By Andrew Campbell
When it comes to GPS technology, we all know the benefits of using it to find a restaurant nearby or to help us navigate traffic. But did you know farmers can use it too? And it’s not just to help them find a field, but it’s to help them find out exactly where they should be in a field. With the help of built-in GPS technology on tractors, a farmer can create a map that shows exactly where they have driven in a field and where they still need to go. That way, when they plant seeds, the seeder doesn’t overlap any parts of the field. Or, when pesticides need to be sprayed, every inch of the field gets sprayed only once, so no overlapping or over application of pesticides. With that in mind, we climb into a sprayer that uses this technology and uses it so well – that the steering wheel drives itself!
We are talking to Dave, a grain farmer in Ontario. He is growing corn, soybeans and winter wheat, and we’re in the soybean field today. We’re in a self-propelled sprayer and you’re not actually driving. How does that work?
This sprayer is outfitted with GPS and auto steer. It does give some comfort to the operator, but more importantly the auto steer prevents us from wandering as we go back and forth across the field. Using GPS and auto-steer prevents overlapping or missing areas in the field. We can be extremely precise with where we’re applying the product and anytime we can reduce overlaps, we’re not over-applying any chemical where we don’t need it.
When you say accurate, how accurate? I have my GPS for my car and sometimes it doesn’t guide me where I want it to.
This sprayer is accurate within about two to three inches. On a 90-foot sprayer pass, we might have a two to four inch overlap or gap. Which is much more accurate than what I can drive a 90 foot sprayer. The other thing that is really neat about the auto steer is that it knows where to go and it also records where it has applied spray. If I drive into an area that’s already been sprayed, the boom that’s applying the product shuts off automatically. So, if we’ve come to an angled headland, the boom will actually shut off individual sections across the 90 foot boom to prevent us from over-applying.
When you say product, you mean pesticide. Not everybody has a real warm and fuzzy feeling about pesticides. What is a pesticide?
Pesticide is any product that will control one of three things. Herbicides control plants (weeds), insecticides control bugs and fungicides control fungal diseases. Those are the three main pesticides used in agriculture and on our farm as needed.
We’re spraying a soybean field right now. What are we spraying and how does it work?
We are simply spraying a herbicide right now, that’s the one that controls weeds. That’s the pesticide that we most commonly use. Very rarely do we spray any insecticides. We use those extremely sparingly. We don’t want to kill any healthy bugs that are helping our crop. However, Weeds are a competitive plant in our soybean field and we don’t want them competing with our crop. If we don’t control weeds and they go to seed, then the problem increases and spreads to larger areas beyond where our own field is.
If you have a soybean plant growing beside a dandelion, what do you mean by competing between the two?
With different plants growing in the same area, it’s no different than if you have a garden and you have tomatoes growing and all of a sudden you have a large weed. It’s competing for sunlight, soil moisture, and nutrients. When you get a much larger weed it’s going to shade out many other plants around it. There are some weeds that we are challenged with here in Ontario. One in particular puts out 200-300 thousands seeds per plant. If we don’t control that, it can create tremendous issues.
Why don’t you go out with a hoe to control your weeds ?
Some mechanical control of weeds is okay, but it can also work up more seeds that can germinate and cause problems. But the biggest deterrent would be the labour. We would need a labour force of 100-200 people. It’s really just not feasible. The cost of food would go way up.
Are pesticides safe? Are they dangerous? If somebody’s eating soybeans, should they be worried?
I farm and live in the same area. I raised my kids right next door to all of our fields. Pesticides are safe and safety regulations are rigourous and constantly improving. The products we use pass extremely stringent testing in Canada. There are products that are used in other countries that we aren’t allowed to use here as they haven’t met the Canadian safety ratings.
When we talk about volumes of them, what we are spraying right now to kill weeds is very minimal. We put on 0.8 litres/ acres of product. If you look at a standard size water bottle, we put the equivalent of 1 ½ standard water bottles (750 mL/3 cups) of product on every acre. An acre is 43,560 square feet which is about the size of an American football field. Officially, it is 43,560 square feet, and a football field is 48,000 square feet.
So, we are applying the equivalent of 1 ½ water bottles of herbicide, along with 10 gallons of water per acre. There is no reason for us to use very large amounts of herbicide when all it takes is a small amount to get into the system of the weed to kill it. The volume of herbicide is very low and they are used at very safe levels. Further, at harvest time, we’re not allowed to have any measurable amount of residue from pesticides in the crop. Crops like soybeans are shipped to export markets like Asia and Europe and there are very strict rules around that.
These soybean plants are still small and it will be a while before you harvest. Could you spray the day before you harvest?
No. There are rules around minimum time allowances between spraying and harvest. I need to record when I’m applying this product and eventually record my harvest date. I need to have a certain window of time from when I was last in the field applying product. Every farmer has to pay close attention to that and keep records.
How many times do you spray a crop? Do you spray it every week?
For our corn and soybean crops, usually a single pass with a herbicide is all that is needed during the entire growing season. For soybeans, we will come in and make sure the field is clear of weeds prior to seeding. We will do an initial pass to get rid of weeds before we plant the soybeans and this will be our last pass through the soybeans for spraying any weed control spray. We will monitor the crop and the only other potential pass we might make is if we get a really big infestation of a fungal leaf disease. Then we will put some fungicide on, but we only spray that if we need to.