One thing that we don’t often talk about? Spraying. But the truth is, whether you’re applying natural products, water, fertilizer or synthetic materials such as pesticides or herbicides, spraying your crops fields is a reality for many farmers.
And when it comes time to spray your fields, it’s really important to calibrate your sprayer for optimal performance.
I’m partial to the 1/128th method for sprayer calibration. Sounds complicated, right? It’s actually really easy!
Why Is Sprayer Calibration Important?
First, why is sprayer calibration so important? The answer is pretty simple: You want to control the amount of product that you apply to the field.
Uneven application can lead to some areas receiving too little sprayed product, with others receiving more than intended amount.
To start your sprayer calibration, collect a long tape measure or measuring wheel. You’ll also need a couple of flags, as you need to mark your starting point as well as where you stop.
You’ll also need a standard tape measure to measure spray nozzles and a graduated measuring cup to measure how many ounces of sprayed material are being output. Other items you should have on hand include:
- Notebook and pen, or other way to take notes
(Quick tip—your phone can provide all of the last three items.)
First, you need to measure the distance between your nozzles. Why? Your spray chart uses this information to tell you how far you’ll need to drive. (See the video above for a spray chart you can use, or request one from your local extension.)
Once you’ve got your nozzle distance measured, use your flags to mark the distance prescribed by your spray chart.
Then, just drive that distance, timing yourself to determine exactly how long your tractor needs to get from one flag to the other. (You can do this a few times to get a more accurate average.) Note this time in your notebook or phone to use in the next step of your sprayer calibration.
Back to the Sprayer
Fill your tank with water. Once your sprayer’s pressure is where it’s supposed to be (this is set by the manufacturer), put the measuring cup beneath one of the spray nozzles. Then, let the nozzle spray water (while collecting the liquid in your cup) for the amount of time determined in the earlier step.
Note how much water you collected. Repeat this process for all of your nozzles, then average the numbers. (If any of your nozzles is significantly different than the others, replace it.)
Once you’ve determined your sprayer’s spray rate, you can calculate how many gallons of sprayed product you can expect per acre. With this number, you can mix your product accurately for your equipment capabilities and acreage.
Make sure you watch the video above for more tips, as well as a demonstration of the 1/128th calibration method using my sprayer and tractor.