We all want our plants to grow healthy and strong, whether we’re farmers, agriculturists or just home gardeners. A variety of factors enable healthy foliage, but soil of high quality is among the most important. Growing plants are more likely to thrive in soils with more nutrients.
To improve soil quality, people usually add soil conditioners or fertilisers. This can be done by mixing or adding the fertiliser to the soil. However, there is another method used to apply soil amendments that is delivered through the drip irrigation system itself. This method is called fertigation.
Home fertigation can be an effective way to fertilise plants through your domestic irrigation system. However, it isn’t enough just to add fertiliser to your irrigation water. Fertigation does require some investment in proper equipment, including a fertiliser pump or injector and root feeders to deliver the fertiliser deep into the soil.
From a DIY fertigation set-up to a fertiliser injector kit, there’s a range of ways to achieve this goal. Check out our guide below for detailed instructions on adding fertiliser to your irrigation system.
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What Is Fertigation (Fertiliser Injection)?
Fertigation, or fertiliser injection, combines fertilisation and irrigation into a single process. This is done by adding fertiliser, soil conditioners, and water-soluble products to the water flowing in irrigation pipes.
Essentially, the process aims to fill in a plant’s nutritional deficiencies more efficiently and effectively. Additionally, fertigation uses less water than conventional methods of fertilisation and reduces soil erosion. Many commercial growers prefer this method since it minimises the amount of fertiliser they use and allows them to control the time and rate at which it is released.
Fertiliser injection is frequently used in small-scale horticulture and mass agriculture. The method is also used for landscaping due to dispenser units becoming easier to use and more reliable.
Pros And Cons Of Fertigation
Is fertigation the suitable soil conditioning method for your garden or farm? Read on to find out.
Pros Of Fertigation
Precise Control Over The Dosage Of Nutrients
The primary benefit of fertigation is that the system automatically regulates the nutrients necessary for the plants to grow. The type, blend, and volume of nutrients injected into the irrigation system are typically based on the crop or plant itself and the growing medium used. The process works well in both traditional soil-based and hydroponic setups. The control over the amount and time of nutrient injection gives fertigation an upper hand over traditional methods.
Reduction In Chemical Leaching
Chemicals found in plant fertilisers are often harmful in high concentrations. In addition, the leaching of fertilisers into water sources can cause a severe environmental threat. Leaching occurs when the excess fertiliser supplied to the plant runs into the environment before the plant absorbs the fertiliser. A leaching issue can often arise as a result of rain or over-irrigation.
Fertigation reduces leaching through controlled feeding. The system fertilises the plants at the ideal rate, frequency, and volume for that plant species. This gives the plants enough time to absorb the nutrients and the water, reducing the chance of leaching.
Improvement In The Usage Of Resources
A known benefit of fertigation is the reduction in the amount of waste produced throughout the system, improving growers’ resource management. This process allows precise control over the amount of nutrients and fertilisers since it eliminates fertiliser wasted through hand mixing and traditional watering. This also leads to lower fertiliser costs.
A huge advantage of using the fertigation system is to improve the plants’ root health from a nutrient-rich root system. This results in the plants holding much more water.
Reduction In Labour Costs
Although fertigation systems require daily maintenance, the labour required to operate such systems is inconsequential compared to the amount of labour saved from manually performing fertilising tasks.
Fertigation systems also limit the amount of possible human error in the process. Errors such as the oversaturation of nutrients or an uneven application are significantly lowered through such a system.
Cons Of Fertigation
More Complex And Increased Maintenance
There is an increased level of maintenance involved in fertigation compared to traditional methods of fertilising. Daily inspection for any leak or inconsistent fertiliser feeding is one of the most critical steps in the system’s maintenance. Any leak along the lines can have an incredibly negative outcome on the effectiveness of the entire system.
Routine tasks such as cleaning are vital to ensure that the system’s tanks are devoid of contaminants and sediments. These contaminants may throw off the carefully measured doses of nutrients and fertilisers delivered to the plants.
Ensuring the controls of a fertigation system functioning is perhaps the most demanding aspect of maintenance. Since the primary function is the automation of the nutrient delivery process, computerised monitoring and control are essential aspects of the system. Commercial-scale growers with fertigation systems often hire specialists dedicated to overseeing the optimal functioning of these control systems.
Much Higher Installation Costs
Fertigation systems require specialised hardware to be installed across an existing irrigation system. Understandably, this demands higher costs for the purchase and installation of hardware such as sensors, regulators, control units, and more. In fact, large-scale operations require several of these components.
Can You Fertigate At Home?
Fertigation is often used in bigger lawns and large-scale operations. While possible, fertigation systems are not as common in typical home gardens due to the following reasons:
- Fertigation is effective and economical on agricultural scales. However, for home gardens, it can be impractical to set up unless your existing garden has a functioning drip irrigation system. It’s much more viable to introduce fertigation at home if you have a very precise drip irrigation system in place.
- Since fertigation-fed fertilisers are chemicals, installing a reduced backflow preventer to an existing irrigation system is necessary. However, this piece of equipment is quite expensive by most casual gardener’s standards.
- Usually, your property’s existing irrigation system comes in the form of a home sprinkler system. Unfortunately, home sprinklers often produce significant runoff water saturated with excess fertiliser. Without a proper drainage system to redirect this runoff, it will flow to unwanted places where it will encourage algae and weed growth.
- Nitrogen, commonly injected in typical fertigation systems, easily evaporates in atomised water, such as the water sprayed through a home sprinkler system. Evaporated nitrogen does not reach the plants. Thus, you are actually backsliding on fertilising your plants if used with home sprinklers.
- Chemical-laden overspray (if you’re using your home sprinkler system as a fertigation system) can drift to cars and neighbour’s homes. These chemicals can easily damage their paintwork.
- Fertigation works in large-scale agriculture because the type of chemicals, frequency, volume, and fertilising time is specific to the crop being grown. Home gardens often comprise different kinds of plants—each with its own nutrient requirements. Thus, using fertigation in your home garden actually compromises your plant’s health without a very closely calibrated drip irrigation delivery.
- The automation of a proper fertigation system enables precise measurements of fertilisers and water. Automating such a system is complex and expensive. If you opt to mix your own fertiliser for your fertigation manually, you run the risk of foliage burn.If you think that you absolutely need fertigation for your home garden, it’s best to consult with an irrigation expert regarding your plan.
What Kinds Of Fertiliser Can I Inject Into My Irrigation System?
In theory, all mineral fertilisers can be used in an irrigation system. In practice, however, fertigation usually focuses on the delivery of the primary nutrients required by plants: nitrogen (N), phosphorus (P) and potassium (K).
A wide range of fertiliser chemicals is available on the market. Many of these commercially available fertilisers and soil conditioners are pre-formulated to a specific ratio. The specific fertiliser you need to use depends on the crop or plant, soil conditions, environmental conditions, and plant health.
All liquid and soluble fertilisers can be delivered using more robust fertigation systems. However, a technical grade soluble fertiliser is recommended over agricultural grade products to minimise mineral build-up and blockage.
Here is an overview of the types of nitrogen, phosphorus, and potassium fertiliser used for fertigation.
Nitrogen And Nitrogen Sources
Nitrogen (N) is a prerequisite nutrient for all plants. It’s ideal for fertigation systems because it dissolves completely in water. Other nitrogen sources include urea, ammonium nitrate, calcium nitrate, potassium nitrate, and ammonium sulphate.
‘N fertilisers’ are extensively used to prepare single or multi-nutrient fertiliser solutions. pH-neutral nitrogen sources such as calcium nitrate and potassium nitrate are used as nitrogen fertilisers in fertigation systems. Soils with high pH levels may be given acidic sources of nitrate to reduce the soil’s acidity level.
Examples of nitrogen sources are:
- Ammonium nitrate solution (20-0-0)
- Urea-ammonium nitrate solution (32-0-0)
- Calcium nitrate (15.5-0-0-19 Ca)
- Ammonium thiosulfate (12-0-0-26)
- Urea (46-0-0) or (23-0-0)
- Urea sulfuric acid
- Potassium nitrate (13-0-46)
Phosphorus And Phosphorus Sources
Phosphorus (P) is another necessary chemical for a healthy plant. Adding phosphorus in the later stages of a plant’s life through a fertigation system is done when phosphorous deficiency symptoms appear during the growing season.
Phosphorus, much like nitrogen, is water-soluble, making it one of the ideal fertilisers for fertigation systems. In addition to this, phosphorous is often found in other essential nutrients such as calcium (Ca). A majority of commercially available fertilisers contain phosphoric acid (P2O5) as water-soluble and citrate-soluble phosphate.
Examples of Phosphorus sources are:
- Phosphoric Acid (0-54-0)
Potassium And Potassium Sources
Potassium (K) is another important nutrient for plants. When mixed with other fertilisers, potassium can generate solid precipitants. It’s important to note your potassium fertiliser’s level of solubility; low-soluble fertilisers are not an optimal choice for fertigation.
Examples of potassium sources are:
- Potassium chloride (0-0-62)
- Potassium sulfate (0-0-52)
- Potassium thiosulfate (0-0-25-17) and (0-0-22-23)
Other Nutrients And Their Sources
The vast majority of mineral micronutrients are not used for fertigation systems due to their low solubility in water. This is why micronutrients such as copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) are applied or blended with the soil, not through the irrigation system.
Ready-Made Water Soluble Fertilisers
Australia has a variety of ready-made fertiliser products on the market. These include:
- Water-soluble fertilisers from YaraTera (CALCINET, FERTICARE Vegetables, KRISTALON Blue Label, and more)
- Various Orica agricultural fertilisers
- Incitec Pivot fertilisers
- Eco Seaweed from Eco Organic Garden
What Equipment Is Needed For DIY Fertigation?
There are a couple of components needed to set up a DIY fertigation system. Keep in mind that there must already be an existing irrigation system in place.
Some basic components used to create a DIY fertigation system include:
- A pump to boost water pressure
- A fertiliser injector to deliver the fertiliser into the flowing water
- A backflow preventer to prevent the fertiliser from travelling back to the water supply
- A water reservoir such as a tank or farm pond
- A timer for scheduling the flow
- A flow regulator to regulate the flow of water and fertiliser
- A controller for programming your watering schedule
- An inlet that connects to a garden hose that would allow the water from the primary water supply to flow into the fertigation system.
- A pressure valve which reduces the water pressure to the dripper system’s level, keeping the pressure at a constant rate.
- A ‘T’ connection pipe goes into an on/off tap for the fertiliser.
- An on/off tap controls the water volume of the irrigation system.
- A Venturi valve allows fertiliser products to be siphoned into the fertigation system.
- A drum stores the fertiliser products.
- A space saver float valve with two float positions allowing for water level adjustment
These are the core equipment you need in a DIY fertigation system. You may also need other pieces of equipment, depending on various factors such as your piping layout, terrain, plant type, and more.
Purchasing a fertiliser injector such as the EZ-FLO fertigation kit can be the easiest way to get started with home fertigation. This provides all components including a 2.8-litre Poly Tank, mixing cap, feeding tubes, liquid adapter, plastic tap adapter and quick snap-on fittings. It is also available in a 3.2L version for higher flow applications.
Will Fertigation Damage My Irrigation System?
A properly installed and maintained fertigation system won’t directly damage an existing irrigation system. However, improper use or lack of maintenance may lead to problems in the fertigation process, which, in turn, may affect the irrigation system. The most common problem is clogging created by low-soluble fertilisers, debris, or sediments in the irrigation system.
It is important to keep in mind that not all kinds of fertiliser are compatible with all fertigation systems. The solubility of fertilisers is important, considering that fertigation systems often use water as a medium. Less soluble fertilisers can clog the system.
Related Questions
Does Fertigation Control Alkalinity?
The alkalinity or acidity of the irrigation water is important as it dramatically affects chemical reactions in both the soil and plants. The pH level should be in a specific range to ensure optimal absorption of nutrients and prevent the irrigation system from clogging.
Fertigation itself does not affect the alkalinity of the irrigation water. This is done through other interventions, such as adjusting the amount of acidic nutrients in the system. For best results, the pH level of the water should be consistent and stable.
What Is Chemigation?
Chemigation is a similar process to Fertigation. While fertigation is applying precise and consistent amounts of fertiliser, soil amendments, nutrients, or other water-soluble products through an irrigation system, chemigation delivers pesticides, fungicides, or herbicides are pumped through the same type of system.
Both processes ensure that the water-soluble products are distributed safely and evenly over large areas of land. The uniformity of distribution maximises the effectiveness of such products.
Deciding If A Fertigation System Is Right For You
As with most Agricultural Technology (AgTech) and automation systems, the primary factor for deciding whether or not to employ such a system is the value and size of the crops that you are growing. Those growing plants as a hobby or those in a small scale commercial operation may find fertigation systems too expensive or impractical to set up.
However, for large-scale commercial growers, fertigation is incredibly viable. Cost can be recouped quickly, which would effectively increase the profitability and efficiency of their commercial operation.
The benefit that comes with having a fertigation system is undeniable. It positively impacts crop yields, lowers operating costs in the long run and mitigates environmental impacts such as water usage and leaching.
If you would like to know more about fertigation, irrigation, and other garden care requirements, feel free to reach out to us at Hills Irrigation. We have built a reputation in Australia and are willing to help you with your irrigation or fertigation needs.
Vince is Managing Director of Hills Irrigation and is supported by Lisa in an administrative capacity. Andrew, Isaac and Megan look after the day to day needs of both online and shop customers. As Project Manager, Vince is also responsible for installation projects along with his team. It is his responsibility to work closely with clients to ensure that scope of work is understood and followed.
