With input prices as high as they are, every farmer is wondering the same thing: how do I make my operation as efficient as possible? One route to better efficiency in your fields is fertigation and chemigation. But you’ll need the right equipment to enjoy that ROI.
What is fertigation / chemigation?
Chemigation uses irrigation to spread chemicals like pesticides or fungicides. Fertigation is a subclass of chemigation that refers specifically to distribution of fertilizer through the irrigation system.
Both processes use technology to get crops the nutrients or protection they need to grow. Chemigation and fertigation are both a far cry from the alternative: having to use your tractors to make applications yourself.
It’s an up-front investment to set up fertigation equipment. But it can offer many long-term benefits and cost savings: uniform distribution of chemicals and fertilizers (which can improve yields), reduced labor time, less runoff, and better nitrogen use efficiency (especially if you use fertigation software like N-Time™ for nitrogen management), and more.
It can feel daunting to set up a chemigation or fertigation system, but it doesn’t have to be. You just need to start with the right equipment.
And we’re here to help.
What are the components of a fertigation system?
1. Irrigation system
This is where it all begins: you can’t have chemigation without an irrigation system. Here are a few different system types:
Drip: Localized water distribution, where pipes deliver water droplets directly to plant roots.
Pivot: A sprinkler system on top of a wheeled tower moves in a circular pattern around a field, distributing water as it goes.
Linear: Sprinklers move a designated distance back and forth across a field.
Sprinkler: Mimicking rainfall, sprinkler sets distribute water from stationary location(s) in the field.
2. Chemical pump
Chemical pumps could be powered through electricity or hydraulics, and can work in several different ways (pistons, diaphragm, positive displacement).
Capacity-wise, you’ll want to choose the size of your pump depending on the expected maximum injection rate for your fertilizer or chemical application. In general, fertilizer pumps tend to have higher injection rate capacity than chemical pumps.
3. Chemical tanks
This is the device in which fertilizer or chemicals are stored – anywhere from double-digit gallons to multiple thousands of gallons. Tanks can be either stationary or mobile.
Some things to keep in mind for a stationary tank: they might need to be located on concrete, or a certain distance from any wells on your property. There might also be limits on the size, according to manufacturer or state regulations. Tank height, width, and position can also be an important consideration for pivot and linear irrigation systems. You don’t want the tank to interfere with the motion of your irrigation system. These stationary tanks can be great for maintaining storage at the field, especially if you want to be prepared for quick-response fertigation.
Meanwhile, mobile tanks are great for refilling those stationary ones, or when you’re already moving pumps between irrigation systems. Mobile tanks and pumps can even be integrated on the same trailer to move together field to field.
4. Filters
Chemical filters are typically placed between the tank and pump. They can prevent sediment or debris from entering the pump.
You could have a screen filter (think of this like a net trapping sediment), a disc filter (a stack of round discs that allows water to pass through, but traps other material) or a sand filter (contaminants are filtered out as material runs through a tank filled with sand).
It’s important to regularly check your filters, since clogs can prevent fertilizer from passing through the pump. This means the chemical injection into the irrigation water isn’t as accurate or successful.
5. Hoses and valves
You will need to use hoses and valves to route fertilizer and other chemicals from tank to pump and from pump to injection point. Ensure these hoses are appropriately sized (diameter, length) and are of a durable material (polymer-based). To secure the connection, use hose clamps or barbs to attach hoses to inlets and outlets.
You should select valves to match the inlets’ and outlets’ size. This allows appropriate flow between components, and can be easily interchanged if needed. Cam-lock couplings are really handy for connecting hoses with tanks and pumps. Easy levers to move on valves are also important.
6. Protective equipment
All irrigation systems must have a backflow prevention valve, a low-pressure drain, and a vacuum relief valve.
But regulations require that your chemigation system also:
Interlocks the chemical pump power and irrigation system power. This means the pump kicks off when irrigation shuts down.
Has a chemigation check valve. This will prevent chemical injection from happening until the irrigation water back pressure is past a certain amount (typically 10 or 15 psi).
Another possible recommendation is to interlock the fertigation pump and the solenoid valve for chemical entry.
7. Power Source
Successful chemigation hinges on having a reliable power source. For electrically powered pumps, you should ensure electrical connections are configured for the appropriate voltage and current draw. Plan to match the plug to the receptacle configuration(s) for your fields. Understand whether your pump requires single-phase or three-phase power.
For hydraulically powered pumps, ensure there’s adequate flow and pressure.
How to properly use and maintain your fertigation equipment
But installing fertigation equipment is only the first step. You’ll want to properly use and regularly maintain all these components to make sure you’re getting the best bang for your buck.
The first step to a successful chemigation or fertigation application is to ensure all valves are open (tank to pump, pump to injection hose) and that the pump is receiving power. Before starting an application event, check that the pump is properly calibrated to inject fertilizer at the right rate in accordance with your irrigation settings.
Calibrating a pump involves measuring how much fluid the system pumps in a period of time. (We’ll dig into the different methods for doing this in a future blog post.) But first things first: proper calibration and system function start with proper equipment maintenance.
A regular maintenance checklist can help:
Prevent clogging, uneven distribution, or equipment failure
Maintain oil levels in your pump
Keep the pump, hoses, filters, sprinkler, etc functioning properly
Ensure the system is uniformly applying fertilizer / chemicals
Here are a few common problems we see – and solutions to enact:
Uneven distribution? You could have a clog in the system. Check your injectors, and either clean or replace them as needed. You’ll also want to ensure that all of your valves are installed correctly and hoses are properly sized.
Tank running out of fertilizer? Make sure you properly calibrate your pump’s output to your irrigation settings.
Plant damage? There could be contamination within your system. Make sure to clean your storage tanks!
Equipment failure? While infrequent, you will still likely need to replace certain parts eventually. Maintaining appropriate oil levels and changing oil in pumps is a good practice. Additionally, winterizing pumps helps maintain their function. With proper maintenance, a quality fertigation pump can last for 30 or more years.
On top of monitoring the above equipment for problems, you’ll also want to proactively adjust your equipment for optimal performance. Keep track of your pH and EC levels in chemicals you pump. To avoid precipitation and solid buildup, make sure the chemicals you mix in your tanks and run through your pumps are compatible.
Another pro tip we’ve seen be very effective for farmers: keeping spare chemigation parts in your farm truck (misters/injectors, valves, teflon tape, etc.).
Having internet-connected fertigation software and a good digital controller can help you stay on top of injection malfunctions and make calibration straightforward – preventing problems before they happen.
Investing in fertigation is investing in your farm’s future
It takes careful planning, up-front investment, and intentional equipment selection to make sure your chemigation system is working for you. Getting the right pieces in place – and maintaining them – helps you reduce labor costs, improve application uniformity, and prevent runoff. But most importantly, building that chemigation system will mean your crops get the right amount of chemical or fertilizer they need – when they need it.
The fertigation/chemigation space continues to innovate rapidly. New technology and new automations are coming onto the market every day. And one especially important advancement has been technology’s ability to integrate with precision ag tools. Fertigation software like N-time™ can help you optimize your nitrogen management, reduce wasted applications, and even calibrate your pump settings.
For help managing crop nutrients and setting up a chemigation system, contact the team at Sentinel here.