In Praise of Bt Corn and RoundUp Ready Soybeans


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Marc BrazeauMarc Brazeau | Editor | Food and Farm Discussion Lab | @eatcookwrite

[6200 words – 30 minutes reading time]
If you haven’t watched the new documentary Well Fed yet, I highly recommend it. Dutch film-maker Karsten de Vreugd has standard issue lefty/urban attitudes about organic and pesticides and he and his friends think GMOs are a bad idea. Except for one friend, his best friend. Hidde Boersma is a science journalist with a PhD in molecular biology who challenges de Vreugd to rethink his views.

The film follows them around the world as they seek a balanced look at the issue, with Boersma doing a fantastic job of making the science of genetics and plant breeding accessible to the rest of us. After making stops to interview a local representative of Greenpeace and some other anti-biotech advocates, they travel to Bangladesh to track the success of Bt Brinjal in reducing insecticide use and increasing yields and profits for smallholder farmers. Then it’s on to the Philippines to track the progress of Golden Rice and understand the potential it holds for reducing the devastation caused by vitamin A deficiency. Greenpeace has been vehement and aggressive in its opposition to Golden Rice, which the organization sees as a Trojan horse to bring GE crops into the developing world.

These encounters are effective in bringing de Vreugd around in seeing genetic engineering in agriculture outside of the typical, narrow criticisms around industrial agriculture and monocrops, corporate control and profit. I have to admit I got a bit frustrated with what I see as an all too common strategy of persuasion regarding the benefits of biotech in ag. Playing up the potential of virtuous, NGO-style biotech crops for the Global South is an important, but incomplete strategy in making the case for biotech. It’s something I’ve seen over and over, distancing from industrial agriculture in order to get someone to see the issue in a different light. I get it. It works. It worked on me. But it’s not enough. Biotech advocates also need to make the case for herbicide tolerance and insect-resistant commodity crops instead of deflecting away from the issue. They need to sing the praises of Bt corn and Roundup Ready soybeans. I don’t mean to criticize the film, which I loved, and that probably wasn’t the place for it, but somebody has to make the case for the role biotech has played in industrial agriculture. That’s what we’re going to do now.

well fed 4 25 18

Industrial agriculture isn’t going anywhere. The question is what sort of industrial agriculture are we going to have?

There are over 7 billion people living on this planet, most of them in cities. In the US we have over 330 million mouths to feed with less than 2% of the population engaged in farming. For better or for worse, we live in an industrial society. Barring some top-to-bottom reorganization of our economy, we are going to have an industrial food system. If there is a set of political reforms that would enable an economically viable mass form of neo-peasant farming in developed countries, I haven’t heard anyone make the case for what they would be.

Should there be vibrant, regional systems of small and mid-sized farms producing the freshest, most delicious fruits and vegetables, wines, meats and cheeses serving farmers’ markets, farm-to-table restaurants and local grocers? Absolutely! But they are never going to displace production ag in a substantial way.

The Pioneer Valley in Western Massachusetts is about as well poised for locavorism as any place in the US. They have tons of wonderful farms in a fertile valley cut by the Connecticut River. They have two college towns with exactly the kind of demographic of citizens dying to support local farms — including commitments from university and college dining commons to source local food. A recent estimate put their local consumption at 12%. That’s only about a half million people under ideal conditions. How you would get as high as 12% in Boston or New York is unclear to me.

Maybe that’s looking at a goal that’s a little too bespoke. Let’s zoom out to a simpler problem. One of the central criticisms of our current industrial food system is that it relies too heavily on just two crops — corn and soy. It would be better for our health and the environment if we had a more varied diet and more diverse crop rotations. The food system would be more resilient with greater diversity, and we’d need less synthetic fertilizer planting more legumes. Doubling production of the next top eight grains and pulses would be a worthy reform of our industrial food system.

Here’s a little back of the envelope math – 2016/17 averages of acres planted for grains and pulses that could most easily displace corn and soy in rotations:

Dry edible peas and beans: 2.9 million acres
Oats: 2.7 million acres
Rye: 2.0 million acres
Lentils: 1 million acres
Millet: 500,000 acres
Chickpeas: 400,000 acres
Barley: 270,000 acres
Total – 9.8 million acres

So if you could double demand for these crops, you could ostensibly displace a whopping 5 million acres each from the 90 million acres each of corn and soybeans.

Which would be no small feat.

So now we would only be producing 85 million acres of corn and 85 million acres of soybeans.

We’ll put aside any lack of viable plan for doubling consumption of oats, rye, dried beans, dried peas, lentils, millet, chickpeas and barley. Wave a magic wand getting rid of ethanol and maybe we’d get corn production down to 60 million acres.

So, even after two giant magic wand reforms (and to be clear, I’d love to see both happen, but I don’t see a clear path to get there), if you want to make farming in the United States more sustainable, outside of livestock production, making corn and soy production more sustainable is still where the most leverage is.


Chart by the author.

In any effort to making farming more sustainable, staple crops are where the action is, especially the four crops on the left hand side of the chart above.

Consider the words of Mark Lynas, speaking at the Oxford Farming Conference earlier this year:

Although I don’t want to get into the glyphosate debate here, it is also clear that the adoption of herbicide-tolerant crops has helped shift farming away from more toxic herbicides and facilitated no-till and conservation agriculture.

But as a contribution to global sustainability these improvements have been marginal, trivial even. Genetic modification has not yet reduced fertiliser use, contributed significantly to higher yields, or done anything to address world hunger.

Compared to revolutionary changes that we all hope are on the way — in the speech he mentions nitrogen fixation in non-pulse crops and the biofortified crops in the pipeline to address major nutritional deficiencies — I suppose the contributions of insect resistance and herbicide tolerance could be considered marginal.

Nevertheless, compared to any other innovations over the last three decades, I would propose that the Bt trait in corn and cotton, and the Roundup Ready trait in corn, soybeans, alfalfa, canola and sugar beets are two of most consequential innovations in making agriculture more sustainable. The only thing I would rate ahead of the Bt and Roundup Ready traits is the wide adoption of no-till and conservation tillage during this period. And of course, Roundup Ready crops played a significant role in reducing tillage a major reason RR was has been so consequential.

Soybeans in no-till field. Image credit: Wikicommons

To underline a key component in this judgement, it’s only innovations in the major staple and commodity crops that can scale to major significance. The only other arena where breakthroughs could be as consequential is in meat production. When Bt in corn reduces insecticide use, in the US that’s happening across something close to 90 million acres, and on nearly 13 million acres for Bt cotton. When Roundup Ready displaced tillage and other more impactful herbicides in soybeans, that’s happening on nearly 70-90 million acres of soybeans depending on the year. Roundup Ready crops account for nearly 200 million acres of US cropland. In one paper that tried to model the impact of Roundup Ready soybeans on reductions in tillage found “the adoption of conservation tillage and no-tillage have been about 10% and 20% higher, respectively, due to the advent of glyphosate tolerant soybeans.” That’s several million acres of no-till and conservation soybean production. For comparison, in 2016 there were 124,591 acres of organic soybeans in production, with the vast majority in conventional tillage. If organic farming researchers could finally figure out how to make no-till in organic soybeans viable with the roller crimper, that new innovation might be applied up to something like 100,000 acres. Over two decades after the adoption of Roundup Ready crops in conventional no-till systems, they are still struggling to make no-till viable in organic production at scale.

Beyond the shifts in tillage, the improved profile of herbicide use, the large reductions insecticide use across hundred of thousands of acres of farmland, there are the less talked about reductions in fuel use that follow from reducing tillage and fewer tractor passes for spraying along with the carbon savings from lower fuel use and carbon sequestration from no-till. But the most overlooked benefit and perhaps the most consequential is the reduction in pesticide poisonings for smallholder cotton farmers in developing countries. Those reductions in illnesses number in the millions and we’ll try to quantify that at some length. I also include impacts on farm income for the middle-income country of Argentina and the developing nations of China, Pakistan, India and South Africa because sustainable farming costs money. It’s much easier when you can invest in the right infrastructure, better seed, and plan on a longer time horizon.

Impacts in Developing and Middle Income Countries

Every year, the agricultural and natural resources industry consulting firm updates their magisterial literature review and data analysis [PDF] on the global impacts of GE crops. It takes the peer reviewed research literature and public data pulls it into a systematic attempt at quantification. I’ve asked people I respect about the quality of this work. And no one I’ve talked to has found any reason to see the effort as flawed, nor have I come across any written critiques anywhere. I find the report to be transparent, well sourced, and forthright about methodology and the limitations of their methods. Some of these are based on complex calculations with wide margin for error. But even taken as back-of-the-envelope math (and it’s far more sophisticated than that), they lay out the scale of these impacts and define the bar if you want to put forth some other innovations as having had greater impact.

Among their findings:

  • Globally, permanent savings in carbon dioxide emissions (arising from reduced fuel use of 9,823 million litres of fuel) since 1996 have been about 26,221 million kg, with the additional amount of soil carbon sequestered since 1996 has been equivalent to 227,208 million kg of carbon dioxide that has not been released into the global atmosphere.
  • In the US the combined numbers for corn and soy are a savings of 2.8 billion litres of fuel from 1996-2015 and 72 billion kg of carbon emission sequestered or saved in reduced fuel burning.
  • In South America the numbers are even more dramatic. The combined fuel savings has been 5.8 billion litres of fuel and the combined carbon savings 166 billion kg.To put some of these numbers in perspective, they looked the carbon savings from 2015, the last year they had data from and found it the fuel savings “was the equivalent of removing 1.25 million cars from the road for a year and the additional soil carbon sequestration gains (23,900 million kg carbon dioxide) were equivalent to removing 10.62 million cars from the roads. In total, biotech crop-related carbon dioxide emission savings in 2015 were equal to the removal from the roads of 11.88 million cars, equal to 41% of all registered cars in the UK.’
  • Since 1996, the use of pesticides on the GE crop area was reduced by 618.7 million kg of active ingredient (8.1% reduction), and the environmental impact associated with herbicide and insecticide use on these crops, as measured by the Environmental Impact Quotient (EIQ) indicator, fell by 18.6%.  (Let me note that EIQ is a very rough and potentially problematic measure of environmental impacts, especially for herbicides, but also across so many variables on a gigantic dataset. At best it should be taken as a sign that across a range of measures, on balance toxicity fell. That doesn’t mean that toxicity didn’t rise on some measures in troubling ways and was cancelled out by other large improvements on what might be less salient variables. Take it with a grain of salt. I’ll share some more granular measures by weed scientist Andrew Kniss a little further down.)
  • In US cotton they find the Bt trait resulted in in an annual saving in the volume of insecticide ai use of 63.5% in 2015 (2.5 million kg) and the annual field EIQ load on the US cotton crop also fell by 27.5% in 2015 (equal to 53 million field EIQ/ha units). Since 1996, the cumulative decrease in insecticide ai use has been 24.9% (19.5 million kg), and the cumulative reduction in the field EIQ load has been 19.6%
  • In Bt corn, globally, they find a 53% (87 million kg) cumulative reduction in active ingredient and a reduction of 7.8 million kg for 2015 alone, amounting an 84% reduction for that year.
Bt adoption and insecticide reduction
The reduction in organophosphates, some of the nastiest insecticides is even more dramatic than the general trend.
That reduction registers in air quality samples.

Farmer income

In the interest of space, we’ll just look at the example of Argentina, a non-wealthy nation that bounces in and out of official “emerging market status”. From a development perspective, increasing farm incomes there is a big deal.

In Argentina, Brookes and Barfoot found savings from reduced expenditure on herbicides, fewer spray runs and machinery use have been in the range of $24-$30/ha (hectare), although since 2008, savings fell back to $16-$26/ha because of the significant increase in the price of glyphosate relative to other herbicides in 2008-09 and additional expenditure on complementary herbicide use to address weed resistance (to glyphosate) issues. Net income gains have been in the range of $21-$29/ha up to 2007 and $14-$24/ha since 2008. The net income gain from use of the Roundup Ready technology at a national level was $448 million in 2015. Since 1996, the cumulative benefit (in nominal terms) has been $6 billion.

An interesting wrinkle is that part of the gains for Argentine farmers is that Roundup Ready soybeans have allowed many of them to grow soy as a second crop after wheat harvest. The time freed up by the reduction in tillage practices allows for that second crop. Nearly 20% of the Argentine soybean crop came from wheat farmers supplementing their annual income in 2015, up from 8% in 1996. The represented a $484 million boost to national farm income in 2015 and $11 billion cumulatively since 1996.

What does other research show?

I want to look at two other areas before wrapping up. The first is sorting out the complicated picture on the impact of Roundup Ready and other herbicide-tolerant crops on environmental impacts. Then we’ll take a look at Bt cotton in India, Pakistan, and China.

Environmental Impacts of RoundUp Ready Crops

The researcher who has looked at the environmental questions most vexing the public debate is Andrew Kniss, a professor of weed science at the University of Wyoming. In 2017 he published “Long-term trends in the intensity and relative toxicity of herbicide use.” and Genetically Engineered Herbicide-Resistant Crops and Herbicide-Resistant Weed Evolution in the United States earlier this year.

The 2017 paper attempts to suss out the question of what has happened to herbicide use on major crops over the last two decades: Has use increased or decreased, have environmental impacts increased or decreased, and what role the RoundUp Ready traits have had on those changes? In a blog post on the publication of the paper, Kniss summarized his findings.

First of all, I found strong evidence that herbicide use has indeed increased in GMO crops (corn, soybean, and cotton), much as the critics have suggested. However, I also found that herbicide use has increased even faster in the non-GMO crops rice and wheat. This suggests that there is an overall trend for increasing herbicide use in all crops, irrespective of whether GMO varieties are available. It is even plausible, based on these data, that GMO crops have slowed the increase in herbicide use (though it is impossible to say for sure).

Another interesting finding from this analysis is that the trends in relative herbicide toxicity are different depending on whether you look at acute or chronic toxicity. Acute toxicity is what most people think of when they hear the word “toxic.” Acute toxicity describes how much of a chemical would be required to cause problems in a one-time exposure. Think spilling onto your clothes, or accidentally drinking the herbicide. But for pesticide applicators, the chronic toxicity of a herbicide is arguably more relevant, since they’re interacting with these chemicals on a regular basis for many years of their lives. It is rare for an applicator to accidentally ingest an acutely toxic dose; but much lower doses are required to cause chronic effects, as long as the exposure is repeated enough times. As a pesticide applicator myself, I was particularly interested in the chronic toxicity hazard results.

Of the three GMO crops in the analysis, the chronic toxicity hazard associated with herbicides has actually increased in corn and cotton, but decreased in soybean over the last 25 years. But in all three crops, few of the changes in herbicide use that caused chronic toxicity to change are directly attributable to the GMO traits. In the final year of corn herbicide use data (2014), just two herbicides (atrazine and mesotrione) made up 88% of the total chronic toxicity hazard. In cotton, just one herbicide (diuron) made up 88% of the total chronic toxicity hazard. Use of these herbicides aren’t tied to adoption of GMO crops; these herbicides were used before GMOs, and have continued to be used after GMO adoption.

Even though glyphosate use has increased greatly over the last 25 years, my analysis suggests the relative contribution of glyphosate to the chronic toxicity hazard has remained relatively low. Glyphosate has a very low chronic toxicity compared to most other herbicides. In corn and cotton, the chronic toxicity hazard increased over the last 25 years, but glyphosate contributed less than 4% to the chronic toxicity hazard in the final year of the data set. Similar results were observed in soybean, where glyphosate accounted for 43% of all herbicide treatments in 2015, but glyphosate made up less than 1% of the chronic toxicity hazard.

Another interesting finding in this paper is that most of the major reductions in toxicity hazard were unrelated to the adoption of GMO crops. Where toxicity was reduced, it was mostly due to EPA removing the most toxic herbicides from commercial use. In particular, registration cancellations for cyanazine, alachlor, and molinate had major impacts on the toxicity hazard quotients in the analysis .

The short version: Yes, herbicide use increased as a general trend, but the increase was higher in major non-GE crops like wheat and rice than it was in corn and soybeans. In terms of toxicity, the substitution of glyphosate for other herbicides significantly lowered the toxicity profile of herbicide use in the US, even as the amount of active ingredient increased. That looks like this in corn – total pounds, down slightly, toxicity way down:

Chart by Andrew Kniss

And like this in soybeans – pounds per acre up, toxicity down, though ticking up as glyphosate resistant pigweed became a problem in soybean production:

Chart by Andrew Kniss
The changes in detected herbicides are less dramatic than those for insecticides, but if you read that shift from green (other herbicides) to orange (glyphosate) you can see a qualitative shift as well as older, nastier herbicides dropped out of use.

And to return to a point raised earlier — one that bears repeating for our friends who haven’t internalized it yet — those reductions in insecticide use and herbicide toxicity are happening on nearly 90 million acres of corn and 76 million acres of soybeans in the US.

What about “superweeds”?

Before we get to Kniss’ paper, let me humbly recommend the primer on “superweeds” I did a few years back.

The methods and the results of the 2018 paper are laid out very clearly in the abstract of the paper:

Here, I analyze data from the International Survey of Herbicide Resistant Weeds and the USDA and demonstrate that adoption of GE corn varieties did not reduce herbicide diversity, and therefore likely did not increase selection pressure for herbicide resistant weeds in that crop.

Adoption of GE herbicide-resistant varieties substantially reduced herbicide diversity in cotton and soybean. Increased glyphosate use in cotton and soybean largely displaced herbicides that are more likely to select for herbicide-resistant weeds, which at least partially mitigated the impact of reduced herbicide diversity.

The overall rate of newly confirmed herbicide resistant weed species to all herbicide sites of action (SOAs) has slowed in the United States since 2005. Although the number of glyphosate-resistant weeds has increased since 1998, the evolution of new glyphosate-resistant weed species as a function of area sprayed has remained relatively low compared with several other commonly used herbicide SOAs.

The rate of weeds developing resistance to herbicides has slowed since 2005. There are other herbicides that are more vulnerable to resistance developing in the weeds they are meant to kill than glyphosate. There is a plausible case to be made that wider use of glyphosate took pressure off those herbicides and contributed to this lower rate. It might also be the case that the overall pressure of herbicide resistant weeds started hitting an economic tipping point for farmers so that it became unavoidable to start taking integrated pest management more seriously in weed control.

Either way, the data cuts against the popular narrative of herbicide-resistant weeds as an accelerating problem. Now, resistance in palmer amaranth (pigweed) is an accelerating problem – for interesting reasons. We’ll talk about that shortly.

Biotech Crops in India, China, Pakistan and Argentina

Despite the myth that the adoption of Bt cotton in India has led to a spate of farmer suicides, the story of Bt cotton in India has been one of robust success. In 2015, 25 million acres of Bt cotton were planted in India, 95% of total cotton plantings.

Let’s build this from the ground up, starting with pesticide poisonings in the region.

The reduction in exposure to dangerous pesticides is a much, much bigger deal in developing countries like China, Pakistan, and India. Pesticides and their use are poorly regulated. Unlike the US where pesticides are usually applied by tractor, often with a closed cab and with all the requisite protections, smallholder farmers apply pesticides on foot with backpack sprayers, usually with no protective gear. In the US, pesticide poisoning among applicators is very rare. In places like India, it’s far too common.

Bt cotton was adopted early in China. A 2002 study of the first five years found that in the first two years the rate of farmer-reported pesticide poisoning was reduced three to four fold among Bt adopters compared with non-adopters. More generally, they found that 4 million smallholders were able to increase yield per hectare, reduce pesticide costs and time spent spraying dangerous pesticides, while significantly raising incomes.

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A 2013 study found a significant reduction of pesticide poisonings among cotton farmers in Pakistan following the adoption of the Bt trait. The researchers conducted a survey of 352 cotton farmers, of which 248 were Bt adopters and 104 were non-adopters. “Farmers were asked about acute health problems that they had faced in connection with pesticide sprays in cotton during the last growing season. In particular, they were asked about the frequency and type of pesticide-related poisonings, such as skin and eye irritation, breathing problems, stomach pain, nausea, faintness, vomiting, and other symptoms.” The results, illustrated in the accompanying chart, found that the percentage of Bt farmers experiencing zero or just one incidence of pesticide poisoning were significantly higher than non-Bt farmers, while the percentage of non-Bt farmers experiencing three, four, five, or even six incidents was significantly higher than for Bt farmers. Some non-Bt farmers had as many as seven incidents, but no Bt farmers did.

A 2011 study of cotton farmers in India found Bt cotton “reduced pesticide applications by 50%, with the largest reductions of 70% occurring in the most toxic types of chemicals”. In terms of poisonings, they found “Bt cotton helps to avoid at least 2.4 million cases of pesticide poisoning in Indian farmers each year, saving US $14 million in annual health costs.” More generous estimates put the reduction in the incidence of pesticide poisoning as high as 9 million. Reductions were low in the early years of adoption but grew significantly after 2005. As you can see in the chart, the difference in the incidence of poisonings among Indian Bt and non-Bt cotton farmers is even more dramatic than in Pakistan.

What have been the other impacts?

In China, researchers looking at 15 years of data on cotton production saw a substantial decrease in pesticide use compared to non-Bt cotton. The decrease amounted to a saving of $105/hectare, or 50% of the pesticide use in 1996, the final year before the adoption of Bt cotton. Similarly, the adoption of Bt cotton led to a 17.25% reduction in labor compared to 1996.

One of the interesting things they found was that insecticide use continued to decrease steadily through the 15-year period. Rather than the uptick predicted by resistance developing in insect pests, pest populations were reduced to such a degree that they presented less of threat over time.

With Bt cotton adoption, Chinese farmers saved 4.12 billion yuan ($655 million) on pesticide use and 8.70 billion yuan ($1.4 billion) on labor use. Researchers calculated the total economic benefit that Bt cotton generated to be more than 33 billion yuan ($5.2 billion) over the 15 years.



In Pakistan, researchers found Bt cotton associated with 20% higher yields despite lower insecticide applications.

Using a farm survey and choice experiment of Pakistani cotton farmers, a 2013 study took a stab at putting a dollar value on the health and environmental improvement associated with Bt cotton. Researchers found that farmers valued those effects at $79 per acre, with half attributable to health and the other half to environmental improvements. Combined with the explicitly economic average gains of $204 an acre measured previously resulted in aggregate benefits of $283 per acre, or $1.8 billion for the total Bt cotton area in Pakistan.

A 2014 study quantifying the economic impact of greater energy efficiency and lower environmental pesticide impacts in Pakistan found Bt cotton 37% more environmentally friendly on those combined measures than non-Bt cotton. The researcher calculated the economic value of that improvement at $320 million.

In India, researchers observed a 24% increase in yield per acre for smallholder Bt cotton farmers due to reduced pest damage and a 50% gain in cotton profit among smallholders between 2002 and 2008. They further observed the gain in profits translated into 18% higher consumption expenditures, a common measure of household living standard, during the period 2006–2008. In a 2013 study, researchers found that increased income cut food insecurity by 15–20%, while significantly improving calorie consumption and dietary quality.

South Africa

In South Africa, the results of a 2004 study on farm income and inequality were particularly stark. “Bt growers had significant benefits compared to growers of non-Bt cotton in terms of gross margin over the three seasons. All other things being equal, Bt growers had a increase in gross margin of SA Rand 562/ha over growers of non-Bt. This is a significant sum. Assuming a typical daily wage of SAR 10/day in South Africa this equates to almost 2 months paid work. Of added interest is the finding that those with the smaller holdings appeared to benefit proportionately more from the technology (in terms of higher gross margins) than those with larger holdings.” The result of proportionately greater returns for smallholder farms brought down inequality significantly among Bt farmers and the benefits more evenly distributed among that group.

That paper also observed decreased bollworm insecticide use among Bt farmers.

In what might be the academic paper with my favorite name – ”Genetically Modified Maize: Less Drudgery for Her, More Maize for Him? Evidence from Smallholder Maize Farmers in South Africa” – in 2016 researchers looked at survey data collected in the Hlabisa district in KZN over a period of eight cropping seasons stretching from 2001 to 2010 to produce a set of gender-specific questions which were used in small group discussion in 2013 with women and men farmers in the Hlabisa and Simdlangentsha regions. They wanted to assess what those farmers valued in both herbicide-tolerant maize and stacked-trait maize with both herbicide tolerance and Bt insect resistance. What they found was an emphasis on the labor savings among women and yield gains among men. “Women farmers value the labor-saving benefit of HT maize alongside the stacked varieties which offer both insect control and labor saving. Higher yields are the main reason behind male adoption, while female farmers tend to favor other aspects like taste, quality, and the ease of farming herbicide-tolerant (HT) crops. Women farmers (and also children) saved significant time because less weeding is required, an activity that has traditionally been the responsibility of female farmers.”

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Wrapping up: How do biotech commodity crops fit in the system?

There is one major meta-analysis of the impacts of Roundup Ready and Bt crops that I didn’t include in tallying up the achievements of these traits. I bring it up now because, while I don’t think its a strong piece of research in measuring the impacts of the two main biotech traits, it is illuminating in looking at one of the more sophisticated objections to the way genetic engineering has been applied in agriculture thus far.

In the 2013 paper, “A Meta-Analysis of the Impacts of Genetically Modified Crops” Wilhelm Klümper and Matin Qaim looked at 147 studies of GE soybeans, maize, and cotton. The data from the papers was combined and collated to calculate global effects. The impacts they report were astounding:

On average, GE technology adoption has reduced chemical pesticide use by 37%, increased crop yields by 22%, and increased farmer profits by 68%. Yield gains and pesticide reductions are larger for insect-resistant crops than for herbicide-tolerant crops. Yield and profit gains are higher in developing countries than in developed countries.

If those numbers sound too good to be true, they should. In an astute critique of the paper, biotech critic Jack Heinemann, professor of molecular biology and genetics at the University of Canterbury in New Zealand, lays out numerous statistical and methodological problems with the paper, pointing out:

“At best, taking the meta-analysis at uncritical face value, it presents a correlation between GE crops and some measured benefits… it fails to differentiate between, on the one hand, differences in farmer income, ability to irrigate, and access to support—and importantly access to elite germplasm—and, on the other hand, the contribution of the GE trait. In other words, the meta-analysis confuses correlation with causation.”

I think that’s correct. I’ve seen these results touted uncritically far too often by people who should know better – including myself prior to reading Heinemann’s post. At best, what this meta-analysis shows is a correlation between GE adoption and major improvements in pesticide use, yields, and farm profits, but those improvements are bound up with a suite of technologies that biotech crops are often bundled with.

However, Heinemann’s point undermines the critique of biotech in agriculture that I alluded to. The more grounded, more sophisticated critics of biotech in agriculture will often say that while the benefits of the technology can be narrowly demonstrated on measures like yield or decreased insecticide use, their objection is that these traits and commodity crops are part of a system that is environmentally harmful and disadvantages farmers in favor of the major seed and input companies. But what we are seeing the Qaim meta-analysis and Heinemann’s reframing, is that the suite of technologies that biotech traits come bundled with, elite germplasm (improved seed), irrigation, synthetic fertilizer, synthetic pesticides, etc work together to reduce pesticide impacts while improving yields and farm income. That “system” delivers better results than what it is replacing.

Nor have we seen evidence of what some critics suggest, biotech lubricates the system and discourages more holistic, thoroughgoing solutions to problems. We have two very good natural experiments on that front. One of the first biotech crops to hit the market in mid-nineties was a Bt potato. The Colorado Potato Beetle is a major pest for potato growers and the Bt potato could have reduced insecticide use quite a bit in the production of America’s favorite vegetable. Anti-GMO environmental groups successfully petitioned McDonald’s to reject Bt potatoes. That collapsed the market for the seeds. In the intervening three decades, I’ve seen no evidence that production potato farmers went back to the drawing board to develop more holistic methods of insect control than they were using before. In terms of IPM, in 2016 the Southern Idaho Potato Cooperative contract included new language mandating a minimum of two years of alternate crops between potatoes. If that’s the revolution in sustainable potato production anti-GMO groups were aiming to pressure farmers into, mission accomplished. That’s a million acres in the US alone where we could have drastically reduced insecticide use, but we didn’t because of the objections of a particular strain of “environmentalists”.

Likewise, the wheat growers trade group lobbied against the commercialization of Roundup Ready wheat around 2004 and Monsanto dropped their wheat program in 2005. Because wheat figures so prominently in products like bread and pasta, they decided it wasn’t worth the headache of potential boycotts or disruptions to export markets. To my knowledge, wheat farmers continued controlling weeds with the same combination of herbicides and tillage they’d been using before. In the US alone that’s 50 million acres where we’ve already foregone the benefits of reduced tillage and improved an improved profile for herbicide use. Instead, as we saw in the Kniss paper, herbicide use in wheat increased faster than in corn and soybeans.

To be sure whatever system biotech commodity crops (or sets of overlapping systems) are embedded in is deeply flawed in many ways. The Dicamba debacle certainly revealed weaknesses in that system here in the United States. Monsanto had a supply of Dicamba resistant soybeans ready to sell, but the EPA delayed the release of a formulation of Dicamba approved for use in soybeans. Many farmers, facing severe yield loss from glyphosate resistant pig weed, went ahead bought the new seed and used other formulations of Dicamba, which was fine for them, but bad for their neighbors who didn’t have the new Dicamba resistant soybeans and saw some serious crop damage, as soybeans are normally very vulnerable to Dicamba. Then the EPA released the new formulation and that caused more problems. The system is far from perfect. No argument there.

The global, industrial food system faces huge challenges in terms of greenhouse gas emissions, soil degradation and erosion, nutrient runoff leading to eutrophication and acidification of oceans and lakes (think of the huge deadzone in the Gulf of Mexico or the massive algae blooms in the Great Lakes), water shortages, and deforestation. The Roundup Ready and Bt traits have made marginal improvements on all of these fronts across hundreds of million acres. Are they revolutionary? Maybe, maybe not, you’ll have to judge that for yourself. Perhaps not compared to what we can imagine or what might come next.
What might come next?

There are a number of innovations on the horizon that could turn out to be truly revolutionary for making agriculture significantly more sustainable. Plant meats that can scale to mass, global consumer markets and replacing vast quantities of animal protein sources would be world changing. Another area with room for vast improvement is the genetics of livestock in the developing world especially for cattle, as they grow to market weight much more slowly than in the US, meaning much greater methane emissions per pound of meat produced.

Bringing nitrogen fixation to grains would be revolutionary, especially for poor small holder farmers without access to synthetic nitrogen. Likewise efforts to make photosynthesis more efficient are likely to bear fruit sooner or later, seriously boosting yields. We aren’t far away from using AI and robotics to apply herbicides effectively, but in vanishingly small amounts, and that breakthrough could be easily eclipsed by weed control via RNA interference.

But a lot of what needs to be done is lots of improvements on the margins using technology we already have – more riparian buffer zones and pollinator habitat, greater use of cover crops, more precision irrigation, greater investment in anaerobic digesters in livestock and poultry production. And when I look back over the last three decades, that’s mostly what we’ve seen. Aside from reductions in tillage due to improvements in the hardware necessary for no-till and various minimum-tillage techniques, the only cluster of innovations that I think are anywhere in the running for being close to Roundup Ready and Bt traits in terms of making agriculture more sustainable are precision and variable-rate application technologies for seeding and the application of fertilizers and pesticides. While great, those are clearly improvements on the margin. The most exciting, variable rate fertilizer application doesn’t reduce the amount of fertilizer significantly. It just assures that it’s applied more efficiently. That’s great, but it’s hardly revolutionary.

I’m open to nominations, but I’m hard pressed to think of two innovations from the last three decades that have done more to improve the state of agriculture around the world.

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