Chapter 17

Micro-Irrigation for Greenhouse Crops

(book excerpts)

The term “micro-irrigation” describes a family of irrigation systems that apply water through small emitters. In greenhouse production, emitters apply water to individual containers or individual benches. These devices deliver water onto the substrate surface very near the plant or below the substrate surface directly into the plant root zone. Rather than irrigating the entire substrate surface, as with overhead sprinklers or boom irrigation systems, micro-irrigation can deliver water precisely at the plant where nearly all the water can be used for plant growth. Because very little water spreads to the soil between the crop rows, little water is wasted. Microirrigation systems are also suited for chemigation (chemical application with irrigation water). The water and chemicals are applied directly to the container media and there are no losses between containers which eliminates runoff due to irrigation from the greenhouse. Microirrigation irrigation systems require more planning than overhead sprinkler systems because the emitter systems deliver water directly to the plant root system. The crop influences the selection of the emitter system. There are many types of emitters to meet specific needs. A well-designed and managed microirrigation system can have an efficiency of 90 to 95 percent, meaning that less than 10 percent of applied water is wasted.

Click on the following topics for more information on micro-irrigation for greenhouse crops.

Topics Within This Chapter:

  • Micro-Irrigation System Components
  • Pumping Station
  • Types of Groundwater Pumps
  • Power Units for Pumping
  • Filtration Systems
  • Main, Submain, Manifolds, and Laterals
  • Main and Submain Lines
  • Manifolds
  • Laterals
  • Flow Control Devices
  • Valves
  • Water Flow Meters
  • Types of Flow Meters
  • Pressure Gauges
  • Fertigation/Chemigation Components
  • Emitters
  • Line-Source Emitters
  • Point-Source Emitters
  • Water Flow Meters
  • Types of Flow Meters
  • Water Quality for Micro-Irrigation Systems
  • Collecting a Water Sample
  • Water Quality Analysis
  • Suspended Solids
  • Chemical Precipitation
  • Biological Growth
  • Maintenance of Micro-Irrigation Systems
  • Filter Maintenance
  • Flushing the Main Lines, Submains, and Laterals
  • Emitter Inspection
  • Chemical Injection for System Maintenance