Andrew McGuire   Courtesy geneticliteracyproject.org 

A farmer drastically reduces fertilizer applications, trusting soil biology to provide the needed nutrients. A crop consultant recommends a 10-species cover crop to replace fallow in a wheat rotation. An ag influencer promotes the idea that insect pests will not attack a healthy plant. All of these reflect what I call pop ecology,” a romanticized view of nature that promises trade-off-free farming but misleads agricultural decision making.

We’re all prone to idealizing nature. We see what appears to be stability and harmony, and then distill it into reassuring slogans: nature knows best,” everything’s connected,” and the balance of nature.” In agriculture, this pop ecology is found in mimic nature,” work with nature, not against it,” and a general bias against synthetic inputs. Nature knows best” is the foundation of organic farming and an underlying assumption in much of agroecology.

Pop ecology misleads crop production in three key ways: first, it trades scientific nuance for oversimplified certainty. Second, it treats unmanaged nature as the ideal standard and human intervention as suspect by default. Finally, it elevates the discredited concept of balance of nature.” Let’s take a look at how this plays out in nutrient management, biodiversity, and pest control.

Agricultural decisions are often influenced by romantic notions of nature—pop ecology—which is often at odds with field realities. Photo: Adobe Stock

The problem with natural nutrients

Pop ecology assumes that what works in unmanaged ecosystems applies directly to crop production. The critical difference? Export of biomass. In natural systems, nutrients cycle through plants, animals, and microbes, staying largely in place. In crop production, we export grain, forage, or vegetables every season, removing large amounts of nutrients with each harvest.

There’s often a bit of truth in pop ecology ideas. Soils do contain large amounts of nutrients in their mineral fraction. But mineral weathering and natural processes rarely deliver nutrients fast enough for modern crop yields. In addition to the rate problem, high-yielding production requires nutrient replacement—through manure, legumes (nitrogen only), or synthetic fertilizers. As ecologist Charles Krebs (2016) notes: The law of recycling is simple: input must equal output or the system decays.”

  In natural ecosystems, nutrients largely cycle in place. In cropping systems, harvest exports nutrients requiring replacement. Photo: Adobe Stock

The cost of believing otherwise is real. Growers who stop replacing exported nutrients will eventually see soil test levels decline, followed inevitably by yield losses. With phosphorus, this can take a long time because of previous fertilizer applications, giving the appearance of success (Menezes-Blackburn et al., 2018). However, when reserves are depleted, recovery requires not just resuming fertilization, but often higher rates to rebuild reserves.

Overselling biodiversity

Pop ecology takes conservation ecology’s more biodiversity is always better” message (Cardou and Vellend 2023) and applies it to farming, often promising benefits that don’t materialize in real fields. This oversimplification shows up everywhere: in recommendations for complex cover crop mixtures, soil inoculant products marketed to increase soil biodiversity,” and claims that crop diversity automatically leads to better pest control. At its base, it’s a variation of the appeal to nature fallacy: if something is natural, it must be good.

Reality is more nuanced. Recent ecological research challenges the biodiversity-equals-function assumption that has been gospel for decades. One analysis found no causal relationship between biodiversity and ecosystem functioning, just correlations (Schoolmaster Jr. et al., 2020). Another recent study, looking at natural assemblies of species rather than the random mixes used in many studies, found that increased species biodiversity in grasslands decreased productivity (Dee et al., 2023). Whatever the case may be in nature, when biodiversity does provide benefits in agriculture, it’s not the diversity itself that’s responsible, it’s specific interactions between specific species.

Which is better, a mixture or monoculture, depends more on the specific species and less on diversity levels. Photos: Andrew McGuire.

Consider cover crop mixtures. Research shows that the best mixture often performs no better than the best single species (Florence & McGuire, 2020), and the best monoculture is far easier to identify and manage. With intercropping of cash crops, only 44% of trials show consistent yield benefits (Jones et al., 2023). When we look at the actual mechanisms at work, we find that successful strategies aren’t about maximizing diversity, they’re about finding benefits from specific combinations like legumes paired with non-legumes in low-nitrogen soils. It’s not diversity that wins; it’s the right species doing the right things (MacLaren et al., 2023).

Even soil biodiversity defies pop ecology’s assumptions. Contrary to the agriculture degrades nature” narrative, recent surveys of European soils found cropland has higher microbial diversity than forests or unmanaged grasslands (Labouyrie et al., 2023). This wasn’t just bacteria, it held true for fungi, protists, nematodes, and arthropods. But lest we fall into pop ecology’s trap, this does not mean that cropland soils are functioning better. Just as with intercropping, what matters for soil function isn’t the number of species present, but which species and what they’re doing.

The balance of nature” problem in pest management

Pop ecology has had its deepest and longest influence in pest management. The balance of nature” concept, that natural systems are self-regulating and tending toward harmony, powerfully shapes pest control thinking (Worster 1994). It is often an unstated assumption in agroecology and in organic and regenerative agriculture (Ergazaki & Ampatzidis 2012) and found in ag publications, both educational and academic:

In unmanaged or natural ecosystems there is usually balance among organisms…”  Farming methods that focus on creating biologically balanced soil food webs… can reduce the need for synthetic fertilizer and pesticide inputs.” Michigan Field Crop Pest Ecology and Management (Cavigelli et al., 2000)

Proponents of sustainable agriculture frequently find solace in a vision of the natural world as inherently harmonious and balanced.” Vandermeer et al. (2010)

The balance of nature” is a comforting vision of how we think nature should be. Darwin, Rachel Carson, and Al Gore all appealed to it (Allchin 2014). Agroecologist John Vandermeer (2010) observes that the idea is frequently felt in the heart more than known in the head.” Even with inconsistent results, belief in balance-of-nature-type control persists (Tittonell 2014). Research has found that students, even college students, will continue to believe in the balance of nature even after receiving instruction to the contrary (Zimmerman and Cuddington 2007). We believe it because we want to believe it (Cuddington 2001). And yet, we must let it go.

Despite its popularity, most ecologists abandoned balance of nature” decades ago (Botkin 1990; Worster 1994; Cooper 2001; Kricher 2009; Simberloff 2014; McGill 2013). Rather than stable equilibrium, modern ecology emphasizes chance and change, what ecologists call contingency and disturbance (Drury 1998; White 2013). Natural systems reflect past events, unpredictable shocks, and continual shifts across time and space (Botkin 1990).