Smart irrigation systems tailor watering schedules and run times automatically to meet specific landscape needs. These controllers significantly improve outdoor water use efficiencies. Weather-based controllers, also referred to as evapotranspiration(ET) controllers, use local weather data to adjust irrigation schedules. Evapotranspiration is the combination of evaporation from the soil surface and transpiration by plant materials. These controllers gather local weather information and make irrigation run-time adjustments so the landscape receives the appropriate amount of water.

ET weather data uses four weather parameters: temperature, wind, solar radiation and humidity. It’s the most accurate way to calculate landscape water needs.

There are three basic forms of these weather-based ET controllers:

• Signal-based controllers use meteorological data from a publicly available source and the ET value is calculated for a grass surface at the site. The ET data is then sent to the controller by a wireless connection.
• Historic ET controllers use a pre-programmed water use curve, based on historic water use in different regions. The curve can be adjusted for temperature and solar radiation.
• On-site weather measurement controllers use weather data collected on-site to calculate continuous ET measurements and water accordingly.

Types of irrigation:

• Drip irrigation.
• Sprinkler irrigation.
• Mist irrigation.

• Drip irrigation
• Sprinkler Irrigation
• Mist Irrigation

Drip irrigation

Simple drip irrigation: Low cost drip irrigation uses low-cost plastic pipes cut to the appropriate lengths laid on the ground to irrigate area. Small holes in the hose allow water to drip out and keep the base of the plant wet without wasting any water.

High cost drip irrigation: It is also referred as fully automated drip irrigation system which is controlled and monitored by using ARM9 processor. PH content and the nitrogen content of the soil are frequently monitored. For the purpose of monitoring and controlling, GSM module is implemented. The system informs user about any abnormal conditions like less moisture content and temperature rise, even concentration of CO2 via SMS through the GSM module.

Sprinkler Irrigation

Sprinkler irrigation system allows application of water under high pressure with the help of a pump. It releases water similar to rainfall through a small diameter nozzle placed in the pipes. Water is distributed through a system of pipes, sprayed into air and irrigates in most of the soil type due to wide range of discharge capacity. Water saving up to 30% - 50 %

Type of Sprinkler	Precipitation Rate(mm per hour)
Low Volume Sprinkler	Less than 13
Medium Volume Sprinkler	13 - 25
Large Volume Sprinkler(Raingun)	Above 25

Wetting pattern of sprinkler irrigation

Mist irrigation

Mist irrigation is the system of spraying water on plants. While the water reaches only the root of the plant in other watering methods, this system this system delivers water on the whole plant, thus keeping it cool and wet. For plants belonging to the orchid family, moisture in the atmosphere is important besides water.

The plants absorb water best in this method. There are a lot of differences between drip irrigation and mist irrigation, the major one being the emitters. The difference is in the way water falls on the plants and the plants using it.

The pipes bringing water and the machines are same as that in the drip irrigation system. However, in drip irrigation, the pipes are laid on the floor level. But in mist irrigation, the pipes are fixed above the plants.

The amount of water is fixed based on the size of the holes in the emitter. Good quality emitters spray only 10 litres of water in an hour. Cheap ones ones spend 35 to 40 litres in an hour.