This article throws light upon the top six watering system for green house crops. The watering system are: 1. Hand Watering 2. Perimeter Watering System 3. Tube Watering System 4. Drip Irrigation System 5. Overhead Spray System 6. Ebb and Flow System.
1. Hand Watering:
It is most common but most uneconomical and expensive system of watering but still is followed where labour is cheap and scale of operation is rather small and automation is not practiced. Hand watering requires considerable time and it is not pleasant work. But still it is followed where crops is at high density like nursery production, seed flats or pots.
Where hand watering is practiced care should be taken that force of water should be broken either by using fine rose spray or breaker at the end of pipe so that it does not result in washing of root medium out of pots or bend and disturb structure of root medium surface.
2. Perimeter Watering System:
In this system, pipes run around the perimeters of a bench with a nozzle that sprays water root medium surface below the foliage. Thus this system is most pertinent for production of fresh flowers. The pipes may be of galvanized iron or PVC can be fixed. Rubber pipes if are used they can be rolled if it is not in use. In these pipes, nozzles are fitted at an angle of 45, 90 or 180 degree. Normally pipes of 19 mm diameters are used. Depending upon the length of beds, valve may be provided accordingly.
3. Tube Watering System:
This system is mostly used for watering the pots. Water is carried to each pot by the polyethylene micro tube. These micro tubes are available in different inner diameter varying from 0.9, 1.1, 1.3, 1.5, 1.9mm and above.
The number of pots that can be watered from a single 19 mm main water pipe will depend upon inner diameter of micro tube being used e.g., 0.9, 1.1, 1.3, 1.5 mm micro tube will be able to handle 600, 900, 700 and 400 pots, respectively. These micro tubes should be provided with a weight at the end of it so that speed of water can be broken otherwise there is a danger that pipe being thrown out of the pot and will dig a small pit in medium.
4. Drip Irrigation System:
This system is highly suitable for green house cultivation. There is a saving of 50-70% of water in comparison to conventional system of watering. It provides uniform distribution of water, nutrients, pesticides and fungicides without wastage.
Drip irrigation system delivers water to the crop using a network of main line, sub mains, lateral line with emission point spaced at regular interval along the length side. Each dipper or emitter supplies a measured precisely controlled uniform application of water, nutrients, pesticides, fungicides and growth substances directly into the root zone of plant.
Water and nutrient enter soil from emitters moving in root zone of plants through combined forces of gravity and capillary. In this way, plants get moisture and nutrient replenished immediately ensuring plants which never suffer from water stress thus enhancing quality. This results in optimum growth and high yield.
PVC pipe line is used for distribution of water from the main source to sub-lines. Drip laterals of 12-16 mm are suitably placed in each row of plants which are directly connected to sub lines. Drippers/emitters fitted to the laterals are laid just near the plant for gradual distribution of water up to the root of plants.
There should be regular maintenance of pipes by adding chlorine or other chemicals in drift line to kill bacteria and algae. Treatment with acid is also needed to dissolve calcium carbonate. Care should be taken against rodents to avoid any damage to pipes. Monitor the pipes thoroughly for any leakage which should be done regularly.
5. Overhead Spray System:
Green house crops are most easily and cheaply can be irrigated from over-head. In this system pipes are hanged over the plant from 60 cm to 180 cm above the plants. Nozzles are fitted in the pipes at 360° pattern. Care should be taken that the water should be of good quality and properly filtered so that these nozzles are not clogged.
6. Ebb and Flow System:
This is a sub irrigation system for potted and bedding plants. Pot or flats are grown in a leveled bench made of plastic or fiber glass available in various widths (1.2-2.0 m) and length is 1 m. These benches are glued to gather to make a bench of desired length and width. These benches can move over a stand. These have channels to drain out irrigation water.
There is a water tank below the bench. This tank is covered to avoid dust or algal growth. The area of watering and size of pump should be matched. To ensure watering of pot, water remains on the bench for 10 minutes and collected in tank and reused. Fertilizer may also be applied through this system of watering. Pot with bottom hole is better than side holes.