What are the best practices for irrigating a greenhouse?

1 Choose the right irrigation system

There are different types of irrigation systems for greenhouses, such as drip, sprinkler, mist, or flood. Each one has its advantages and disadvantages, depending on the crop needs, the water availability, and the cost. For example, drip irrigation is efficient and precise, but it requires filters and emitters that can clog or leak. Sprinkler irrigation is easy to install and maintain, but it can cause water loss and fungal diseases. Mist irrigation is ideal for propagating cuttings and seeds, but it can increase humidity and cooling costs. Flood irrigation is cheap and simple, but it can cause waterlogging and salinity problems.

2 Monitor the water needs of your crops

Different crops have different water needs, depending on their stage of growth, their root system, their leaf area, and their transpiration rate. You need to monitor the water needs of your crops regularly, using tools such as soil moisture sensors, tensiometers, or evapotranspiration models. These tools can help you determine when and how much to irrigate, based on the soil moisture content, the crop water use, and the weather conditions. You can also use indicators such as plant appearance, leaf temperature, or wilt symptoms, but they are less reliable and accurate.

3 Adjust the irrigation frequency and duration

The frequency and duration of irrigation depend on the water needs of your crops, the irrigation system, and the environmental factors. You need to adjust them according to the season, the day length, the solar radiation, the temperature, the humidity, and the wind. Generally, you should irrigate more frequently and less duration in hot and dry conditions, and less frequently and more duration in cold and humid conditions. You should also avoid irrigating at night or during peak hours of evaporation, to reduce water loss and disease risk.

5 Maintain the irrigation system

A well-maintained irrigation system is essential for irrigating a greenhouse effectively and efficiently. You need to maintain the irrigation system by cleaning the filters, the emitters, the pipes, and the valves regularly, to prevent clogging, corrosion, or contamination. You should also flush the system with clean water or acid solutions, to remove any deposits, residues, or biofilms. You should also calibrate the system, to ensure that the water distribution and application are uniform and accurate.

6 Follow the irrigation best practices

When irrigating a greenhouse, there are some general best practices to optimize water use and crop quality. These include using mulch, plastic, or weed mats to reduce evaporation and weed growth. Automation, sensors, or timers can be used to control the irrigation schedule and volume. Fertigation is a great way to apply nutrients and water simultaneously and efficiently. Rainwater harvesting is also beneficial for collecting and storing water for irrigation, while water recycling allows for treating and reusing drainage water for irrigation.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?