Drip irrigation is a system of pipes, small-bore tubing and emitters that places water or nutrient solution right at the base of each plant. A pump or pressurised line and a timer or controller decide when and how much. It is the delivery method behind most coco and rockwool fertigation and many automated soil grows.
In practice
Emitters are rated by flow, commonly 1-4 L/h; pressure-compensating types give equal flow along long lines. Use one to four emitters per pot depending on pot size, spread so the whole medium wets, and add a stake so they stay put. Filters before the emitters prevent clogging from sediment and precipitated salts. The solution can be used once (drain-to-waste) or collected and returned (recirculating).
Measure each irrigation: collect output from a test emitter and a test pot's runoff.
Don't confuse with
- Fertigation: feeding nutrients through irrigation; drip is the hardware that usually does it.
- Ebb and flow: floods a whole tray instead of feeding each pot.
Coco coir is a growing medium made from processed coconut husk, prized for holding water and air at once; it binds calcium and magnesium unless buffered.Rockwool is an inert growing medium spun from melted basalt rock into fibres, sold as plugs, cubes and slabs, that holds water and air in fixed proportions.Fertigation is delivering fertiliser dissolved in irrigation water, so plants are fed every time they are watered rather than through solid amendments.Pot size is the volume of medium a plant roots into; bigger pots give bigger plants within reason, but feeding frequency can let small pots punch well above their size.Drain-to-waste fertigation feeds each plant fresh nutrient solution and lets the runoff leave the system rather than returning it to the reservoir.A recirculating (closed) system returns drained nutrient solution to the reservoir to be reused, saving water and nutrients but needing more monitoring and sanitation.Runoff is the water or nutrient solution that drains out of the bottom of a container after irrigation; growers test it to see what is happening in the root zone.Ebb and flow (flood and drain) periodically floods a tray of potted plants with nutrient solution, then drains it back to a reservoir, pulling fresh air into the medium.High-frequency fertigation feeds small volumes of nutrient solution many times a day, keeping the root zone consistently moist and fed so small pots can produce large plants.Crop steering adjusts irrigation timing, volume and dryback, along with climate, to push plants towards vegetative growth or generative (flowering) growth.
