Water quality plays an important role in the availability of pesticides and other chemical products applied to crops year after year. Knowing the chemical make-up of your water source allows for informed decisions about how to get the most out of crop inputs.
Tom Wolf, owner of Agrimetrix Research & Training based out of Saskatoon, Sask., is our resident expert on all things spraying, including how water quality could affect pesticide efficacy.
It’s one thing to identify the minerals and chemical make-up of spray water and to become aware of what potential problems it may cause, but it doesn’t do much good if you don’t have a solution for the problem at hand. In this episode of the Wheat School, Wolf will take us through what to look for in a water sample and if it is problematic, what you can do about it.
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Wolf explains that not all water quality tests are created equal. If you are planning on getting water tested, it’s best to do so through a lab, as at-home kits are generally designed to test water quality for home spas or home plumbing. When we are talking water quality for ag practices, we are looking to identify different properties and quantities.
Some of the most important things we are looking for according to Wolf are pH, bicarbonates and cations (positively charged ions: including sodium, calcium, potassium, magnesium and iron). The problem with having any of the above three qualities is that they can affect the structure, and therefore availability, of pesticides, making them less effective. This means you either have to use more product to achieve the same result, or you may have subpar results.
Hard water in particular can be a common problem and one that can reduce the efficacy of pesticides. This happens as the cations bind to the pesticide, changing the shape of them and as a result, it makes it more difficult for the pesticide to bind to the action site of the plant.
It’s not a one-size-fits-all problem as Wolf states, hard water problems only affect some products — the major ones being glyphosate and Liberty, along with some other Group 1 products. This is why it’s important to have an accurate water test to know exactly what it is you’re working with and formulate a plan accordingly.
Fortunately, if hard water is posing a problem, there are a couple different solutions to consider. Some will be easier, and cheaper, than others, depending on your location and specific circumstances.
First, Wolf says you could simply look for a different water source that has a more favourable chemical make up. This could include nearby town, county, or rural municipality water. Of course, this could be easier said than done and may create more of a hassle in logistics.
Alternatively, adding in a conditioner to water may be your best bet says Wolf. It’s a cost-effective way to correct the water quality issues that may be wasting product.
See the full conversation between Tom Wolf and RealAgriculture’s Brittany Warner in the video above. For more episode’s of Wheat School, click here for the full library.