Fertigation: approaches, systems and fertilizers in use

Fertigation, as the name implies, is the process in which fertilizers are being applied with the irrigation water: Fertilization + Irrigation. The fertilizer solutions are prepared in advance in stock tanks and the solution is then injected into the irrigation water. Fertigation has various advantages over other fertilization methods, and when properly used, it saves time and money.

Some of the advantages are: 

•   Fertilizer application is more accurate and uniform
•   Fertilizers are applied to specific areas, where they are needed
•   Nutrient are immediately available to plants
•   Uptake of nutrients by roots is improved
•   It saves labor
•   It helps to save water, because plants develop a healthier root system
•   Nutrient losses are minimized 

Fertigation approaches

The most common fertigation approaches are the quantitative approach and the proportional approach. The quantitative approach is commonly used in open fields. The grower first decides how much fertilizer has to be applied per area (e.g. kg/ha, lbs/acre). This quantity of fertilizer is then delivered through the irrigation water. The proportional approach is mostly used in soil-less media and sandy soils. Here, a defined quantity of fertilizer stock solution is injected into each unit of water flowing through the irrigation system (e.g. l/m3, lbs/gal). Nutrient levels are determined by their concentration in the irrigation water. Most growers who use proportional approach, use units of ppm (parts per million) or mmol/l.

Fertigation systems

Effective fertigation requires knowledge and proper management, since fertilizer application is an integral part of the irrigation system. Therefore, the system has to be properly designed.

To learn more about the design of the system, read our articles about fertilizer injectors.

Fertilizers used in fertigation

Not all fertilizers can be used in fertigation: only water soluble fertilizers and liquid fertilizers are appropriate. Different fertilizers differ in their solubility. Read more about solubility of fertilizers

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