11/01/2021 | Agriculture and Farming | 9 MINUTE READ

Agricultural Technology: Fertigation Control Systems

If you’ve been growing crops with a hydroponic system, an important aspect of any hydroponic system is making sure that your plants receive the proper nutrients. One method you can use to introduce nutrients to your crops involves fertigation, which is a unique system that combines irrigation and fertilizer. If you opt for a fertigation control system, treated water will be sent to the crops at different intervals during the growth cycle, which should help with nutrient absorption.

The fertigation process is typically straightforward and can be accomplished with distribution pipes, a pump, an injector pen, and capillaries. An advanced fertigation system offers extensive automation to ensure comprehensive support for your grow room. Since these systems are designed to inject supplements, fertilizer, and acids into irrigation water before the water is sent to the crops, at least one of the injectors will need to be controlled directly by computer software, which ensures precise control over the number of nutrients or acids that are injected.

If your fertigation control system uses computer software, it’s possible to set fertilizer recipes and irrigation frequency based on numerous factors, the primary of which include the weather and your production schedule. Before selecting a fertigation control system, it’s important to understand that these systems can be outfitted with many different types of equipment.

Aside from a computer and fertilizer injectors, a fertigation control system can also be equipped with pH sensors that allow for better nutrient control. There are a wide range of different models that you can select from. Even though fertigation systems are commonly used for large farms and sizable industrial facilities, it’s possible to purchase a small-scale system that can be used in a greenhouse or home garden. The following provides an in-depth guide on fertigation control systems and how they can be a boon to hydroponic growers.

Benefits of a Fertigation System

fertigation control system

When you purchase a well-made fertigation system, you’ll automatically benefit from better accuracy and more automation when growing crops. You’ll have flexibility in the grow parameters you set as well as how you mix recipes. In the event that you purchase an advanced fertigation control system, it’s possible to send nutrient batches to as many as 14 separate zones, which are connected to a single central mixing tank. Additional features available with advanced fertigation systems include:

-Nutrient delivery scheduling
-The ability to correct pH levels
-Email alerts for malfunctions or completed tasks
-Remote control access, which reduces downtime

In general, these systems are designed to help growers save both time and money on a long-term basis by automating nutrient delivery and irrigation, which allows you to spend your time on other important tasks. This system can be very easy to use. However, the overall ease-of-use of a fertigation control system depends on the exact system that you choose. Some additional benefits that you could receive by purchasing a fertigation control system include:

-A reduction in the amount of fertilizer you need to use
-Fertilizer leakage prevention
-Promotes fast root growth
-Lessens soil erosion
-Eliminates nature pollution because of a reduction in chemical applications
-Tips to Selecting a Fertigation System

Because of how many different types of fertigation systems are available on the market, it’s important that you know how to find a system that meets your exact needs. For instance, if industrial facilities purchase a fertigation control system that isn’t large enough, they will have likely wasted their money and may need to purchase a second fertigation system or replace the one they’ve just bought.

1. Test and Treat Incoming Water

The first and most important step to take when attempting to select the right fertigation control system is to test and treat any incoming water. The quality of the water will determine how much treatment is needed before the water can be directly applied to your crops. If you’re dealing with rainwater, the most common treatment methods involve UV treatment or multi-stage gravel filters. On the other hand, a reverse osmosis system is likely your best option when treating well water.

In the event that your well water contains low conductivity levels, it’s possible that further treatment is unnecessary. You can consider skipping the water treatment stage if the conductivity levels of a water sample are at 0.3 or less. Water conductivity can be tested with a conductivity sensor, of which there are many different options to select from.

When you use a reverse osmosis system, the minerals that are initially taken out of the water will typically be reintroduced via fertilizer. The main issue with using an RO system is that getting rid of the brine solution that the RO process produces can be difficult. No matter which system you use, it’s important that the rainwater and well water you use is tested on a regular basis.

2. Reuse or Run-to-Waste

When the irrigation process occurs, you have two distinct options in how you handle fertilizer and water runoff. You can either capture the runoff and properly dispose of it or dispose of any accumulated leachate. The ideal runoff amount for hydroponic growers is around 10-30%. If you use a standard run-to-waste system, the leachate will flow out of your grow room or greenhouse. As such, you may be required to get rid of the minerals that are present in the water before disposing of the leachate.

The more environmentally-friendly system is the one that reuses the nutrient and water mixture. These fertigation systems have a closed-loop design that involves capturing, treating, and eventually reusing the runoff. You’ll need to capture the leachate in trays or troughs, after which it can be pumped into a holding tank. Your system may contain a cloth filter, which will essentially remove fibrous particles before the leachate reaches the holding tank.

The water will then be treated with chlorine dioxide, UV, or ozone, which ensures the eradication of waterborne pathogens. Once the leachate has been treated, it will be combined with fertilizer and freshwater before it’s sent back to your crops, which makes this the ideal fertigation system for hydroponics. Even though reuse fertigation systems are more environmentally friendly, these systems require more space as well as additional equipment when compared to run-to-waste systems.

3. Using Environmental Controls

Another key component of fertigation control systems involves using environmental controls. The environmental control software can be used to manage a fertigation system, which is why it’s important that you choose software that’s able to handle all of the equipment you plan on installing. The type of software you obtain depends on the complexity of your growing operation.

If you are engaging in vertical farming, your grow operation will be considerably more complex than most because of the need for numerous solenoid valves and multiple levels of cultivation. Even though fertigation systems can be outfitted with decent environmental control software, it’s highly recommended that you opt for control software that can manage your entire grow facility.

Positives and Negatives of Fertigation on Plants

Despite the many benefits of using fertigation for your grow area, there are positives and negatives towards using these systems for your plants. It’s important to understand that many different plants require nutrients that aren’t found in basic soil. While you can add an ample amount of organic compost to the soil to introduce the proper nutrients, this isn’t always a practical option. By making use of a fertigation system, the nutrients and compounds that can be added to your plants include:

-Ammonium nitrate
-Potassium chloride

If you decide to use a fertigation system in your home garden, keep in mind that both uniformity and control will be compromised. The fertilizer of your choice will be applied to your crops at the exact same rate, which can be an issue due to the different nutrient requirements for each plant.

In the event that the fertilizer doesn’t combine properly with the water, foliage burn is a possibility. This particular issue can be resolved by adding a few feet of pipe between the injector and sprinkler head. If you are using a fertigation system on a single type of crop or very similar crops, these systems have hardly any downsides.

What to Consider for Successful Fertigation

If you want to make sure that your fertigation system is successful at providing crops with the nutrients they require, there are many factors to consider. First of all, it’s not enough to add fertilizers to irrigation. Some of the properties that you should take into account include compatibility, salinity, solubility, and acidity. When searching for soluble fertilizers, there are two options at your disposal, which include solid fertilizers that can be efficiently dissolved and liquid fertilizers that have already been dissolved.

Before you select a fertilizer for your fertigation system, keep in mind that temperature affects solubility. Higher temperatures lead to higher solubility. Chemicals like ammonium nitrate are twice as soluble when you increase the temperature from 32 degrees Fahrenheit to 86 degrees Fahrenheit.

When considering the chemicals that are being used in your fertigation system, it’s important to understand that high solution acidity can lead to corrosion on any metallic parts in your fertigation system. Chloride-based chemicals are known to cause extensive amounts of corrosion. Consider diammonium phosphate if you want a higher pH in your solution. Even at low concentrations, chemicals like nitric acid would substantially reduce the solution’s pH levels. If you want your fertigation system to be long-lasting, it’s important that you take pH into account.

Whether you’re engaging in hydroponic growing or vertical farming, fertigation control systems allow you to introduce water and nutrients to your crops in an efficient and automated manner, which allows you to save time and money.

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Posted by Sensorex on November 1, 2021

Sensorex is a global leader in the design and manufacture of quality sensors for water quality and process applications. The company offers more than 2000 sensor packages for pH, ORP, conductivity, dissolved oxygen, free chlorine, chlorine dioxide, UV transmittance and other specialty measurements, as well as a full line of sensor accessories and transmitters. Its expert technical support engineers solve analytical sensor challenges with custom designs and off the shelf products.

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