What is drip irrigation? Drip, or micro-irrigation, is technology that uses a network of plastic pipes to carry a low flow of water under low pressure to plants. Water is applied much more slowly than with sprinkler irrigation. The slow, precise delivery of water directly to the plant's root zone keeps the root zone moist, but never saturated. The plants retain the proper air and water balance and avoid the stress and shock of the "drench and dry out" cycle of most other watering methods. This results in optimum growth and healthier plants.
Drip irrigation systems are more widely available and better designed for use in home gardens than ever before. Traditionally used for growing commercial vegetables, orchards, windbreaks, greenhouse and nursery plants, drip irrigation systems are well-adapted for home use. Use them in landscapes, vegetable and flower gardens and for small fruits. They are well-suited to irrigate container plants as well.
The biggest advantage a drip irrigation system has over other watering systems is its water conservation. Drip irrigation exceeds 90 percent efficiency whereas sprinkler systems are 50 percent to 70 percent efficient. It is so efficient that many water utilities exempt landscapes irrigated with drip from restrictions during drought. Note that any irrigation system is only as efficient as the watering schedule used. Any system set to water excessively, including drip, can waste water.
Drip irrigation is ideal for berm and curbside plantings. Slopes are inefficient to irrigate because gravity pulls water downhill, causing runoff and water waste. The slow rate of water applied through drip irrigation is more likely to soak in before it runs off.
Most of the disadvantages or pitfalls of drip irrigation systems are usually due to user miscalculation and inadequate planning and incompatible equipment for the area to be irrigated.
If emitters are poorly placed, too far apart or too few in number, root development may be restricted by the limited soil area wetted.
Regular maintenance inspections are needed to maintain system effectiveness-the same as with high pressure sprinkler systems. Clogs are much less likely with filtered water and proper pressure regulation used in combination with self-cleaning emitters.
A caution
Drip tubing can be a trip hazard especially for dogs and children but is less problematic if covered with mulch and fastened with wire anchor pins every 2 to 3 feet. Drip lines can also be easily cut while undertaking other landscape maintenance activities.
Installation
A drip system is easy to install for the do-it-yourselfer because the main line does not need to be trenched into the ground as is the case in sprinkler installations. If tubing is not in the ground, the wire anchors holding the tubing in place may be forced out of the ground and require reinsertion.
The point of connection to a water supply can be a pump from a well or pond, one valve among those in a high pressure sprinkler system, or a faucet (hose bib). It can even be a high pressure sprinkler head using a kit to convert it to drip. Keep in mind that other heads in that zone must be capped because sprinklers and drip cannot be mixed within the same zone.
There are two types of emitters: pressure sensitive and pressure compensating. Pressure sensitive emitters deliver a higher flow at higher water pressures. Pressure compensating emitters provide the same flow over a wide pressure range (i.e. 1 gph, 2 gph, etc.). More products made in recent years are pressure compensating. Emitters can be attached into the mainline or placed on the ends of 1/4-inch tubing.
Drip emitter placement depends on whether the soil is sand or clay. To compensate for different types of soil, locate emitters 12 inches apart in sand, 18 inches apart in loam, and 24 inches apart in clay. If one to two emitters are recommended for a plant in a clay soil, two or three may be required in a sandy soil to wet a sufficiently wide soil area.
Visit our store or one of the other local garden centers to plan your efficient drip irrigation system for your Dream Garden.
Don and Sandy Landers are owners of Dream Garden Hydroponics, LLC, 102 Dayton Road, Marietta (740) 373-4711.
