DRIP IRRIGATION:
By Leon Springer
A drip irrigation system can save you water, time, and money, and the benefits are immediate. Drip irrigation, more than any other kind of system, helps young drought-tolerant plantings establish their root system and thrive. A drip system can be buried under soil or mulch and automated with a timer, giving your garden a natural look with carefree convenience. The beauty of a drip system is that it supports plants without being seen. A water filter installed at the beginning of the system will prevent clogging and ensure that each emitter (dripper) will always put out the proper amount of water.
Some advantages of drip
irrigation are:
1. Water Savings
Drip irrigation can save up to 50% over conventional irrigation. It can be used
on flat terrain or hillsides where wasteful run-off is avoided. Water is
applied slowly enough to allow all moisture to soak directly into the soil.
2. Healthier Plants.
The slow, regular, and uniform application of water results in healthier growth,
increased yields, and consistent quality.
3. Automation
Drip systems can be automated by adding battery timers or electric valves and
timers. This keeps soil moisture at optimum levels.
4. Low Maintenance
Drip irrigation covers a small part of the soils surface around the plant,
which minimizes the most tedious part of gardening -- weeding. Fertilizing can
also be built into the system.
5. Low Visibility
Drip irrigation tubing can be buried or left above ground. Mulching is often
used to conceal the drip system.
IRRIGATION BASICS
There are many parts to a drip irrigation system, and installing one can be a
complex procedure.
The key elements that
are considered when designing an effective system are:
1. Flow
You can measure the output of your water supply with a one or five gallon
bucket and a stop watch. Time how long it takes to fill the bucket and use that
number to calculate how much water is available per hour. Gallons per minute x
60=number of gallons per hour. If your system needs more water than the supply
will provide at one time, the system can be divided into sections with each
section scheduled for a different time.
2. Pressure (The force
pushing the flow)
Most products operate best between 20 and 40 pounds of pressure. Normal
household pressure is 40-50 pounds. Dripworks sells easy to install pressure
regulators for under $10.00.
3. Water Supply &
Quality
City and well water are easy to filter for drip irrigation systems. Pond, ditch and some well water have special
filtering needs. The quality and source
of water will dictate the type of filter necessary for your system. Sand and silt will need to be addressed
before installing your system.
The soil type will dictate how a regular drip of water on one spot will spread. Sandy soil requires closer emitter spacing as water percolates vertically at a fast rate and slower horizontally. With a clay soil water tends to spread horizontally, giving a wide distribution pattern. Emitters can be spaced further apart with clay type soil. A loamy type soil will produce a more even percolation dispersion of water. Deep rooted plants can handle a wider spacing of emitters, while shallow rooted plants are most efficiently watered slowly (low gph emitters) with emitters spaced close together. Be aware that plants with different watering needs may need their own watering circuits. On clay soil or on a hillside, short cycles repeated frequently work best. On sandy soil, applying water with higher gph emitters lets the water spread out horizontally better than a low gph emitter.
5. Elevation
Variations in elevation can cause a change in water pressure within the system.
Pressure changes by one pound for every 2.3 foot change in elevation.
Pressure-compensating emitters are designed to work in areas with large changes
in elevation or long runs. Inline emitter tubing which is 1/2" tubing with
built-in emitters, addresses changes in elevation.
6. Friction
As water moves through tubing, pressure is lost due to friction. In mainline
runs of more than 200 feet, there can be a significant drop in pressure that
can lower the output of some emitters or sprayers at the end of the line.
Pressure-compensating emitters are used in these situations as well as inline
emitter tubing.
7. Timing
Watering in a regular scheduled cycle is essential. On clay soil or hillsides,
short cycles repeated frequently work best to prevent runoff, erosion and
wasted water. In sandy soils, slow watering using low output emitters is
recommended. Timers help prevent the too-dry/too-wet cycles that stress plants
and retard their growth. They also allow for watering at optimum times such as
early morning or late evening.
8. Watering Needs
Plants with different water needs may require their own watering circuits. For
example, orchards that get watered weekly need a different circuit than a
garden that gets watered daily. Plants that are drought tolerant will need to
be watered differently than plants requiring a lot of water. There are many
choices of timers available.
FREEZE PROTECTION
In most parts of the country, there is a possibility or freezing and/or freeze
damage to a drip system. In the fall or early spring there the two areas that
need to be attended to are the beginning of the system (timer, valve and
filter) and low spots in the system where water may settle.
The following actions
are suggested:
1. Any battery timer should
be brought indoors with the batteries removed.
2. After the main water supply is shut off, all valves should be set on manual
open and any canister filter should be drained.
3. For low spots in the (solid) mainline tubing, either use a flush valve or
insert an emitter at the lowest point. As long as the tubing is not full of
water there should be no damage.
4. Another widely used practice is to blow air through the lines with a
compressor at the end of the season.
A fertilizer injector can be added to a drip irrigation system and is an efficient way to feed plants. It delivers nutrients directly to the roots of desired plants in a liquid form and is a fast and accurate way to feed an entire garden, landscape or orchard.
Dripworks, a fast growing mail-order business with many years of experience giving technical assistance to homeowners, landscapers and farmers all over the United States. Dripworks ships most orders within 24-hours and offers phone support to its customers. Request a free 72-page color catalog by calling 800-522-3747. Dripworksusa.com