In Greenhouse cultivation, crops are grown under a artificially controlled environmental conditions viz. temperature, humidity, light intensity, ventilation, soil media, disease control, irrigation, Fertigation and other agricultural practices throughout the season irrespective of the natural conditions outside.
Read also: Mulching Sheets and its Benefits
For Greenhouse, Micro irrigation system is the best way to water plants. Drip Irrigation or Micro Sprinklers can be used. Drip irrigation is a method of controlled irrigation in which water is slowly delivered to the root system of the plants. In this method water is either dripped onto the soil surface above the roots, or directly to the root zone. It is often a method chosen over surface irrigation because it helps to reduce water evaporation.
The watering systems should ensure that water does not fall on the leaves or flowers as it leads to disease and scorching problem. In sprinkler irrigation system, water under high pressure is forced through nozzles arranged on a supporting stand at about one feet height.
Read also: Intercropping – Advantages & Disadvantages
Materials Required for Drip Irrigation System Include
- A pump unit to generate 2.8 kg/cm2 pressure
- Water filtration system – sand / silica / screen filters
- PVC tubing with dripper or emitters
Dripper can be used according to the water need of crop / hour
a) 16mm dripper at 2.8kg/cm2 pressure gives 2.65 litres/hour ( LPH).
b) 15mm dripper at 1 kg/cm2 pressure gives 1 to 4 litres per hour
Filters: Depending upon the type of water, different kinds of filters can be used.
Sand/Gravel filter: This filter is used for filtration of water obtained for open canals and reservoirs that are contaminated by organic impurities, algae etc. The filtering is done by beds of basalt or quartz.
Hydrocyclone: This type of filter is used to filter well or river water that carries sand particles.
Disc filters: This type of filter is used to remove fine particles suspended in water
Screen filters: Stainless steel screen of 120 mesh (0.13mm) size. This is used for second stage filtration of irrigation water.
Fertigation is a method of fertilizer application in which fertilizer is incorporated within the irrigation water by the drip system. In this system fertilizer solution is distributed evenly in irrigation. The availability of nutrients is very high therefore the efficiency is more.
A Venturi is a small device used in the head system for speeding the flow of the fluid, by constricting into a cone shape tube. In the restriction the fluid must increase its velocity reducing its pressure and producing a partial vacuum. As the fluid leave the constriction, its pressure increase back to the ambient or pipe level. This device injects a small amount of concentrated liquid fertilizer directly into the water lines so that greenhouse crops are fertilized with every watering.