As we have been seeding, we have also be conducting pre-seed burn-offs. This uses a herbicide that is sprayed to remove all undesirable plants from the field before seeding. Leaving a clean field for the crop to be established on with minimal competition.
Why do we spray?
Growing a crop faces a number of challenges. From germination, establishment right through to a successful harvest. The UN Food and Agriculture Organization estimates that 20-40% of the global crop is lost due to plant pests and diseases.
One of the main things impacting crop yield is competition from weeds, that take nutrients, sunlight, space and moisture away from the crop. Of the 250,000 known plant species, about 3% or 8,000 are weeds. Of those 200-250 have a significant impact on food production and supplies. Weeds are characterized by abundant seed production, rapid population establishment and seed dormancy. Some weed seed, under the correct soil conditions, can stay buried and survive for up to 40 years. In the United States each acre of cropland is estimated to have between 50-300 million buried weed seeds.
What do we use?
The product used can vary depending on crop, soil, crop rotation, current condition of the crop, and moisture. The product is only used as labeled for a specific purpose and at very specific amounts. It is not an expense (of both time and resources) taken haphazardly. The choice of what to spray, when and how much are carefully calculated, and measured out. Herbicides have different classifications and modes of action. Herbicide resistance is always a concern and is part of why crop rotations that support herbicide rotations on a field are important.
A sprayer is a precision instrument to ensure we have an exact application rate. Use of a GPS ensures we avoid overlap within the field. Wind conditions are monitored. We avoid spraying in winds greater than 20 km/hour, as we want to avoid drift into neighbouring fields (remember those maybe our fields!).
What is the risk?
Spraying is conducted so that the targeted plants absorb the product. Operators take precautions when using the products to ensure their safety. All spraying operators have taken a spray applicator course or been trained to handle chemicals appropriately.