When you were growing up, how often did you have to clean your windshield? And how often do you have to do that now?
The universal answer is that remarkably few insects goo up our windshields today, even relative to a few decades ago.
The insect apocalypse is worldwide in scope, and is directly related to how we produce our food. One study estimates that we’ve lost 76 percent of insect biomass over the past 27 years. Two primary drivers of this staggering biodiversity loss are habitat loss associated with the industrialization of our food system, and the unintended consequences of agrichemical use. Reforming our food system gives us a powerful tool for combating this extensive biodiversity loss, and regenerative food systems can overcome many of the drivers of insect loss.
Ineffective Pest Control
Integrated pest management (IPM) was fighting a battle it could never win. In 1959, it became clear that our over-reliance on chemical pesticides was failing, and some scientists in California devised a systematic approach to pest management that could reduce chemical use and increase crop yield. Rachel Carson’s book Silent Spring then provided the fuel for widespread promotion of IPM that continues to this day. But it didn’t work. More pesticides than ever are put into the environment. And arguably, pests are as big a problem today as they were 60 years ago. Regenerative farmers around the world are dispelling one of the central myths that IPM was trying to solve: that pests in agriculture are inevitable, and that pesticides are an effective pest management tool.
Pests aren’t inevitable. Outbreaks are caused by monoculture cropping conditions, and by removing diversity and network connectivity from an agroecosystem. Most pests are early successional organisms that take advantage of stressed crops grown in monocultures that are devoid of biotic resistance to the pest. Practices that eliminate life give a platform for continual pest resurgence. Essentially, IPM says, “You produce food in this way; here’s a better way to manage a problem that’s created by this production method.” Farmers practicing regenerative agriculture say, “The way you’re producing food is wrong. And when you fix the way you produce food, pests will no longer be a problem.”
Regenerative Agriculture Principles Provide an Alternative
Regenerative agriculture has roots in conservation agriculture and adaptive management, and relies on four central principles to achieve pest-free crops and livestock: Eliminate tillage; replace bare soil (always have living roots on the ground); encourage plant diversity (some plant diversity is better than none, and more is better than less); and integrate plants and animals on farms. These four underlying principles are achieved through myriad practices that can be adapted to a local or regional environment to attain a functioning farm system. Regenerative is organic, but organic isn’t necessarily regenerative. The end result is that by focusing on soil health and promoting biodiversity on farms, regenerative farming produces healthy food profitably. Regenerative principles fundamentally restore diversity and reduce disturbance to an agroecosystem within a functioning farm operation. As such, the effects of regenerative principles on pest populations are well-founded in ecology. Here’s how regenerative principles deter pests without endangering them and contributing to the insect apocalypse.
1. Eliminate tillage to increase life in the soil. Soil disturbance (such as tillage) removes life from the soil, and disrupts the balance among organisms that remain in the soil, reducing their ability to function. The functions of soil life that are related to pest management include making the crop able to resist pest pressure (by increasing the immune function of the plant, and the vigor of the resulting crop plant), and increasing the biotic resistance to pest proliferation (entomopathogens, predators, parasitoids, and competitors). Although tillage has been espoused as a tool for managing soil insect pests for generations, there’s little evidence that it actually works, and in many cases, it increases pest pressure.
2. Replace bare soil with living roots. In 2009, we ran a study in which we planted a winter cover crop (slender wheatgrass) in a cornfield, and then killed it directly before corn planting. This was back when cover crops were still regarded as “fringe” to mainstream land managers. Then, we infested the corn plants with corn rootworms and monitored biodiversity. (As the name suggests, the little beetle grubs live in the corn roots.) The result was fewer pests compared with the corn plots preceded by bare soil. This surprising result was produced because insect predators were much more abundant in the cover-cropped field. But the corn plants were also different in this study; the root structure was changed. So as the rootworms aged, they had to leave the corn root to find more suitable host roots, and when they did so, they were attacked by legions of predators. Just having roots in the ground from one plant species and some residue on the surface (and it wasn’t a lot) was enough to allow insect communities to achieve balance. The ways that insect communities function are difficult to understand, but these complex communities work. And their function all starts with having many plant species on the ground all year long.
3. Encourage plant diversity. Restoring diversity to farmland is essential for pest suppression. The diversity of most other organisms is directly tied to plant diversity, abundance, and biomass within a habitat. Thus, practices that promote plant diversity on a farm provide clear benefits to pest management. The number of plant species and whether specific species are needed are practical questions frequently asked by farmers. One study suggests that other ecosystem services start to maximize around 10 to 16 plant species in a community, but we don’t have good data on insect pest management in this regard. Insect communities are complex, and that complexity challenges the selection of the perfect suite of plants for conserving the “best” insects. Certainly, it’s never been demonstrated that there can be too many plant species in a habitat, from an ecosystem service perspective.
There are a lot of agronomically feasible ways of increasing plant diversity on a farm. It begins with crop diversity. Varying the varieties of a crop is a first step, and long crop rotations and including intercropping schemes are great ways to increase plant diversity in cropland. Diverse cover crop mixes and interseeded cover mixes help cover bare soil and add diversity. Diversifying field margins, shelterbelts, and wetlands can offer an additional source of plant diversity on a farm, and those effects can spill over into adjacent cropland.
4. Integrate crops and livestock. Animals are essential to a healthy biological community on the land, especially a healthy plant community. Their dung recycles nutrients and feeds the next generation of plants. Livestock, through stimulation of plant growth, direct consumption of plants and pests, and trampling action, are an effective management tool for many pests when crop plants and pastures are directly grazed. In addition to reducing costs associated with pest management, well-managed livestock integration in cropland also increases the resilience and natural resource base of a farm. Integrating different livestock species into a single field has many benefits for the agroecosystem; the benefits of mixed livestock systems for pest management remain to be demonstrated, although anecdotal reports from farmers suggest that this is the future of livestock integration.
In the end, regenerative food systems are one of the most effective approaches we have for battling planetary-scale problems, such as pollution, climate change, human health problems, and biodiversity conservation. Although the pest management benefits of regenerative principles have a strong scientific basis in ecology, it’s farmers who’ve learned how to put these ecological fundamentals into practical and functional farm systems. This illustrates the crucial importance of how these two sectors of the agricultural community need to work together so regenerative agriculture can rise to dominance in our society.
Dr. Jonathan Lundgren is director of the Ecdysis Foundation, which uses science and education to fuel the regenerative agriculture movement. He also runs the regenerative Blue Dasher Farm in Estelline, South Dakota.
