Does Glyphosate Cause Cancer?

Glyphosate and cancer. This is something we are hearing so much about, seemingly all of the sudden, with major stories breaking in the last week. Just last Friday, a court case in California resulted in a $289 million dollar payment to a man named Dewayne Johnson, who claimed his years of using glyphosate (also known as Roundup) caused him to develop cancer. A few days before this story broke, glyphosate use was suspended by a judge in Brazil pending a government reevaluation of its toxicity.

What is going on here?

I am a farmer who uses glyphosate. My dad started using it decades ago, and it has absolutely been the single greatest invention in agricultural history. And it is unequivocally, fantastically safe. It is one of the lowest toxicity herbicides we use on our farm. It is less toxic than alcohol. Less toxic than caffeine. So what is all this about?

Why Do We Need It?

I am apart of a multi-generation family farm in southeast Saskatchewan, Canada. We grow canola, wheat, durum, peas, lentils, flax and soybeans, along with a few other crops. I farm with my sister, my mom and dad, my brother-in-law and my wife and two little boys. I love what I do.


In my part of the Canadian Prairies, we farm in some pretty dry conditions. Our average growing-season rainfall is about 9 inches, or 225 mm. Snow and fall rains provide us with another 4-5 inches. This is semi-arid agriculture, where the next rain really can provide the difference between profit and loss. So, we work very hard to use every drop of moisture we get. We have to. That means we cannot allow weeds to grow, and we must leave the soil undisturbed as much as possible – we do not want to till our land if we can at all avoid it.

What glyphosate allows us to do is to kill every weed in the field before the crop emerges. In the days before glyphosate, my grandfather had the very same goal – but he only had one way to do it. He had to work the land, over and over and over. The goal was to make it absolutely black. That was the only tool they had, and sadly, it was the direct cause of the great dust storms of the Dirty 30’s. Why would we ever want to go back to that?

Moreover, glyphosate allows us to control weeds in certain crops as they grow. Canola and soybeans are two crops I grow that are genetically engineered to be resistant to glyphosate. This means we can spray it over the crops, while they are young and struggle to compete with weeds, to keep them clean. We use different chemicals in other crops to accomplish the same thing, but none have the broad spectrum control that glyphosate has – and few of them are as cheap, or as safe.

The introduction of Roundup-Ready crops, including corn, soybean, canola, cotton and so on, has allowed for safe, simple, very cost-effective weed control.

Is It Safe?

This is the big question, and if you follow the news at all, I could certainly understand if you don’t feel it is safe. You may think it causes cancer, autism, and any number of diseases. That is what you’ll find on the Internet.

Here’s the experience of a farmer.

I use glyphosate hundreds of hours every year. I load and run our sprayers (along with farm employees and my family) over thousands and thousands of acres spraying glyphosate. My son rides in the sprayer with me sometimes. And I don’t worry at all about glyphosate being dangerous.


Here’s the thing about spraying a chemical like glyphosate. An acre of land is 43,560 square feet, which is a little smaller than an American football field. On that acre, 360 grams of glyphosate active ingredient is sprayed. Put another way: 2 cans of beer of glyphosate sprayed over an area almost the size of a football field. That’s .015 mL of beer on each square foot – and that includes the solution the glyphosate active ingredient is suspended in. That is an incredibly low concentration. A standard “drop” of water is .05 mL. That’s less than a third of a drop of water!

Sure, some chemicals are highly toxic in even very small doses. Glyphosate is not one of those chemicals. Its LD50, or the lethal dose for 50% of rats in testing, is 5,600 mg/kg. The LD50 for caffeine? 192 mg/kg. Don’t panic about your coffee though – that’s still very safe!

Does Glyphosate Cause Cancer?

While I have explained that an acute dose of glyphosate is safe, that doesn’t really answer the cancer question. That is something that would accrue over many years, and may have little to do with the aforementioned LD50. Has this been studied thoroughly enough to be sure glyphosate is indeed safe? And has it been studied by independent organizations and scientists?

John Giesy, a professor and research chair in environmental toxicology at the University of Saskatchewan, would argue that yes, glyphosate is safe. He has quite the resume, as a professor or honorary professor at six other universities and is the most cited author in the world in the combined fields of ecology and environmental sciences. In an article you can find here, when speaking about the subject of cancer, he had this to say:

“Certainly you wouldn’t wish it on anyone. But whether it’s caused by glyphosate, in my opinion, is highly unlikely.”

In 2015, the International Agency for Research on Cancer (IARC), a WHO agency, claimed that glyphosate was a  “probable carcinogen”. Glyphosate is hardly alone in this category, with such partners as high temperature frying, working as a hairdresser, red meat or shiftwork. Stuff that is actually carcinogenic on their list? Alcoholic beverages, sawdust and processed meat (to name a few). Yes, beer and hot dogs are considered more likely to cause cancer than glyphosate (source).

It was this IARC report that started all of this, and there are some real questions as to their methodology. In fact, according to the then- European Crop Protection Director, General Jean-Charles Bocquet,

“From the summary conclusions it appears that IARC has made its conclusions as a result of an incomplete data review that has omitted key evidence.” (source)

It was recently discovered that the IARC had removed findings from studies that concluded glyphosate was not a carcinogen before they published the final version. They also used the infamous, now retracted Seralini rat study in their analysis.

The fact is that numerous organizations conclude glyphosate is safe, including the UN’s Food and Agriculture Organization, the European Food Safety Administration, Health Canada, the German Risk Agency, and on and on. A massive study run on 89,000 farmers and their familes in Iowa and North Carolina since 1993 has failed to find any link between glyphosate and cancer. How much more evidence do we need?

I need glyphosate on my farm. It helps me be more sustainable, both environmentally and economically, it helps me protect my soil from erosion and build soil health, and it helps me sequester carbon, reducing greenhouse gas emissions. The fear over glyphosate is unfounded, and we need to slow down and have a real discussion about it. If you want to come to my farm and see how we use this contentious chemical, please let me know. My door is open for anyone who wants to have their questions answered.

Seeding 2015 in Pictures

For the last number of years, seeding has been a sprint to the finish. Difficult weather conditions, with constant rain in the forecast, pushed us to hammer the crop in as quickly as possible. This year has been a a very different – and welcome – experience. However, it has not been without its challenges, with cool May nights and rains causing real concerns.

We completed #plant15 on Saturday, May 23. It’s hard to believe it took that many weeks, considering the relatively relaxed atmosphere that it was, being that we actually started on April 23rd. We had a few breaks, including a 5-day rest before the final run. It rained last weekend, shutting us down just as we completed the flax. We started again on Wednesday with the soybeans and one last field of canola.

I think one of the best ways to tell you about seeding is to show it to you. So, what follows is a collection of photos from the seeding season.

Preparing to start seeding is always stressful.
Preparing to start seeding is always stressful.

Getting ready to go seeding is, as a previous blog stated, hell. There are endless jobs to do: cleaning, treating and organizing seed; checking and loading drills and air carts; finding and fixing the numerous problems that pop up every spring; hauling and marketing grain; and the non-stop job of managing cash flow. All of these things are all in preparation for the most  important job of the year: seeding. Dad rather accurately refers to this time as “Hell Week”.

The first couple of days of seeding tend to be slow - it takes awhile to get in the swing of things.
The first couple of days of seeding tend to be slow – it takes awhile to get in the swing of things.

We usually start seeding with peas. A large-seeded crop that does well in cool soils, peas are a flexible crop that work well early, especially since they are a shorter-season crop that can be combined early as well.

We have two drills: one is an old-style hoe drill, as shown above, with a fixed frame that each shank is directly attached to. Since the shanks are not independent of each other, depth control is pretty poor. The frame of the drill cannot follow the contours of the ground very well, so all shanks are essentially controlled as one. Our other drill, a SeedMaster, has independent depth control; meaning, each shank is hydraulically pressured against the ground to consistently follow the contours of the soil. For small seeded crops like canola and, to some degree, cereal crops like wheat and barley, this is a vital tool to ensure proper depth of each seed. For large seeded crops like peas and lentils, this is rather unnecessary, and we find the hoe drill works just fine. The advantage of the hoe drill is simplicity. They are cheap, easy to fix and handle all kinds of tough field conditions – but they do have their limitations. That is why we usually have our drills split up throughout seeding.

Spraying is an intense, fast-paced operation.
Once the drills get moving, burn-off begins. Spraying is an intense, fast-paced operation.

Once seeding really gets going, it is time to get the sprayer out and get some “burn-off” done. Burn-off, or pre-seed spraying, is a very important operation to do precisely. The wrong chemical on the wrong field could spell disaster, and it is important to try and stay a couple days ahead of the drills. Since we can seed upwards of 700-800 acres per day, that makes for some very long days in the sprayer. These machines are marvels of technology, with automatic boom height control, prescription-applied products, touchscreen controls and a variety of performance-enhancing features to make you more productive every day. They do, however, come with a steep sticker price!

It is critical to ensure burn-off is done properly. The best defense against weeds is to simply not have them at all; a well-timed burn-off with the right products at the right rate can mean the difference between a clean field and a dirty one, which can make all the difference in your farm’s ability to produce a profit. Chemistry is a surprisingly important aspect of farming today.

Treating seed is a difficult but vital component of seeding.
Treating seed is a tricky but vital component of seeding.

One aspect of farming that has seen significant change in the past few years is treating seed. Only a few short years ago, most of Dad’s crop went in the ground without seed treatment. That was due to a few factors: treating equipment was poor, the products were pretty weak, and there was a general belief among farmers that it was a waste of money. Today, seed treatment products are a vast improvement over their predecessors, with some of the best chemistries in agriculture going into them. Treating equipment is much more accessible, affordable, and accurate. With the massive investments that go into the ground during seeding, adding a treatment to protect the seeds is just good management. Although getting good coverage and proper application rates is still difficult, the end result of a protected seed is well worth it.

These little canola seedlings may have a long way to go - but every journey has a first step.
These little canola seedlings may have a long way to go – but every journey has a first step.

Seeing the first little seedlings push their way out of the ground is a wonderful feeling. It is at that moment that you know you’ve got a crop, that all your planning and hard work is finally starting to show for something. But, the reality is that there is a lot that can go wrong yet, and one disadvantage of our early start to seeding this year is the threat of frost. You see, it is quite common for us to get freezing nighttime temperatures well into May. Canola is very susceptible to freezes, as its growing point is exposed as soon as it cracks the ground. This canola crop emerged in early May.

Last weekend a system moved in, referred to as a “Colorado Low”, that clashed with a very warm weather system we had been experiencing. These two weather systems reacted violently together, with substantial rainfall and even snow falling east of here. We got some rain out of it, which was rather unwelcome; but the more concerning part was the cold nights to follow. As the skies cleared Monday evening, the temperature quickly dropped below freezing. In fact, for ten hours that night the temperature was below the freezing mark, and maxed out at -5.1 degrees Celsius. That is a very cold night for our little seedlings, and I was sure our early canola would be lost. Amazingly, all of it survived it just fine! I’m counting my blessings on that one; we don’t usually get that lucky.

As seeding wears on, the days tend to get longer and longer.
As seeding wears on, the days tend to get longer and longer.

It is about the halfway point of seeding that you really begin to feel it. The late nights, the early mornings, the constant planning and math that you have to do. The drive for perfection, or as close to it as you can get, pushes you to do everything as perfectly as you possibly can. But, as seeding drags on, it can be hard to keep the intensity up. That is precisely why a good rain delay is incredibly important.

Winter, Spring 2014-2015 237
Managing the logistics of seeding is not easy – you have to do everything you can to keep those drills moving. Loading is not all that dissimilar to a NASCAR pit stop.

Seeding isn’t all about tractors, drills and sprayers. Some of the most important jobs are keeping those machines moving. Our liquid fertilizer truck never stops moving all the way through seeding. Those two drills, on a typical canola or wheat field, burn through approximately 9,000-11,000 litres (2,400-2,900 US gallons) of liquid fertilizer per hour. Moreover, they are using up tonnes upon tonnes of seed, dry fertilizer and diesel fuel. The sprayer, tearing along at 175 acres per hour, uses thousands of litres of water each hour, and is often too far from home to drive back to load each time. Keeping up with all these demanding machines takes an incredible amount of planning and logistics. And, with all the wet weather we’ve been having, driving highway semi trucks up and down some of our back roads is no easy task.

Each field requires a lot of logistics to complete efficiently - even the final one.
Each field requires a lot of logistics to complete efficiently – even the final one.

The last field is always a fun one to start. The end is so close you can taste it, and you start to think about all the other jobs to start on when you’re done. But, that final field can often be a total nightmare. This particular field has been extremely wet for the past few years, and, just like in 2014 and 2012, it was our final field this year. Last year, it took 4 days to seed this 500 acre section; we can normally seed that in one day with just one of our drills. In 2012, both drills hammered away at this field for days, with numerous stucks and difficulties making it an infuriating experience. With eyes wide open as to how difficult this field can be, we headed down there with our SeedMaster.

As the other drill finished up the soybeans, we switched back to canola to get through this DSC_0141horribly cut-up field. Amazingly, we actually plowed through it with very few issues, and in a day and a half, it was completed. The finished map for the field was a bit of a mess (see insert at right), but that was kind of expected. It has been quite a few years since we seeded through many of the low spots down there.

Even though seeding is now “completed” there is still some seeding left to do, with previously inaccessible low spots now dry enough to seed. And, although seeding is definitely one of the busiest times of the year, there is a lot to do as we move into June, with in-crop weed spraying starting up very soon, drills to clean up and put away, grain to move and fields to scout to ensure no pests take away our hard-earned crop. Beyond that, initial preparations must begin for harvest, which will be early this year.

For now though, we will celebrate another crop in the ground and another successful planting season. Summer in Saskatchewan is a beautiful time, and we have to find time to enjoy it. After all, while we all love farming, we do need a break from it from time to time; and what better way to do that than a weekend at one of Saskatchewan’s fantastic lakes?