Heritage Radio Show Notes


Tillage Stats [PDF]

Farmers applied tillage practices on 278.8 million acres in 2012, including no till on 96.5 million acres, conservation tillage on 76.6 million acres, and conventional tillage on 105.7 million acres. Across the country, 278,290 farms used no till. In no-till farming, the farmer plants the crop directly into the vegetative cover or crop residue of the previous crop. Farms of all sizes reported having acreage they did not till, but more than half the no-till acres (54.4 million) were on farms that applied the practice on a thousand or more acres.

In addition, 195,738 farms used other conservation tillage practices (excluding no till) on 76.6 million acres. Conservation tillage includes some tillage, but leaves a minimum of 30 percent of the soil surface covered by the previous crop’s residue following the planting operation. Over half the acreage (41.6 million acres) was on farms that practiced conservation tillage on a thousand or more acres.

Cover Crops

Iowa farmers planted more than 353,000 acres of cover crops with financial assistance from state and federal conservation programs in the fall of 2016 – nearly 18 percent more than the previous year. Based on statewide surveys and aerial imagery completed by conservation groups this spring, agriculture leaders estimate Iowa farmers planted at least 600,000 cover crop acres last fall. The new cover crop mark represents the second consecutive year with an increase of more than 60,000 acres.

Glyphosate and Cancer: What does the data say?

Additionally, in the case-control studies I read, a very small minority of NHL cases were actually exposed to glyphosate. For example, only 97 people (3.8% of the study population) had been exposed to glyphosate in the DeRoos (2003) study. Similarly, only 47 people (2.4% of the study population) had been exposed to glyphosate in the Eriksson (2008) study. These are very small numbers. To look at it another way, only about 3% of the NHL cases in most of the case-control studies had actually been exposed to glyphosate. So even if glyphosate does increase the risk, it certainly is not a major contributor to NHL cases in the general population.

But case-control studies aren’t the only types of studies that have been used to investigate the link between glyphosate and cancer. DeRoos et al. conducted a follow-up to their 2003 study using a different, and arguably better methodology. Cohort studies follow a group of people during some portion (or all, depending on the study) of their lives, and track many risk factors and health outcomes. DeRoos et al. (2005) looked at a group of 54,315 agricultural workers. Once again they used two different models in their analysis, but the results of this study were contrary to what was observed in the case-control studies.

REUTERS: Cancer agency left in the dark over glyphosate evidence

Previously unreported court documents reviewed by Reuters from an ongoing U.S. legal case against Monsanto show that Blair knew the unpublished research found no evidence of a link between glyphosate and cancer. In a sworn deposition given in March this year in connection with the case, Blair also said the data would have altered IARC’s analysis. He said it would have made it less likely that glyphosate would meet the agency’s criteria for being classed as “probably carcinogenic.”

. . . The unpublished research came from the Agricultural Health Study, a large and significant study, led by scientists at the U.S. National Cancer Institute, of agricultural workers and their families in the United States. Asked by Monsanto lawyers in March whether the unpublished data showed “no evidence of an association” between exposure to glyphosate and non-Hodgkin lymphoma, Blair replied: “Correct.”

Asked in the same deposition whether IARC’s review of glyphosate would have been different if the missing data had been included, Blair again said: “Correct.” Lawyers had put to him that the addition of the missing data would have “driven the meta-relative risk downward,” and Blair agreed.

Our Wiki research collections can be found here. I really encourage people to compare and contrast what the research literature for a safe,relatively benign pesticide like glyphosate looks like in comparison with a pesticide that presents legitimate and significant risks like chloripyrifos. You can dismiss the research on glyphosate as possibly influenced in part by Monsanto (although there isn’t any evidence that they cooked the research, only that they took steps to see that positive research was published), but then you have to explain why Dow, a much larger company with greater stake in the chemical input business hasn’t been able to generate similar impact on research results.

On So-Called “Superweeds”

Note that resistant issues are much greater for ALS Inhibitors, Triazines, and ACCase Inhibitors than for Glycines, despite the more widespread use of Glycines. The resistance problems for herbicides with those modes of action would be much greater is glyphosate hadn’t taken the pressure off of their use.

As you can see, herbicide resistant weeds are hardly unique to glyphosate and considering the fact that glyphosate is planted on a massive amount of acres compared to other herbicides, the low rate is all the more impressive and it seems to be leveling off as farmers have addressed the potential for problems. In fact the move to glyphosate has actually improved the situation with herbicide resistant weeds by decreasing the use of atrazine which was the most popular herbicide before RR crops came along.

Why was atrazine so popular? Because corn is naturally resistant to atrazine. Nature had made it’s own Atrazine Ready crop. So GE crops aren’t the only herbicide resistant crops. In fact, BASF has a seed/herbicide program called the Clearfield system which pairs non-GE rice, wheat, and sunflowers with the herbicide imazethapyr, ALS inhibitor. Clearfield crops are widely used and have their own resistant weed problems.

Here’s the rub, the crux, the one thing almost no one seems to realize in all this: If imazethapyr was a more effective herbicide than glyphosate, then imazethapyr would be over-relied upon on a mass scale and non-GE Clearfield crops would be the elephant in the room and not RoundUp Ready crops. If that were the case, I’m not sure that we’d be having this conversation outside of the ag press and the email alerts of a handful of environmental groups. But, glyphosate is a too good to be true combination of environmentally benign and devastatingly effective on weeds herbicide. It really is too effective for it’s own good and farmers will tell you that. The problem of glyphosate resistant weeds is real, but it needs to be understood in the context of other herbicides. It should also be recognized that farmers have already started to adjust and as you can see in the chart, the number of NEW weeds becoming resistant slowed down beginning in 2010, but you can see an uptick in this last year. But take GE herbicide resistant crops out of the picture and it’s not clear that the resistance issue would see any improvement, nor is it clear at all that we would have been better without them.

On the “Chemical Hangover”:

As we’ll see, the pesticides in use have become less toxic and more degradable over time. The second thing to keep in mind is that the population of the US in 1980 was 230 million, in 2008 it was 304 million. Yields have gone up dramatically. So, while use per acre has only modestly decreased since 1981, it has gone down dramatically both per capita and a per unit produced, while at the toxicity and biodegradability have improved. That’s not to say that use per acre isn’t important, but we should keep aware of other ways of assessing what’s going on to get a fuller sense of what has actually happened.

The chemical hangover of the post-war era

The disconnect mostly comes from the chemical hangover from the unfortunate excesses of industry during the 1950s, 60s and into the 1970s. DDT, PCB’s, a raft of dangerous food colorings and additives pulled from the market, Love Canal and similar incidents left people with the unshakeable feeling that everything causes cancer and technological progress might be more trouble than it’s worth. People have a much better handle on that dismal chapter of history than they have on the reforms and innovation that followed. With creation of the Environmental Protection Agency and the passage of the Clean Air and Water Acts, regulation has become much tighter. Meanwhile, scientists began working in earnest to create pesticides that were more effective, while making less impacts where they weren’t supposed to. Environmental watchdog groups have worked hard to make sure that they do.

There are other reasons for the disconnect. There is a notable lack of incentives for both environmental groups and agri-chemical companies to trumpet the progress that’s been made in lowering the toxicity and reducing the collateral damage of pesticides. Another source of disconnect is the way organic farming has been marketed or perceived, falsely, as pesticide free. Pesticides as an environmental impact are often played up by organic advocates and advertisers as a way of highlighting the benefits of organic agriculture.

All of these threads have come together to create a widespread lack of understanding that modern pesticides are much safer and less toxic than earlier generation chemicals. Many pesticides have been banned in recent decades and those that have been approved are much more targeted in the way that they work. Following the uproar over DDT, scientists have made degradibility a central priority, so today’s pesticides are far less persistent in the environment.

Environmental Impacts of GE Crops

The environmental impacts of Bt and RoundUp Ready crops have been unequivocally good relative to the most likely counter-scenario.Some stats from Brookes and Barfoot’s “GM crops: global socio-economic and environmental impacts 1996- 2014” (2016) [PDF]

  • Since 1996, the use of pesticides on the GE crop area was reduced by 640,883 tons of active ingredient (8.2% reduction), and the environmental impact associated with herbicide and insecticide use on these crops, as measured by the EIQ indicator, fell by 18.5%.
  • Bt cotton has contributed a 43% reduction in the total volume of active ingredient used on GE crops (-249.1 million kg active ingredient, equivalent to a 27.9% reduction in insecticide use on the Bt cotton area) and a 36% reduction in the total field EIQ indicator measure associated with GE crop use (1996-2014) due to the significant reduction in insecticide use that the technology has facilitated, in what has traditionally been an intensive user of insecticides. Similarly, the use of Bt technology in maize has led to important reductions in insecticide use (79.7 million kg of active ingredient), with associated environmental benefits.
  • The volume of herbicides used in GE maize crops also decreased by 235,000 tons (1996-2014), an 8.4% reduction, whilst the overall environmental impact associated with herbicide use on these crops decreased by a significantly larger 12.6%. This highlights the switch in herbicides used with most GE herbicide tolerant (HT) crops to active ingredients with a more environmentally benign profile than the ones generally used on conventional crops.
  • Important environmental gains have also arisen in the soybean and canola sectors. In the soybean sector, whilst herbicide use increased by 5.5 million kg (1996-2014), the associated environmental impact of herbicide use on this crop area decreased (improved) by 14.1%, due to a switch to more environmentally benign herbicides. In the canola sector, farmers reduced herbicide use by 21.8 million kg (a 17.2% reduction) and the associated environmental impact of herbicide use on this crop area fell by 29.3% (due to a switch to more environmentally benign herbicides).

Impacts on Greenhouse Gas Emissions

  • Reduced fuel use from less frequent herbicide or insecticide applications and a reduction in the energy use in soil cultivation. The fuel savings associated with making fewer spray runs (relative to conventional crops) and the switch to conservation, reduced and no-till farming systems, have resulted in permanent savings in carbon dioxide emissions. In 2014, this amounted to about 2641 tons (arising from reduced fuel use of 898 million litres). Over the period 1996 to 2014 the cumulative permanent reduction in fuel use is estimated at 24,000 tons of carbon dioxide (arising from reduced fuel use of 8,124 million litres);
  • The use of ‘no-till’ and ‘reduced-till’ farming systems. These production systems have increased significantly with the adoption of RoundUp Ready crops because the RoundUp Ready technology has improved farmers’ ability to control competing weeds, reducing the need to rely on soil cultivation and seed-bed preparation as means to getting good levels of weed control. As a result, tractor fuel use for tillage is reduced, soil quality is enhanced and levels of soil erosion cut. In turn more carbon remains in the soil and this leads to lower GHG emissions. Based on savings arising from the rapid adoption of no till/reduced tillage farming systems in North and South America, an extra 5,449 million kg of soil carbon is estimated to have been sequestered in 2014 (equivalent to 19,998 million kg of carbon dioxide that has not been released into the global atmosphere). Cumulatively, the amount of carbon sequestered is likely to be higher due to year-on- year benefits to soil quality; however, it is equally likely that the total cumulative soil sequestration gains are not the sum of each individual year’s estimated saving because only a proportion of the crop area will have remained in permanent no-till and reduced tillage. It is not possible to confidently estimate cumulative soil sequestration gains that take into account reversions to conventional tillage because of a lack of data. Consequently, our estimate of 186,945 million kg of carbon dioxide not released into the atmosphere for the cumulative period 1996-2014 should be treated with caution.Placing these carbon sequestration benefits within the context of the carbon emissions from cars,
  • In 2014, the permanent carbon dioxide savings from reduced fuel use were the equivalent of removing 1.07 million cars from the road;
  • The additional probable soil carbon sequestration gains in 2014 were equivalent to removing 8.89 million cars from the roads;
  • In total, in 2014, the combined GE crop-related carbon dioxide emission savings from reduced fuel use and additional soil carbon sequestration were equal to the removal from the roads of 9.95 million cars, equivalent to 34% of all registered cars in the UK;
  • It is not possible to confidently estimate the probable soil carbon sequestration gains since 1996. If the entire GE HT crop in reduced or no tillage agriculture during the last twenty years had remained in permanent reduced/no tillage then this would have resulted in a carbon dioxide saving of 186,945 million kg, equivalent to taking 83 million cars off the road. This is, however, a maximum possibility and the actual levels of carbon dioxide reduction are likely to be lower.


Selected readings

The 10 Minor Realizations That Flipped My Thinking About GMOs
• GMOs: An Introduction
• On So-Called “Superweeds”
• Answering the 3 Most Common Internet Objections to GMOs
• About Those Industry Funded GMO Studies . . .
• 17 Questions about Glyphosate
• Glyphosate and Cancer: What does the data say?


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