Problems With Drip Irrigation
Underground irrigation systems were once the standard for watering lawns and gardens -- until drought, water shortages and improved understanding of how plant diseases work encouraged the development of more efficient watering methods. Of course, high-tech manufacturers soon entered the market to provide this gentler, better-targeted irrigation, declaring its superiority to sprinklers and soaker hoses alike. These new low-pressure systems provide improved water usage but, unfortunately, have their own problems.
Spray Vs. Drip
Spray irrigation, developed for installation in turfgrass, is an inefficient way to water a garden or ornamental plants. A percentage of the spray inevitably evaporates as it arcs through the air, even when the timer’s set for 4 a.m. Water lands on leaves rather than on the ground where roots need it, wasting more. Finally, water splashes in the dirt, picking up soil-borne fungi and bacteria, transporting the pathogens to the undersides of leaves. Soaker hoses put the water directly on the ground, but they may overwater areas and wash soil away from plants and roots. Drip technology steps down water pressure, reducing the 60 to 180 gallons of water used by a sprinkler to 1 to 4 gallons per hour by a drip emitter. Unfortunately, a drip system requires a new set of pressure converters, emitters and 1/2-inch line for effective operation.
A drip system provides water where it’s needed, but because of its low pressure, careful regulation must provide enough water to encourage healthy root development. To answer needs for deeper watering and overhead watering, manufacturers add a variety of pressure regulators; for ground covers, they make micro-sprinklers that use from 5 to 45 gallons per hour. Still, drip systems must run for more hours than a traditional system to achieve deep watering, and regulating a system where results are not obvious takes time and attention, particularly when hard water clogs pressure valves.
Oxygen and Salts
The same sprinkler splashing that increases humidity and transfers soil-borne pathogens to plant surfaces also drives oxygen into the soil and forces salts from water and fertilizers to percolate downward, distributing the former and dissipating the latter. Drip irrigation’s gentle nature does neither. Frequent cultivation pushes oxygen into the soil and deep watering with a hose flushes the crusty white ring, much like the white crust that forms on houseplant pots and soil, through the soil. Micro sprayers help with soil oxygen, but because only a limited area is irrigated, the salt rings remain.
The total water used in a drip system may be less than a traditional irrigation system, but components can be expensive and may not always be compatible. Drip system kits that connect directly to outside faucets might present a calibration challenge to the nonprofessional. Technology is still evolving, often making expensive equipment obsolete from year to year. Some manufacturers have solved the compatibility problem by designing pressure valves and emitter hoses and sprinklers that fit in standard irrigation systems, providing the existing system is one of theirs.
An avid perennial gardener and old house owner, Laura Reynolds has had careers in teaching and juvenile justice. A retired municipal judgem Reynolds holds a degree in communications from Northern Illinois University. Her six children and stepchildren served as subjects of editorials during her tenure as a local newspaper editor.