Fertilizer injectors are gaining popularity among farmers in Kenya, particularly those using drip irrigation. These instruments assist in applying liquid fertilizers precisely to the crops’ root area, enhancing the efficiency, accuracy, and affordability of fertilizer application. This article will explain what fertilizer injectors are, how they function, their various types and features, and where you can purchase them in your area
What are Fertilizer injectors?
A fertilizer injector mixes liquid fertilizer with irrigation water, delivering the combination directly to individual plants through the irrigation system. This saves farmers time and fertilizer, enhances plant health, and increases yield. Fertilizer injectors are widely used at greenhouses, in open fields, and horticulture farms throughout Kenya.
Which fertilizers are applied using Fertigation Kits?
Fertilizer injectors are used to apply water soluble fertilizers and pesticides to plants through irrigation systems.
The Venturi injector is the most widely used device due to its simplicity, as it directly injects fertilizer or chemicals into the system by only maintaining the correct pressure difference.
Cost of Fertilizer Injectors in Kenya
Fertilizer injectors cost between KES 2,000 to KES 5,500 depending on the size and the specifications.
Features of Venturi Injectors
- Adjustable Injection Rates: Allows you to change how much fertilizer is mixed with water.
- Compatibility with Your Irrigation System: Make sure it fits your pipes and pressure range.
- Ease of Maintenance: Simple systems are easier and cheaper to maintain.
- Durability: Choose injectors made from corrosion-resistant materials, especially if using chemical fertilizers.
Common Types of Fertilizer Injectors
- Venturi Injectors
- These are affordable and simple to use. They operate using pressure differences in the irrigation line.
- They don’t require electricity or a motor.
- Ideal for small to medium-sized farms.
- Dosatron (Non-electric) Injectors
- These use water pressure to operate and allow very precise mixing.
- Good for medium to large farms.
- More expensive than venturi but more accurate.
- Electric or Motorized Injectors
- Use pumps to inject fertilizer into the system.
- Suitable for large commercial farms or greenhouses.
- Highly accurate but require electricity and regular maintenance.
How Do They Work?
Fertilizer injectors suck liquid fertilizer from the tank and discharge it to the irrigation line for feeding at crop root zones. The rates of fertilizer being suctioned to the system can be controlled in most fertilizer injectors and thus the right amount is fed to the crops.
Considerations when Buying Venturi Injectors
Certain factors outlined below should be considered when buying a venturi injector from the market.
- Peak pressure at the Pump/ Head Unit set up in the field.
- Field pressure at which the sprinklers/drippers operate in the field.
- Review the performance chart and verify the inlet and outlet pressure present in your area for proper selection.
- Evaluating the effectiveness of the venturi injector under conditions of minimal pressure difference between the inlet and outlet.
- Purchasing the venturi based on the necessary injection rate and the inlet and outlet pressure.
- Choose the venturi injector equipped with a check valve at the suction inlet.
- Purchase the venturi injector along with its side assembly from the same manufacturer; avoid sourcing and assembling parts from various companies.
- Keep in mind that all branded companies offer venturi (fertigation) options in various sizes from ¾” to 2” according to the needed fertilizer injection rate
Sizing Your Fertilizer Injector
To choose the right injector for your drip irrigation system:
- Understand your Irrigation flow rate: the rate of water flowing through the system determines the compatible size of fertilizer injector.
- Determine Injection Rate: Decide how much fertilizer you want to apply, usually given as a percentage (e.g., 1% means 1 liter of fertilizer for every 100 liters of water).
- Match the Injector Capacity: Make sure the injector can handle your flow rate and desired injection ratio.
For example, if your system flows at 1,000 LPH and you want a 1% mix, your injector should handle at least 10 liters per hour of fertilizer solution.
How to Install Venturi Fertilizer Injector
Always remember that a Venturi Injector must be installed in a horizontal or vertically upward orientation, aligned with the direction of flow (as indicated by the flow arrow). Installing in a vertical downward position can result in inconsistent or unpredictable suction from the injector.
Always utilize “full flow” valves and fittings when linking to a venturi injector. Do not utilize pipe fittings that are smaller than the thread size of the venturi injector. (It’s advisable to purchase the side fittings from the same manufacturer.)
Avoid excessively tightening venturi injectors when securing them to pipes or fittings. It is advisable to use a thread sealant or tape.
Venturi injectors need a pressure difference to function correctly. Typically, for notable suction to happen, the outlet pressure should be at least 25 – 30% lower than the inlet pressure.
Pressure gauges are advised for measuring the true pressure difference
Common Issues with Fertilizer Injectors
- Low Water Pressure: Venturi injectors rely on pressure differences; if pressure is too low, they won’t work properly.
- Clogging: If fertilizer is not properly dissolved, it can block the injector or drip lines.
- Incorrect Sizing: Using the wrong injector size can lead to under- or over-fertilizing.
Solutions
- Use a Filter: Always install a good filter before the injector to prevent clogging.
- Pre-dissolve Fertilizer: Make sure your fertilizer is fully dissolved in water before injecting.
- Use a Pressure Regulator: Helps maintain consistent water pressure.
How to Troubleshoot Venturi Injectors Not Working
A few straightforward steps can help identify if the venturi is functioning properly:
Step 1: Verify if you sense the suction when the suction line is detached and the injector is functioning.
Step 2: While the suction line is detached and the injector is functioning, carefully press the ball within the internal check valve on the suction port (a slim, blunt instrument should be utilized for this task). Verify if the water jets out of the suction port.
Step 3: If suction is evident and water does not spray from the suction port while in use, the injector is creating a vacuum and functioning correctly. If you do not sense suction and water sprays out from the suction port while in use, the injector is failing to create a vacuum.
Step 4: Verify whether the Injector is faulty. It can be harmed by excessive tightening, from shocks, or from enduring too much torsion. If you believe this might be true, check the injector for any cracks, holes, or other indications of damage. Replace the injector if any of these indications of damage are detected
Where to Buy Fertilizer Injectors in Kenya
Aqua Hub Kenya Ltd has quality venturi fertilizer injectors available at sizes of 1, 1 ½ and 2 inch.
Call 0790719020 to buy.
