Water Management in Horticultural Crops

Fertigation equipments

1. Pressure differential method or By-pass tank system

• In this system solid fertilizers soluble in water and liquid fertilizers can be injected into the system. A tank containing fertilizer solution is connected to the irrigation pipe at the supply point. A small part of the irrigation water is diverted through the tank diluting the nutrient solution and returning to the main supply pipe. The concentration of fertilizer in the tank becomes gradually reduced with time.





2. Ventury or vacuum pump

• This system is ideal for liquid fertilizers. It has low discharge rate. The nutrient concentration and quantity controls are medium. It delivers fertilizer at constant concentration which depends on the water flow. It should be connected in parallel with the pipe line. It is a cheap system but there will be pressure drop in the system.
3. Displacement pump

• This system is also for liquid fertilizers. The concentration of nutrient and quantity control is good. The automatic control is of higher order. It is more accurate but the cost is high. Fertilizer solution is prepared in a tank from which it is pumped and injected into the irrigation system. The fertilizer solution is delivered at a constant concentration. The impeller and casing of such a pump must be made of non-corrosive material such as nylon or polycarbonates. It needs separate power source.
4. Hydraulic dosing pumps or non electric proportional injectors

• The injection mechanism is driven by the water supply under pressure. The injection rate is factory pre-set or may be chosen by an adjustable setting on injector body. The injection rate is proportional to the flow of water passing through. The resulting solution strength is constant even though the water flow varies.