Info Updates
An archive of Chemigation and Fertigation technical knowledge
This page is based on past Info Update dealer newsletters published by Chemigation Systems International on various aspects of Chemigation and Fertigation. You can search this page for your topic using your browser's "find" function.
About Fertilizer Injectors
Q: I want to sell injectors. What injector models should I offer my customers?
A: More than 70% of injectors are used for fertilizer only. So, it makes sense that fertilizer injectors should be your first injector sales priority.
Q: How is a fertilizer injector different from a chemical injector?
A: They work in similar ways, but here are a few important differences:
Usually, fertilizer injectors are higher in capacity than chemical injectors.
Most fertilizer injectors are standard machines. Chemical injectors vary widely, depending on the job they must do.
In chemical injectors, parts in contact with concentrated chemicals are usually made out of more corrosion resistant materials than similar parts in fertilizer injectors.
Because of the higher cost of some corrosion resistant materials, chemical injectors are a bit more expensive than fertilizer injectors of the same capacity.
Q: What is fertigation?
A: Just a fancy name for feeding fertilizer through an irrigation system. Similar terms are: insectigation, herbigation, and fungigation. All of these are parts of the overall technology called chemigation.
Q: It sounds like I should ignore the chemical injection part of the business and just concentrate on fertilizer injectors.
A: Not so! You have to start somewhere and all we’re talking about here is putting first things first. Later in this series we’ll discuss injection of liquids other than fertilizer.
CSI builds fertilizer injectors and chemical injectors in 5 basic capacity ranges:
0 to 3 gph
0 to 15 gph
0 to 60 gph
0 to 160 gph
0 to 400 gph
Injector Types
Q: What kinds of injectors are used to inject fertilizer and chemicals into irrigation water?
A: Two main pumping technologies are used:
Venturi Injection: A venturi is a device which creates vacuum when fluid flows through it. The fluid which creates the vacuum is known as the "motive fluid". The motive fluid for irrigation injectors is the irrigation water itself. Vacuum created by the venturi sucks fertilizer or chemical into the motive water.
Reciprocating pump injection: Even today, many injectors use reciprocating action to pump fertilizer and chemicals from feed tanks into the irrigation line. Injectors of this type use either a stroking piston or a flexing diaphragm in combination with check valves to inject a pulsating stream of liquid.
Q: How are irrigation injectors powered?
A: It takes energy to inject into irrigation pipelines. Before injection takes place, the fertilizer or chemical is in a feed tank at atmospheric pressure. After injection, the fertilizer or chemical is inside the irrigation pipeline at a higher pressure. There are 2 practical energy sources for this pressure boost:
Powered: An external power source (usually electricity, sometimes an engine) powers the injector. External power allows the injector to run without reducing flow or pressure in the irrigation line.
Water driven: Some injectors are designed to be driven by the flow or pressure of the main irrigation pipeline. Some reciprocating pumps and venturi injectors are designed to be water-driven. But there is no free lunch! The energy to run these devices always reduces the irrigation water flow and/or pressure from what it would be if the injector got its power somewhere else.
CSI specializes in powered venturi injectors (mostly electric, but also some gas-powered). We think that powered venturi injectors are:
easier to use
more reliable
easier to maintain
safer
...when compared to reciprocating pump injectors.
More About Fertigation
Q: What materials do growers apply by fertigation?
A: Most frequently, bulk commodity
liquid fertilizers are injected. In most parts of the country these are solutions of
urea and ammonium nitrate containing 28% or 32% Nitrogen. In a few regions, bulk
chemical plants produce other concentrations of liquid fertilizer. You can learn the
specifics in your market area by asking your county agent or local growers.
Some growers inject custom liquid fertilizer blends. Think of these as
"prescriptions" based on specific crop requirements and soil analyses.
Typical formulas include:
major nutrients: Nitrogen, Potassium, Phosphorus
minor nutrients: such as Sulfur, Boron, Magnesium
micro nutrients: such as manganese, zinc, copper
Some growers make their own liquid fertilizer by mixing soluble granular fertilizer with water in the injection tank. Concentrations are often as high as 5 pounds granular per gallon of finished liquid.
Q: It sounds like I need to learn a lot about crop nutrition.
A: The good news is that you don’t need to know much about chemistry to sell fertilizer injectors. Mainly you need to know enough to answer one question:
How many gallons per hour does the customer need to inject?
In most cases, the customer will answer this question for you. But if you need to figure the rate for him, a future edition of the CSI INFO/UPDATE will show you how.
CSI's new catalog and brochures are now being distributed. Every irrigation dealer sales person in the US and Canada should have a copy of this catalog. If this FAX INFO/UPDATE is addressed to you, your catalog should soon be in your hands.
If you have sales colleagues who don’t receive personal copies of our INFO/UPDATES, please send their names to us so we can add them to our list of irrigation sales professionals.
Rules of Thumb for Sizing Fertilizer Injectors
Q: I sell pivots. Is there a rule of thumb for sizing an injector for a typical 1/4 mile pivot?
A: Different rules of thumb apply, depending on the way pivots are used in your region.
Arid farming areas: On the High Plains and in other arid areas, almost 100% of crop water requirements are met by irrigation. Growers in these regions typically use small injector pumps and run them many hours per year. The typical fertilizer injector that CSI sells on the High Plains is the 0 to 15 gph model. Some growers who apply Nitrogen at rates which closely balance crop uptake buy CSI's 0 to 60 gph model so they can increase fertilizer feed rates at critical stages of plant development.
Areas where irrigation is supplemental to natural rainfall: In the Midwest and other regions where there is significant natural rainfall, growers buy larger fertilizer injectors so they can apply the required fertilizer during fewer hours of irrigation. In these regions, CSI's 0 to 160 gph injector is the most common size.
We have noticed that progressive growers tend to run larger fertilizer injectors than less-advanced growers in the same region. Better farmers recognize that bigger injectors are a low-cost investment in flexibility. You can help your customers and increase your own revenues at the same time by convincing them of the advantages of replacing existing injectors with higher capacity models.
An interesting example: During the wet 1993 crop year in the Midwest, many irrigated growers found that pivots were the only option they had for fertilizer application on muddy fields. Those who owned big injectors (like CSI's 160 gph model) were able to save their crop by feeding maximum fertilizer into pivot water.
Q: I sell drip irrigation. Are there any rules of thumb for fertilizer injectors in my part of the business?
A: The variations in drip irrigation are much wider than in pivot practice. However, CSI finds that most injectors which go into drip installations are 0 to 15 gph or 0 to 60 gph models.
Here is a list of some of CSI’s most popular fertilizer injectors:
160SE3K 460V 0 to 160 gph injector, powered by 3-phase 460 Volt electric motor, with 3-phase starter/overload and installation kit.
160GK As above except powered by a Honda gas engine.
60SE3K 460V Like the first one except that capacity is 0 to 60 gph.
15E1K 110V 0 to 15 gph injector, powered by single phase 110 Volt motor, with installation kit.
About Chemical Injectors
Q: Earlier in this series you promised to tell us about injecting chemicals other than fertilizer.
A: This seems like the right time to talk about chemical injection. Here’s a list of some of the chemical classes that can be applied through injectors:
| Herbicides | Nematicides | Algaecides/slime control agents |
| Insecticides | Soil fumigants | pH control chemicals |
| Fungicides | Soil penetrants | Other water treatments |
There has even been work done on injecting beneficial organisms into several types of irrigation systems and on injecting air into underground drip systems. It is likely that the range of injection applications will continue to grow.
Q: If 70% of injectors are fertilizer only, why not just ignore the rest of the chemigation field?
A: That’s exactly what many of your competitors do and this means there is less competition (and sometimes higher margins) in the rest of the chemigation field than in fertigation. If your firm is known as a full-service injector supplier, you are more likely to be the first to be contacted by injector customers,
Almost always, chemical injectors cost more than fertilizer injectors of similar capacity. This is because some chemical injector components are made from more costly materials than similar parts on fertilizer injectors. Also, customers who use chemical injectors often want to do complex things with them, so they need more features. Some injector customers need to inject 2, 3 or even 4 chemicals, sometimes simultaneously, with the same machine.
If you want new markets for your business, chemical injector sales can bring you into contact with more diverse customers such as golf courses, greenhouses and nursery operations.
Q: What are the most common sizes for chemical injectors?
A: CSI finds that most chemical injectors are the 0 to 3 gph and the 0 to 15 gph models.
Look to CSI to support your chemical injector sales efforts. We offer fast delivery on a wide range of machines. We can inject 1, 2, 3 or 4 chemicals at once or in sequence. And we can supply controls to satisfy your customer’s automation requirements.
Economics of Chemigation
Q: Some irrigated growers still use ground application methods for fertilizer and chemicals. Can they save money by switching to chemigation?
A: Absolutely! On big acreages, the cost of applying crop inputs with ground application equipment is at least $2.00 to $3.00 per acre higher than applying the same materials through an irrigation system. On smaller spreads, the cost difference is even more.
Q: I guess chemigation looks even better when compared to aerial application?
A: In most places, aerial application adds at least $4.00 per acre over chemigation.
Q: I’ve seen claims of much higher per acre savings. What’s the story?
A: We’ve seen savings claims as high as $12.00 per acre. It’s possible that these claims are accurate in special situations. However, these extreme savings aren’t seen by most chemigators. In any case, you don’t need to exaggerate: The conservative numbers above are enough to convince any good grower/businessman that he should buy and use injectors.
Q: With such large potential savings, why isn’t there an injector on every irrigation system?
A: That’s a really interesting question. We’ve heard a lot of theories, but the truth seems to be that good news spreads slowly. In some parts of the country, every irrigation system has an injector. But in other regions, only a few injectors are in service. If you are in an area with few injectors, it’s worth your while to be a missionary for chemigation. If you sell in an area where everyone has an injector, you can still generate replacement business.
Financial benefits are only part of the story. The best news is that Chemigation does the job better than competing application methods. More on this in the next CSI INFO/UPDATE.
You’ll feel good selling CSI injectors to growers who are new to fertigation and chemigation. Simple operation of CSI injectors means new users can concentrate on what they want to accomplish instead of worrying about too-complicated equipment.
And you’ll like selling CSI injectors as replacements for less-advanced or worn-out competitors’ units. CSI injectors work well and last a long time, so you can talk about low cost of ownership. And you can do an extra service for many customers by convincing them to buy bigger injectors than they have used in the past. A bigger injector is a low cost investment in flexibility.
Go for your share of the injector business! Order one or several CSI injectors for stock.
Technical Advantages of Chemigation
Q: You’ve convinced me that fertigation and other chemigation methods can save money for my customers. But do they do as good a job?
A: Even better! A lot of ag research stations have investigated the application of chemicals through irrigation systems. Typically they find that fertigation provides the following advantages compared to ground application:
Higher crop yields due to precise application of fertilizer
Lower total nutrient application rates
Able to more closely match fertilizer application rates to crop uptake rates
Ease of changing fertilizer formulation during the season
Reduced soil compaction because less equipment runs in the field
No "striping" due to skipping, overlaps, and plug-ups
Reduced crop damage because less machinery runs in the field
Reduced run-off of agricultural chemicals
Lower risk of ground water contamination
Lower energy requirements
Q: What about chemicals other than fertilizer?
A: Most of the above advantages extend to pesticide injection. In addition, researchers report:
Lower exposure risk to application personnel,
Less difficulty with drift
Q: How does all this fit together with some of the newer irrigation technologies?
A: Two technological advances offer us examples of the perfect fit between injectors and irrigation systems:
Low Energy Precision Application (LEPA) heads make pivots even more effective as application devices. LEPA heads are usually arranged to deliver water beneath the crop foliage canopy. Several LEPA head designs have multiple operating modes including the capability to convert between down-spray and up-spray. This feature further improves the flexibility of chemical application by center pivots.
Sub-surface drip irrigation is a technology that couldn’t exist without injectors. All crop nutrients are delivered directly to the plant roots through the irrigation lines while the search continues for new systemic pesticides that are well-suited for root uptake. Chemicals must also be injected to keep irrigation lines free of slime that would plug the drip emitters.
CSI publishes this series for you ... and we’d like your input. Please let us know how you think we’re doing -- and send us your ideas for any subjects you want us to cover in the series.
Government Regulation of Chemigation (Part 1)
Q: What government regulations concerning chemigation should I know about?
A: The main regulations chemigators deal with are:
- Regs concerning the suitability of particular chemicals for chemigation
- Regs to protect ground and surface water from contamination
- Regs to ensure that suitable injectors are used for fertigation and chemigation
- Regs to make sure that people who apply chemicals are qualified to do so
- Regs to protect workers and the general public from exposure to chemicals
Q: What government agencies write and enforce these regulations?
A: In answering your question I’ll stick to the technical aspects of chemigation -- the first three items listed above. Most regs about ag chemicals and their application fall under the jurisdiction of the federal EPA. But state agencies such as natural resource departments, ag departments or state EPAs often write and enforce additional regulations.
Q: How can I find out if a particular chemical can be applied by chemigation?
A: The federal EPA requires labels of all registered pesticides to say whether or not they can be chemigated. If a chemical manufacturer registers chemigation as a permitted application method, chemigation directions must also be provided on the label.
Q: Are there many products that can be chemigated?
A: The manufacturers of more than
250 products have registered them for chemigation under EPA rules. Chemigatable products
include many widely used pesticides.
TO BE CONTINUED IN THE NEXT ISSUE OF THE CSI INFO/UPDATE...
Government Regulation of Chemigation (Part 2)
Q: What regulations must be followed to protect the water supply when chemigating?
A: The main requirement is to make sure that chemigated irrigation water can’t flow back to the original water source. In most places, a special check valve known as a chemigation valve must be present between the well pump and the point where chemical is injected into the irrigation pipeline. Among other requirements, the chemigation valve must be constructed so that the sealing element can be inspected easily. Several manufacturers make chemigation valves. CSI provides chemigation valves specifically designed for use with CSI injectors.
Where irrigation water is obtained from public water systems, plumbing codes require more elaborate isolation using a device known as a reduced pressure backflow preventer.
Q: What about the injectors themselves? How are they different from regular pumps?
A: A pump is just a component. A fertilizer or chemical injector is a system of components which includes a pump. The regulations require injectors to have two safety features:
1. The injector must block chemical from running out of the feed tank except when the injector is running. On CSI injectors, this requirement is satisfied with an automatic valve in the chemical line. This valve opens when irrigation water pressure is present.
2. If the injector is not running while the irrigation system is running, a second safety device must block the irrigation water from backing up into the feed tank and diluting its contents or overflowing the tank. CSI uses a special check valve to satisfy this requirement.
Q: Are there any special requirements for installing the injector?
A: The regulations require the injector to stop when irrigation water stops flowing, to avoid the injector pumping chemical into an inactive irrigation pipe. If the water comes from an electric irrigation well this is done by powering the injector’s motor with a branch circuit from the irrigation pump, preventing the injector from running if the irrigation pump isn’t running. CSI also has other methods for providing the required interlock in situations where no electrical irrigation pump is present.
Pumped venturi injectors vs. piston and diaphragm pumps CSI's pumped venturi injector systems outperform old-style piston and diaphragm pumps:
|
EXPANDING YOUR INJECTOR SALES
Q: It seems like most fertigation and chemigation systems are just simple injectors that are installed on large agricultural acreages with drip or pivot irrigation. How can we widen the potential market for injectors and sell more upscale products?
A: Almost every corner of the green industry uses irrigation and almost everyone who operates irrigation systems thinks about using them to deliver fertilizer and other plant inputs. You should try selling injectors to the following:
| Greenhouses | Highway departments |
| Nurseries | Military bases |
| Golf courses | Landscape architects |
| Park districts | Commercial landscape contractors |
| Recreation departments | Upscale residential acreages |
Q: Some of the customers you just listed have special injection requirements. What are you doing to help us sell these markets?
A: CSI's traditional product line is one of the widest in the injector business. Think about the following CSI capabilities when selling to customers in new fields:
All injection capacities from very small to very large
A full range of automation options
A wide range of tanks and mixers for dissolving dry materials
Multi-chemical injectors
Trailer systems for park districts, highway departments and the like
...and CSI continues to develop new approaches to fertigation and chemigation. Recent additions to our product line include:
High pressure injector systems: CSI models are now available for irrigation pipeline pressures to 150 psi. High pressure injection is often required for golf courses and other large area turf applications. In the ag world, CSI now provides injectors for high pressure travelling sprinklers.
Flow-following systems: True ratio injection for golf course fertigation and other situations where injection must match varying irrigation water flow.
The above products are the sort of upscale systems that let you add value and increase revenues by solving real customer problems. Many CSI products aren’t available from other sources, so you won’t have a flock of competitors destroying your profit margins.
WHY FERTIGATE GOLF COURSES?
Easier management of fertilizer application: less reliance on operator skill
Reduced application cost: Reduced direct labor. Reduced need for mobile equipment
Uniformity: Fertilizer goes where the water goes, less waste
Easier to avoid fertilizer run-off
Less fertilizer needed for desired effect
Less chance of turf burn
Fertilizer goes to turf roots where it has the best effect
No interruption of golf play
Aesthetics: No granules left on surface of course
Reduced need to operate equipment on turf
"Spoon feeding" fertilizer becomes practical
Easier blending of custom applications
Liquid turf chemicals can be processed through the same system as fertilizer
Reduced PR problems. Chemical application is less visible to golfers and the general public
No direct handling of fertilizer and chemicals by equipment operators
Growing acceptance of fertigation all over North America
WHY FERTIGATE
GOLF COURSES WITH
CSI's AWARD-WINNING TRUE PROPORTIONAL FERTILIZER INJECTORS?
Easy ratio setting and useful operator displays.
Closed loop control: the most accurate proportional fertigation system on the market.
Reliable: controlled injection with simple centrifugal pump and venturi.
Quality flow sensors: Data Industrial flow meters - recognized for accuracy and trouble free service.
Computerized system remembers changes that occur during irrigation system upsets like unexpected shut-downs, and corrects the injection total as soon as possible.
On board centrifugal pump is set up to transfer and/or mix fertilizer/chemical tanks.
Huge rangeability: standard models with maximum flows from 15 gph to 400 gph.
No compromises: high capacity injectors can be turned down to very low injection rates.
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