24
Sep
Research on Thousands of Organic and Chemical-Intensive Farms Illustrates Stark Difference in Toxic Chemical Use
(Beyond Pesticides, September 24, 2021) Recent research out of California sought to compare (and quantify) differences in total pesticide use, and in use of pesticides of specific concern, across conventional and organic agricultural fields in the state. The research team, from the Bren School of Environmental Science and Management, University of California, Santa Barbara, finds an 18–31% likely reduction in spraying of pesticides on organically managed fields compared to conventional, and a 27% likely reduction in use of pesticide products with high acute human toxicity for organic versus conventional fields. Readers may be gasping, and thinking, “Wait, what?! I thought organic farming does not use pesticides! Help?”
There is a world of difference between the pesticides used in organic and in conventional production. Though conventional growers are allowed to use thousands of synthetic compounds on their crops, seeds, and soils — no matter their toxicity, as long as EPA has permitted them — Certified Organic growers are permitted to use only “natural” or naturally derived pesticide products, and a very limited number, at that. Organic growers may use any of the products listed in “The National List of Allowed and Prohibited Substances,” as established by the NOP’s (National Organic Program’s) National Organic Standards Board. In this case, natural materials subject to “chemical change” may be used if they do not cause adverse effects, are organic-compatible, and deemed essential. Growers may not use the prohibited substances on that list (except as outlined below).
Organic producers are not left “defenseless” against pests, but operate within stringent limits on what is allowed — a virtual handful of compounds, as compared with the 17,000 pesticide products on the market and available to conventional growers. The allowed compounds for organic production, overall, are far less toxic for human and environmental health than many of the conventionally deployed pesticides. And, although the National Organic Standards (NOS) default to a prohibition of synthetic pesticides, the National List process permits very few synthetic materials in certain categories of agricultural production. All natural substances are allowed, unless prohibited. The synthetic substances are limited to those “used in production and contains an active synthetic ingredient in the following categories: copper and sulfur compounds; toxins derived from bacteria; pheromones, soaps, horticultural oils, fish emulsions, treated seed, vitamins and minerals; livestock parasiticides and medicines and production aids including netting, tree wraps and seals, insect traps, sticky barriers, row covers, and equipment cleansers; [. . .] [Section 2118, Organic Foods Production Act (OFPA) (c))(1)(B(i) [U.S.C. 6517] National List.]
The researchers assert in their paper, published in Nature Communications, that “Notwithstanding popular perception, the environmental impacts of organic agriculture, particularly with respect to pesticide use, are not well established. Fueling the impasse is the general lack of data on comparable organic and conventional agricultural fields. . . . Organic agriculture is commonly perceived to be chemical-free, though organic as a regulatory definition, at least in the U.S., generally restricts the type of inputs applied rather than the amount. The regulation does not itself require chemical-free farming [per Section 2118 of OFPA (cited above)], and organic compliance does not always imply low toxicity to ecological or environmental endpoints. For example, organic-acceptable active ingredients such as copper, pyrethrin, and azadirachtin are toxic to aquatic organisms. Furthermore, since pesticide residue testing often focuses on synthetic chemicals of high human toxicity and field-level data on production or certification are rarely available, little is known about pesticide use practices on organic fields.”
The researchers sought to understand more granularly the environmental pros and cons of organic vs. conventional production systems. There are myriad lenses through which to evaluate such environmental pros and cons; this team focused on “how being organic relative to conventional affects decisions to spray pesticides and, if spraying, how much to spray.” They write, “Pesticide use, though only one component of environmental or health aspects of organic production, is of paramount importance to consumers due to potential environmental and human health impacts such as water quality contamination and consumer and farm-worker wellbeing.”
The paper acknowledges the toxic history of synthetic pesticide use and its impacts on human and environmental health, noting, “Historically, widespread use of persistent, broad-spectrum, and bioaccumulating chemicals such as organochlorines and organophosphates had severe negative impacts on humans, other mammals, and birds. . . . As those risks were increasingly recognized, a new generation of chemicals was developed with a particular focus on reducing human-health risks. While the development and uptake of these pesticides have limited direct mammal and bird mortality . . . many remain highly toxic to other organisms. Further, population-level ecological effects through food web interactions or sub-lethal impacts (e.g., behavioral changes and reduced migratory navigation) remain a concern for higher taxa.” Beyond Pesticides recommends that readers review its coverage of the Impacts of Pesticides on Wildlife — many of which, though not acutely lethal, are nevertheless extremely damaging.
The team began with this question: does the “reduction in negative ecological and environmental impacts on-field compensate for the reduction in yields and increased yield variability that ha[ve] been observed for most organically produced crops in actual field surveys?” They also write, “Understanding the difference between organic and conventional fields in real-world settings is crucial for understanding the merits of organic production practices at scale.” (Beyond Pesticides refers readers to information about the performance of organic production methods here, here, and here.)
Globally, agricultural activity uses approximately 40% of arable land; a mere 1.5% of that land is farmed organically, though both the acreage devoted to, and the sales of, organic food are rising dramatically. Since 2000, for example, organically managed agricultural land has grown from 15 million to 73 million hectares (37+ million acres to 180+ million acres).
This study reviewed data from 2013 to 2019 for nearly 100,000 agricultural fields in Kern County — a very large sample — 9,100 of which were organically managed fields. (The number of fields and acreage of each varied year-to-year, so these metrics represent averages across the time period.) The organic fields in the study were roughly 44% smaller than conventional fields. The chief crops grown on the organic fields included carrot, potato, lettuce leaf, and tomato; almond, pistachio, grape, and alfalfa were primary on conventional fields. Seven to 11% (over the course of the seven years of data) of the production in the county came from Certified Organic fields.
Of their methods, the team writes, “We harmonize and aggregate several data sources to identify the spatial location of organic crop fields and rely on unique, field-level crop and pesticide use data . . . to understand pesticide use differences. . . . Due to the number of different products and chemicals applied in our study area, we rely on pesticide use and coarse metrics of ecotoxicity based on the pesticide product label. . . . We evaluate (1) overall differences between organic and conventional fields with respect to the decisions to spray and how much to spray for total pesticide use and pesticides of potential hazard to a range of different endpoints, (2) crop-specific differences in pesticide use decisions between organic and conventional fields for five crops commonly grown with both organic and conventional practices, and (3) how adjusting for yield gaps may influence the overall results.”
On average, researchers conclude, organic fields in the County are more likely (than conventional fields) to be pesticide-free — with the relative absence of spraying (18–31% reduced likelihood) implying a reduction of ecotoxicological impacts. They also noted the 27% lower likelihood of use, in organic fields, of compounds with high acute human toxicity. (High toxicity is defined as EPA acute toxicity category one or two in the U.S. Environmental Protection Agency’s [EPA’s] rubric.) The study also asserts that spraying of organic fields uses similar amounts of pesticides as that done by conventional farms in the study; however, what is being sprayed is quite different.
For crops that are commonly grown in the county both organically and conventionally, the study notes a consistent reduction in the probability of using any pesticides. The study homed in on pesticide outcomes for two crops — carrots and grapes. It found that a switch to organic production protocols reduced the probability of using a given class of pesticide by 27–51% for carrots, and 21–23% for grapes. A switch to organic for carrots reduced the use of most types of pesticides by 80% (± 9%) to 98% (± 1%), and increased use of low-toxicity chemicals by 72% (± 12%). Switching to organics for grapes, however, increased (NOS allowed) pesticide use by 126% (± 34%) to 286% (± 98%). It should be noted that grapes are notoriously vulnerable to a variety of fungal infestations, in particular.
The research concludes: “Our analysis provides four main innovations: (1) for the first time, we have isolated the spatial location of thousands of organic fields using production and pesticide use data; (2) organic fields are generally smaller in size, part of larger farms, and on better soil than their conventional counterparts; (3) organic agriculture, on average, uses less pesticides than conventional production and this manifests in a lower probability of using any pesticides, and similar use on fields that do spray; and (4) different crop types vary considerably from the average, and in some cases, the reverse relationship is present and significant [such as that noted for grape production].”
The study does underscore the complexity of analyzing what is actually happening on organically farmed fields (at least in this one county in California, but very likely in many locations). Organic agriculture is not magically “free” of all chemicals — as the study notes, for example, about copper, pyrethrin, and azadirachtin [the active ingredient in neem oil], above. (Indeed, all living organisms and non-living materials are chemically based!)
But organic regenerative practices do nearly eliminate the use of highly toxic, synthetic chemical compounds, as well as their myriad downstream impacts on ecosystems, non-target organisms, and the health and safety of waterways and water bodies. Further, organic agriculture provides multiple ecosystem functions and services at greater economic benefit to farmers than conventional, chemical-intensive cropping systems, as a recent study demonstrated. And food produced organically is healthier for humans. Note the relationships of pesticide exposures to health compromise at this web page on pesticide induced diseases.
The reality of the use of NOS-approved pesticides in organic agriculture may have been a small shock to some readers, but it is worth emphasizing, once again, that both the nature and the number of allowed compounds in Certified Organic agriculture are far more benign, and fewer (by orders of magnitude), respectively, than those registered by EPA and used on conventionally grown crops. The prevalence and toxicity of synthetic pesticides is — and has been — so extreme that recent research has found that their legacy is showing up as toxic pesticide residues on some organic farms, emphasizing the threat of a history of weak regulatory standards, and the urgent need to transition to organic.
Beyond Pesticides is also vigilant about the details and strength of the National Organic Standards — see the webpage, Save Our Organic — because those details matter. The NOS are a powerful tool to shape the future of agriculture and of the environment broadly, as this August 2021 Daily News Blog article underscores. Regular readers will know how frequently and adamantly Beyond Pesticides drives home the point that a transition to organic regenerative agriculture (and land management broadly) is imperative and urgent.
At nearly every meeting of the NOS Board, there are proposals for substances to be added to The National List of Allowed and Prohibited Substances. Beyond Pesticides regularly reviews these, writes about them in its Daily News Blog, weighs in with NOSB, and encourages the public to do the same. In Spring 2021, for example, the NOSB dealt with a petition to permit use of antibiotics in organic pear and apple production, and Beyond Pesticides advocated to keep antibiotics out of organic. The Fall 2021 NOSB meeting is scheduled for October 13–21; keep an eye out for Beyond Pesticides discussions of items on that agenda that may need public advocacy.
Source: https://www.nature.com/articles/s41467-021-25502-w#MOESM1
Nature Communications is an open access journal that publishes high-quality research from all areas of the natural sciences. Papers published by the journal represent important advances of significance to specialists within each field.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
