Fertigation as a method became widely used in the early 2000s. Basically the this is a way to supply plants with nutrients, usually in the form of fertilizers. In fact it can be used as well to bring to the soil amendments and different other materials like agricultural chemicals. Fertigation is one of the most effective ways used in order to fertilize crops because practically there is no waste of fertilizer when it is applied. The application of the fertilizer is made directly via the irrigation system together with the water itself. This fact allows precise control of the quantity and frequency of application of the fertilizer. The main principle of fertigation is to supply the growing plants with fertilizer little by little.
Usually fertigation works in the so called “fertigation systems” and it’s always combined with the existing irrigation system. Meaning that where the irrigation water goes to the same place goes the fertilizers. The distribution of nutrients in this system is controlled and they are applied only when needed and in calculated quantities. In short fertigation is simply irrigating crops with nutrient enriched water with controlled pH.
Fertigation systems can control:
• The applied quantity of fertilizer
• The length and timing of fertilizer applications
• The amount of the different fertilisers
The benefits of using fertigation can be divided in two main groups: benefits for the plants and economical ones.
Using fertigation system will help the plants grow well developed green parts. It’s essential that the roots are healthy, because they are mediator that is connecting the nutrients and the plants. The constant levels of nutrients help plants have steady nutrition regime which results in healthy plants that are less disposed to droughts and diseases.
Talking about the economic benefits on the first place must be mentioned the tree main items of expenditure these are the labor, the machinery and the cost of the fertilizers. The irrigation system is doing all the hard woks so the only manual labor is supplying the system with fertilizer, monitoring of the crops and making some adjustments if needed. The machinery is no longer needed as well. Because the fertilizer is brought to the plants in a form that can be directly absorbed there is no need for “overdosing in advance”. This overdosing results in runoff which causes pollution. So fertigation has some significant ecological benefits as well.
Methods of dosification
Quantitative method. This method is used when the fertigation system uses a fertilizing tank. The concentration is predefined and the fertilizer is applied only after the irrigation process has started.
Proportional method. In this case the fertilizers are applied by injection pumps. The concentration is fixed and proportional to the water sheet.
Methods of application of / injection the fertilizer
Continuous method. In this method the application of the fertilizer has constant rate from the begging to the end of the irrigation.
Three-stage method. The injection of the fertilizer is performed after the irrigation started and before it finished. This means that the fertilizing starts only after the soil is wet.
Proportional method. This is very simple method which is based on the proportion between the water and the fertilizer. It’s applied with constant proportions for example 1:1000 (fertilizer to water).
Quantitative method. This is the method that allows nutrients to be strictly controlled. It is allowing to apply different amounts of fertilizer to the different irrigated blocks(measured in liters of solution).
When choosing the injection method it is crucial to take the one that best suits the irrigation system and the crop to be cultivated. Incorrect injection method can damage the irrigation system and harm the effectiveness of the nutrients. For example if the pipes of the irrigation system are very long than there is a high chance that the nutrients will not reach till the end in cases like that it’s very important to install some supporting tools (like extra pumps) that will help the liquid transportation.
When using a fertigation system the issue connected to the fertilizers is very important as well. When preparing the solution there are few points that must be taken under consideration:
• Fertilizers compatibility and solubility
• Number of stock tanks
• Injection time
• Types of the fertilizers
• The use of chelates
• Reaction of fertilizers with water