Efficiently design dripper irrigation systems will ensure long term durability with minimum maintenance. The ideal requirements for efficient operation of dripper systems are:

  • The delivery must be uniform and drippers must not stop easily (Capillary tubes or PC-drippers give the best results)
  • Installing drip limiters such as PC-drippers that limit flow between 1.0L.h-1 to 4.0L.h-1 provide give greatest control and efficiency.

When using spaghetti drippers (1-2 mm in diameter) ensure that the difference between the highest dripper and lowest is not more than 100mm, or that the feeder line is not higher than the lowest delivery point. This will ensure that feeder line is full of water the next time irrigation starts and that all bags receive the same amount of water (See image below).

Remember to install filters between water source (tank) and pump and the pump and drippers. Automation of irrigation cycles ensures optimum irrigation cycles and reduces wastage of expensive nutrient solution. Ideally one should regulate the irrigation cycles according to sun radiation intensity.

The thicker the spaghetti pipes are, the more water will flow out the more difficult it is to control the water flowing out. Ideally the water should drip out as there is more than enough time for the water to fill the bags.  Scheduling will also change as the growth medium becomes more dense and holds more water. So adapt your irrigation cycles accordingly as the plant grows older.

 

hydroponic bag culture system drippers slope

Installing drippers on a sloped land. Top part: bottom drippers will continuo dripping water since they are under the main dripper line water level. Bottom part: Installation of second feeder line solves the problem

 

Pressure regulated drippers are ideal when land has a slope. Normal spaghetti drippers flow rate varies considerably along the length of the irrigation line causing variations in plant growth. Pressure controlled drippers or PC-drippers have little variation but are more expensive. These PC-drippers are one of the best investments a grower can make to ensure even growth. Since flow rate is the same for all bags, wastage of nutrients is minimized.

Pressure regulated drippers are ideal when land has a slope. Normal spaghetti drippers flow rate varies considerably along the length of the irrigation line causing variations in plant growth. Pressure controlled drippers or PC-drippers have little variation but are more expensive. These PC-drippers are one of the best investments a grower can make to ensure even growth. Since flow rate is the same for all bags, wastage of nutrients is minimized.

 

PE pipe is not that expensive and adapting your irrigation system according to plant growth is part of developing and optimizing your hydroponic production system.  Don’t be scared to make changes and adding more sections into the greenhouse. It might be a little more complicated but in the end you will harvest a greater proportion of marketable yields and that is what feeds your bottom line.

During harvesting compare the higher section of the greenhouse with the lower parts. Notice if there are any differences in size of fruit, quality, colour and shape.  If you feel there is room for improvement have a look at the irrigation system. Compare the growth media and see if there is a difference in moisture content, effluent and even some fungi growing on top of the surface of the growth medium. There should not be too much difference between the bags from the higher to lower ends, if there is, you might have to change the irrigation system and separate them.