There are many kinds of irrigation systems used in the greenhouses. A suitable irrigation system should be selected according to the varieties and growing conditions of crops in greenhouses. Each irrigation system has its own advantages and disadvantages and performance characteristics. It is very important to choose a suitable irrigation system for the greenhouse management.
The following are some common irrigation systems for greenhouses:
The working principle is to install valves and irrigation hose pipes on the water supply line, and manually open these control valves to conduct irrigation with the irrigation hose pipe. Such irrigation systems are common in modern greenhouses. Usually, plastic hoses made of PE, PVC and other materials are adopted as the irrigation hose pipe. It boasts the advantages of easy installation, simple use, convenient management, low cost, and resistance to blocking. The disadvantages of pipe irrigation system are large labor force, low irrigation efficiency, and difficult control of water quantity, fertilization and dosing. Therefore, this irrigation system needs to be combined with other irrigation systems such as the drip irrigation system.
The drip irrigation system is widely used in the irrigation of agricultural and forestry crops in various environments, which is a relatively water-saving irrigation method. The drip irrigation emitter is composed of the drip irrigation head, drip line pipe, drip tape, drip arrow, etc. In the greenhouse, the drip irrigation system is arranged on the surface of the greenhouse or the drip line pipe is buried 30cm underground. In the greenhouse irrigation, drip irrigation is one of the more advanced irrigation methods, which mainly has the advantages of saving water, saving labor, preventing pests, increasing production and efficiency, and easy management of water and fertilizer. The drip irrigation has higher requirements for water quality. The drip irrigation systems can be used in combination with pipe or micro sprinkler irrigation systems depending on greenhouse production conditions and climatic conditions. When the weather is hot and dry, the greenhouse climate should be adjusted by combining micro sprinkler irrigation or pipe irrigation system, while in the low temperature season, the drip irrigation system should be used.
Irrigation systems that make use of spraying water to irrigate crops are called micro sprinkler systems. The irrigation emitter is usually composed of a variety of micro sprinkler, spray gun, porous tube, etc. In general, the micro sprinkler is usually hung upside down on the greenhouse framework for irrigation in greenhouses. The micro sprinkler irrigation system has the characteristics of water saving, labor saving, energy saving, cooling and humidification, topdressing with water, and easy automatic control. But in the low-temperature and humid season, it is easy to have high humidity which may lead to increased diseases.
This so-called sprinkler machine is also a kind of micro irrigation system, but it has a high degree of irrigation uniformity and can be used on the move. The self-propelled sprinkler machine is also a walking track hanging on the framework of the greenhouse, and then it can move and spray by itself when working. These systems are typically equipped with chemical addition equipment to apply fertilizer to crops, and their nozzles and micro sprinklers can be changed depending on the crops and the purpose of spraying.
The porous pipe can be used in the micro sprinkler system or drip irrigation system by processing holes in the thin-wall plastic hose pipe to conduct irrigation. Drip irrigation under membrane in greenhouse field adopts this system. In high-temperature season, the mulching film is uncovered and can be used in the micro sprinkler irrigation. The porous pipe micro irrigation system in the greenhouse is economical and practical, which is suitable for the greenhouse and solar greenhouse. It has the characteristics of resistance to blocking and low cost, but the irrigation uniformity of this system is relatively low, and the service life is usually short.