The farm equipment industry offers a wide variety of three-point- mounted and trailed types of granular fertilizer spreaders. Most brands of spreaders feature single or double spreading discs to deliver the product onto the field.
No matter the brand or style, proper maintenance, storage and field settings ensure trouble-free and accurate spreader performance.
Remember, fertilizer products are extremely corrosive. Be sure to wear proper eye, hand and body protection when working on or operating your fertilizer spreader.
Cleaning and storage
Proper cleaning and storage helps prolong the life of the machine and ensures more precise and accurate spreading.
Basic steps for cleaning your fertilizer spreader include:
- Empty the hopper on the spreader of any remaining product.
- Remove all granules and fertilizer residues from the hopper and spreading components using high-pressure air with an approved air nozzle.
- Thoroughly wash the spreader and allow time for it to dry. (Be sure to not allow water on the areas of the spreader that have electrical components and wiring if so equipped.)
- Lubricate the spreader according to the manufacturer’s instructions.
- Store the spreader in a clean, dry location out of direct sunlight.
- Maintenance
Each season, before heading to the field with the spreader, perform an inspection to ensure it is safe and mechanically sound to operate. As part of the check, confirm all safety guards and components are in place and in good condition. (This would also include protective guards for PTO drivelines if so equipped.)
Check all fasteners and load-bearing components for tightness and good working condition. Finally, confirm the spreading discs and other related components and fasteners are tight.
Note: Any worn or damaged spreading components could result in inaccurate rate applications and uneven spread patterns. These components should be replaced as necessary. If the spreader is equipped with lighting, ensure it is in proper working condition.
Spread calibration
Proper spreader settings, along with calibration, are key to efficient and accurate application of the selected fertilizer product. Failure to follow these calibration steps can cause costly over-application. While over-application could harm the crop, under-application will affect crop growth and yield.
Due to the variation among fertilizers, it is also important that the settings are set accordingly and calibration is done each time a new fertilizer product is being applied to a field.
Follow these tips to help you identify the right calibration for your spreader:
- Identify the fertilizer product that will be spread in the field along with the density of the product (pounds per cubic foot). Density is an important factor when it comes to spreading because it can affect the distance and distribution pattern of the fertilizer.
- Confirm the target application rate (pounds per acre), working width and ground speed you are to working to attain. Also check if you are performing a normal or late top dressing, as some settings on the spreader could be affected by this.
- Select the most applicable spread chart (normally supplied by the manufacturer) and adjust the spreading components using the spread chart settings. With spreader brands that incorporate an electronic control unit, you will enter the spread chart information into the settings screen of the control box.
- Calibration of the machine settings will ensure the application rate of the spreader can be obtained. The physical properties of fertilizer can vary widely, but by performing a calibration you can “fine-tune” your settings as needed. Depending on the brand and model series, a static flow test can be performed to confirm the settings are correct and will produce the desired results.
On some spreaders, incorporating an electronic control unit and actuators with the control box will allow it to monitor and adjust the settings as necessary. An operator can also perform a practical field check by loading the specific amount of fertilizer per acre selected and making a test run in the field.
In addition, a tray test can be conducted to check that the spread pattern and fertilizer are both evenly distributed. Some manufacturers offer a tray test kit, or you can work with your local agriculture co-op to learn more about this service.
Remember, there are many variables, both controllable and uncontrollable, when spreading fertilizer products. Be sure to maintain a constant ground speed based on the spread chart setting for the rate you have selected. Also avoid applying fertilizer products when there are high winds.
Operators manual
One of the most important “tools” to determine the proper maintenance, storage and machine settings on your fertilizer spreader is the operators manual supplied by the manufacturer.
The manual provides procedures for proper cleaning and maintenance as well as instructions to set the spreader for specific fertilizer products that could be applied to the field. Be sure to follow the guidelines set for your specific machine model and style.
It all starts with proper setup, maintenance and care of the spreader. By paying attention to these basic tips, you can maximize the performance of your fertilizer spreader and receive a higher level of accuracy, providing more cost savings for you by using less product. 
Ed Skeele is a technical support specialist with Kuhn North America.
