculture, which causes habitat loss and pollution from pesticides and fertilizers. Along with threats such as disease, light pollution, invasive species and climate change, at least half a million insect species are facing extinction.
In an ironic twist, the loss of these little creatures comes back to haunt farmers in a vicious cycle of self-harm. After all, insects provide countless benefits to farms and surrounding ecosystems. Consequently, some farmers are grabbing the beetle by the horns and tackling insect collapse one flowery patch at a time.
The shortcomings of silent fields
Insects are the multitaskers of the farm field. “They provide a host of different ecosystem services,” says Emily May, an agricultural conservation lead at the Xerces Society for Invertebrate Conservation. “Those are things like pollination, decomposition, improving soil health, nutrient cycling and ensuring water quality. These are all important insect functions, and we are losing those species in abundance. Over the last 50 years, we have seen really marked declines.”
For instance, wild and honey bees pollinate around 85 percent of our cultivated crops. But due to their dropping numbers, we may already be losing 3 to 5 percent of our fruit, vegetable and nut crops from insufficient pollination.
But insects do more to help crops than just pollinate them. “Pollination is the one that most people think about when they’re thinking about insect benefits to farmers,” says Elijah Goodwin, the ecological monitoring director at Stone Barns Center, a nonprofit farm, education and research center in New York. “But I think biocontrol is another huge one and potentially even more important. A certain portion of crops are dependent on pollinators, but pretty much all crops have pest problems that can be mitigated by biocontrol.”
Indeed, biocontrol or using beneficial insects to eat or parasitize pests — provides $4.5 billion worth of pest control across the U.S. annually. And since most insects feed differently at different points in their lifecycles, with pest-eating larvae often maturing into pollen- and nectar-feeding pollinators as adults, farms can maximize the benefits by providing pollinator habitat even when the crops themselves don’t really need pollination.
Certain predatory insects like ground beetles also eat weed seeds that fall into fields, adds May. And there’s much more in insects’ toolbox.
“Another big one that’s very important in the livestock operation is all the flies and particularly the dung beetles that are helping to incorporate that animal manure back into your soil. ” says Goodwin. “So, the decomposers are actually another really super important group across the farm that helps waste material both vegetative and manure from overwhelming the system.”
Marginal solutions
With the benefits of bugs piling on, mitigating the dearth of insects on farms is crucial. For instance, at Even’ Star Farm, forgoing mowing allows flower strips to proliferate around fields providing important habitat for spiders, predatory insects and pollinators. Along with flowers, planting grassland strips along fields can also increase pollinator abundance.
“The more you can plant a diversity of native plants, the more you will have a diversity of native insects that are then able to turn out all these other functions for the farm,” says May. “So that’s things like hedgerows, filter strips and meadows.”
For example, filter strips, or buffer zones, are swaths of land between fields and water bodies that prevent sediment and runoff from entering the water, explains May. Filled with grasses or other vegetation, these areas also provide insect habitat. In fact, buffer zones in agricultural landscapes have 31 percent higher biomass of flying insects including pollinators and predators compared to fields that line waterways.
Similarly, planting trees near agricultural fields, such those used as windbreaks, provides food and shelter for bees. Unsurprisingly, this also benefits farmers since nearby forest fragments can boost crop yields by 15 to 20 percent.
A low-pesticide diet
In addition to these strategies, some farms have another trick up their sleeve. For instance, avoiding chemical use can spare beneficial insects the noxious effects of pesticides.
“We do not use pesticides and herbicides ” says Goodwin. “We always [try] to go with the most minimal intervention first, and then we step down. So, setting up a resilient system that regulates itself is the first line [of defense]; the second line of defense is maybe imported biocontrol; and the third line is mechanical interventions. And only if none of those solve the problem do we go to an organic, chemical solution. So that lack of herbicides and pesticides on the landscape has a huge impact.”
Likewise, Even’ Star Farm uses some organic pesticides, albeit selectively. While these substances have predominantly natural origins, they can still harm some beneficial insects. To compensate, explains Grohsgal, they avoid spraying blooming plants and refrain from spraying during times of the day when pollinators are active.
Blooming fields
Finally, the main course the farm fields themselves can benefit creepy crawlies.
For instance, Even’ Star Farm has a variety of crops like squash, kale and sunflowers blooming from spring to summer, which provide nectar and habitat for pollinators, says Grohsgal. As Stone Barns’s Goodwin explains, “The monocultural cropping, large monocrops, become a big issue because there’s just not a floral and vegetative diversity that support the resources for a lot of insects.”
In winter, Even’ Star Farm plants legume cover crops that flower in early spring. “We are short of nitrogen, so we use legumes as dominant winter cover crops,” says Grohsgal. “And you have not lived until you’ve walked in the field of crimson clover or vetch with thousands and thousands of bumblebees and butterflies and hornets and wasps and everything feeding on those flowers. You just haven’t lived because it’s so beautiful.”
Lastly, having a patchwork of vegetation provides another perk.
“The more diversity you see above ground, the more diverse those root systems are going to be below ground too, which also provides different habitat for insects that are living in the soil,” says May.
Grazers on the move
At the Stones Barns Center, they take a different approach: rotational grazing. By moving livestock and poultry like goats, cows, sheep and chickens daily, they’re able to maintain 350 acres of grassland in the adjacent Rockefeller State Park Preserve.
“You’re mimicking basically the system that the grasslands evolutionarily are adapted to, which is a very dense concentration of grazers coming through, but then they move on and there’s a long rest period,” says Goodwin. “And that’s what these grasslands are adapted to.”
While one spot is impacted by grazing, the vegetation is then allowed to recover. Thanks to the program, soil health has increased along with the abundance of native grassland plant species a.k.a. food for insects.
Research backs this up: Rotational grazing systems increase both butterfly and bumblebee abundance and diversity compared to continuous grazing due to a high cover of flowers. (That said, no benefit was found for ground beetles — which are important pest predators.)
The challenges of insect-friendly farming
Despite the rosy picture, promoting insect life on farms isn’t a walk in the park.
“If you don’t mow as much, you will have more weed species setting seed that’s undeniable,” says Grohsgal. “So, a lot of times, what the consumer is paying for in organic produce, the extra amount of money they’re paying for, is two things: manual weed control and increased failure of certain crops [due to pests].”
Additionally, the overall decline of beneficial, predatory insects has an unexpected side effect: more bugs. In fact, some insects mainly agricultural herbivores and nuisance pests have been increasing globally over the last few decades.
“As you lose species like wasps that control certain pests, you can have these outbreaks of pests in simple landscapes,” says May. “That’s one of the things that we work on, increasing habitat for a diversity of insects in working lands to promote that biological control the pest control that’s provided by beneficial insects.”
Grohsgal, for his part, has noticed increasing numbers of squash bugs, cucumber beetles and other pests on his farm. However, since his farm already has a variety of insect habitats, the proliferation may be for a different reason global warming. Climate change can increase food consumption and population growth of pests in certain areas. Plus, it allows them to expand their ranges and survive milder winters. In fact, researchers predict every (Celsius) degree of warming will increase global insect losses of wheat, rice and maize by 10 to 25 percent.
Grohsgal’s farm has adapted, though. They grow certain crops during winter when insect pressure is lower and no longer plant some squash varieties due to large losses.
Finally, a lack of policies protecting pollinators and their habitats, along with gaps in our scientific knowledge of many insect species, can be a hindrance to a bug-filled future.
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